ORCID Profile
0000-0001-6614-8663
Current Organisations
University of Adelaide
,
University of Padua
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Biomechanical engineering | Biomedical engineering | Marine Engineering | Dynamics, Vibration and Vibration Control | Biomechanics | Solid Mechanics | Mechanical Engineering
Scientific Instruments | Expanding Knowledge in Engineering | Navy |
Publisher: Human Kinetics
Date: 07-2017
Abstract: New applications of the critical-power concept, such as the modeling of intermittent-work capabilities, are exciting prospects for elite cycling. However, accurate calculation of the required parameters is traditionally time invasive and somewhat impractical. An alternative single-test protocol (3-min all-out) has recently been proposed, but validation in an elite population is lacking. The traditional approach for parameter establishment, but with fewer tests, could also prove an acceptable compromise. Six senior Australian endurance track-cycling representatives completed 6 efforts to exhaustion on 2 separate days over a 3-wk period. These included 1-, 4-, 6-, 8-, and 10-min self-paced efforts, plus the 3-min all-out protocol. Traditional work-vs-time calculations of CP and anaerobic energy contribution (W′) using the 5 self-paced efforts were compared with calculations from the 3-min all-out protocol. The impact of using just 2 or 3 self-paced efforts for traditional CP and W′ estimation was also explored using thresholds of agreement (8 W, 2.0 kJ, respectively). CP estimated from the 3-min all-out approach was significantly higher than from the traditional approach (402 ± 33, 351 ± 27 W, P .001), while W′ was lower (15.5 ± 3.0, 24.3 ± 4.0 kJ, P = .02). Five different combinations of 2 or 3 self-paced efforts led to CP estimates within the threshold of agreement, with only 1 combination deemed accurate for W′. In elite cyclists the 3-min all-out approach is not suitable to estimate CP when compared with the traditional method. However, reducing the number of tests used in the traditional method lessens testing burden while maintaining appropriate parameter accuracy.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 30-10-2017
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.INJURY.2017.10.040
Abstract: To identify and describe the characteristics of existing practices for postoperative weight bearing and management of tibial plateau fractures (TPFs), identify gaps in the literature, and inform the design of future research. Seven electronic databases and clinical trial registers were searched from inception until November 17th 2016. Studies were included if they reported on the surgical management of TPFs, had a mean follow-up time of ≥1year and provided data on postoperative management protocols. Data were extracted and synthesized according to study demographics, patient characteristics and postoperative management (weight bearing regimes, immobilisation devices, exercises and complications). 124 studies were included involving 5156 patients with TPFs. The mean age across studies was 45.1 years (range 20.8-72 60% male), with a mean follow-up of 34.9 months (range 12-264). The most frequent fracture types were AO/OTA classification 41-B3 (29.5%) and C3 (25%). The most commonly reported non-weight bearing time after surgery was 4-6 weeks (39% of studies), with a further 4-6 weeks of partial weight bearing (51% of studies), resulting in 9-12 weeks before full weight bearing status was recommended (55% of studies). Loading recommendations for initial weight bearing were most commonly toe-touch/<10kg (28%), 10kg-20kg (33%) and progressive (39%). Time to full weight bearing was positively correlated with the proportion of fractures of AO/OTA type C (r=0.465, p=0.029) and Schatzker type IV-VI (r=0.614, p<0.001). Similar rates of rigid (47%) and hinged braces were reported (58%), most frequently for 3-6 weeks (43% of studies). Complication rates averaged 2% of patients (range 0-26%) for abnormal varus/valgus and 1% (range 0-22%) for non-union or delayed union. Postoperative rehabilitation for TPFs most commonly involves significant non-weight bearing time before full weight bearing is recommended at 9-12 weeks. Partial weight bearing protocols and brace use were varied. Type of rehabilitation may be an important factor influencing recovery, with future high quality prospective studies required to determine the impact of different protocols on clinical and radiological outcomes.
Publisher: Elsevier BV
Date: 2021
Publisher: MDPI AG
Date: 24-10-2020
DOI: 10.3390/JCM9113411
Abstract: There is currently no accurate data on fracture displacement during the rehabilitation of pelvic ring injuries. This study investigated the use of radiostereometric analysis (RSA) in assessing the stability of C1 pelvic ring injuries stabilised with a posterior plate and an anterior external fixator. Six patients, instructed to weight-bear as tolerated after surgery, were reviewed at 2, 4, 6, 12, 26, 52 and 104 weeks. The external fixators were removed at 6 weeks. Outcomes, including the Iowa Pelvic Score (IPS), and complications were recorded. Fracture stability was assessed using measurements on plain radiographs and RSA. All patients progressed to full weight-bearing without support within 6 weeks. At 104 weeks, the IPS was excellent in four patients, good in one patient and fair in one patient. Plain radiographs showed that all fractures were well reduced, and no loss of reduction occurred over time. By contrast, RSA measurements identified displacement in all cases. The maximum three-dimensional (3D) displacement at any time point in each patient ranged from 2 to 10 mm. Two patients with the largest displacement over time had the lowest IPS. RSA also demonstrated displacements above the currently defined normal threshold through the ‘un-injured’ sacroiliac joint in the same two patients, suggesting a subtle C2 injury, missed at initial assessment. This study demonstrates the limitations of plain radiographs in assessing pelvic fracture stability and displacement during healing, and the potential of RSA to monitor more accurately the effects of stabilisation and weight-bearing on fracture stability.
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.CLINPH.2019.02.005
Abstract: The study aim was to determine if use of illicit hetamines or ecstasy is associated with abnormal excitability of the corticomotoneuronal pathway and manipulation of novel objects with the hand. Three groups of adults aged 18-50 years were investigated: in iduals with a history of illicit hetamine use, in iduals with a history of ecstasy use but minimal use of other stimulants, and non-drug users. Transcranial magnetic stimulation was delivered to the motor cortex and the electromyographic response (motor evoked potential MEP) was recorded from a contralateral hand muscle. Participants also gripped and lifted a novel experimental object consisting of two strain gauges and an accelerometer. Resting MEP litude was larger in the hetamine group (6M, 6F) than the non-drug and ecstasy groups (p < 0.005) in males but not females. Overestimation of grip force during manipulation of a novel object was observed in the hetamine group (p = 0.020) but not the ecstasy group. History of illicit hetamine use, in particular meth hetamine, is associated with abnormal motor cortical and/or corticomotoneuronal excitability in males and abnormal manipulation of novel objects in both males and females. Abnormal excitability and hand function is evident months to years after cessation of illicit hetamine use.
Publisher: Wiley
Date: 28-11-2017
DOI: 10.1002/JOR.23474
Abstract: Tibial subchondral bone plays an important role in knee osteoarthritis (OA). Microarchitectural characterization of subchondral bone plate (SBP), underlying subchondral trabecular bone (STB) and relationships between these compartments, however, is limited. The aim of this study was to characterize the spatial distribution of SBP thickness, SBP porosity and STB microarchitecture, and relationships among them, in OA tibiae of varying joint alignment. Twenty-five tibial plateaus from end-stage knee-OA patients, with varus (n = 17) or non-varus (n = 8) alignment were micro-CT scanned (17 μm/voxel). SBP and STB microarchitecture was quantified via a systematic mapping in 22 volumes of interest per knee (11 medial, 11 lateral). Significant within-condylar and between-condylar (medial vs. lateral) differences (p < 0.05) were found. In varus, STB bone volume fraction (BV/TV) was consistently high throughout the medial condyle, whereas in non-varus, medially, it was more heterogeneously distributed. Regions of high SBP thickness were co-located with regions of high STB BV/TV underneath. In varus, BV/TV was significantly higher medially than laterally, however, not so in non-varus. Moreover, region-specific significant associations between the SBP thickness and SBP porosity and the underlying STB microarchitecture were detected, which in general were not captured when considering the values averaged for each condyle. As subchondral bone changes reflect responses to local mechanical and biochemical factors within the joint, our results suggest that joint alignment influences both the medial-to-lateral and the within-condyle distribution of force across the tibia, generating corresponding local bony responses (adaptation) of both the subchondral bone plate and underlying subchondral trabecular bone microarchitecture. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1927-1941, 2017.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JSAMS.2018.09.002
Abstract: To investigate whether functional overreaching affects locomotor system behaviour when running at fixed relative intensities and if any effects were associated with changes in running performance. Prospective intervention study. Ten trained male runners completed three training blocks in a fixed order. Training consisted of one week of light training (baseline), two weeks of heavy training designed to induce functional overreaching, and ten days of light taper training designed to allow athletes to recover from, and adapt to, the heavy training. Locomotor behaviour, 5-km time trial performance, and subjective reports of training status (Daily Analysis of Life Demands for Athletes (DALDA) questionnaire) were assessed at the completion of each training block. Locomotor behaviour was assessed using detrended fluctuation analysis of stride intervals during running at speeds corresponding to 65% and 85% of maximum heart rate (HR Time trial performance (effect size ±95% confidence interval (ES): 0.16±0.06 p<0.001), locomotor behaviour at 65% HR Locomotor behaviour during running at 65% HR
Publisher: Elsevier BV
Date: 08-2021
Publisher: Elsevier BV
Date: 12-2006
DOI: 10.1016/J.APMR.2006.08.346
Abstract: To develop an anatomic marker system (AMS) as an accurate, reliable method of thermal imaging data analysis, for use in cryotherapy research. Investigation of the accuracy of new thermal imaging technique. Hospital orthopedic outpatient department in England. Consecutive s le of 9 patients referred to anterior knee pain clinic. Not applicable. Thermally inert markers were placed at specific anatomic locations, defining an area over the anterior knee of patients with anterior knee pain. A baseline thermal image was taken. Patients underwent a 3-minute thermal washout of the affected knee. Thermal images were collected at a rate of 1 image per minute for a 20-minute re-warming period. A Matlab (version 7.0) program was written to digitize the marker positions and subsequently calculate the mean of the area over the anterior knee. Virtual markers were then defined as 15% distal from the proximal marker, 30% proximal from the distal markers, 15% lateral from the medial marker, and 15% medial from the lateral marker. The virtual markers formed an ellipse, which defined an area representative of the patella shape. Within the ellipse, the mean value of the full pixels determined the mean temperature of this region. Ten raters were recruited to use the program and interrater reliability was investigated. The intraclass correlation coefficient produced coefficients within acceptable bounds, ranging from .82 to .97, indicating adequate interrater reliability. The AMS provides an accurate, reliable method for thermal imaging data analysis and is a reliable tool with which to advance cryotherapy research.
Publisher: Journal of Athletic Training/NATA
Date: 09-2008
DOI: 10.4085/1062-6050-43.5.477
Abstract: Single-limb squats on a decline angle have been suggested as a rehabilitative intervention to target the knee extensors. Investigators, however, have presented very little empirical research in which they have documented the biomechanics of these exercises or have determined the optimum angle of decline used. To determine the involvement of the gastrocnemius and rectus femoris muscles and the external ankle and knee joint moments at 60° of knee flexion while performing a single-limb squat at different decline angles. Participants acted as their own controls in a repeated-measures design. We recruited 10 participants who had no pain, injury, or neurologic disorder. Participants performed single-limb squats at different decline angles. Angle-specific knee and ankle moments were calculated at 60° of knee flexion. Angle-specific electromyography (EMG) activity was calculated at 60° of knee flexion. Integrated EMG also was calculated to determine the level of muscle activity over the entire squat. An increase was seen in the knee moments (P & .05) and integrated EMG in the rectus femoris (P & .001) as the decline angle increased. A decrease was seen in the ankle moments as the decline angle increased (P = .001), but EMG activity in the gastrocnemius increased between 16° and 24° (P = .018). As the decline angle increased, the knee extensor moment and EMG activity increased. As the decline angle increased, the ankle plantar-flexor moments decreased however, an increase in the EMG activity was seen with the 24° decline angle compared with the 16° decline angle. This indicates that decline squats at an angle greater than 16° may not reduce passive calf tension, as was suggested previously, and may provide no mechanical advantage for the knee.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.INJURY.2017.05.024
Abstract: Tibial plateau fractures are complex and the current evidence for postoperative rehabilitation is weak, especially related to the recommended postoperative weight bearing. The primary aim of this study was to investigate if loading in the first 12 weeks of recovery is associated with patient reported outcome measures at 26 and 52 weeks postoperative. We hypothesized that there would be no association between loading and patient reported outcome measures. Seventeen patients, with a minimum of 52-week follow-up following fragment-specific open reduction and internal fixation for tibial plateau fracture, were selected for this retrospective analysis. Postoperatively, patients were advised to load their limb to a maximum of 20kg during the first 6 weeks. Loading data were collected during walking using force platforms. A ratio of limb loading (affected to unaffected) was calculated at 2, 6 and 12 weeks postoperative. Knee Injury and Osteoarthritis Scores were collected at 6, 12, 26 and 52 weeks postoperative. The association between loading ratios and patient reported outcomes were investigated. Compliance with weight bearing recommendations and changes in the patient reported outcome measures are described. Fracture reduction and migration were assessed on plain radiographs. No fractures demonstrated any measurable postoperative migration at 52 weeks. Significant improvements were seen in all patient reported outcome measures over the first 52 weeks, despite poor adherence to postoperative weight bearing restrictions. There were no associations between weight bearing ratio and patient reported outcomes at 52 weeks postoperative. Significant associations were identified between the loading ratio at 2 weeks and knee-related quality of life at six months (R
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 08-2012
DOI: 10.1016/J.JBIOMECH.2012.06.019
Abstract: Multiple marker sets and models are currently available for assessing foot and ankle kinematics in gait. Despite the presence of such a wide variety of models, the reporting of methodological designs remains inconsistent and lacks clearly defined standards. This review highlights the variability found when reporting biomechanical model parameters, methodological design, and model reliability. Further, the review clearly demonstrates the need for a consensus of what methodological considerations to report in manuscripts, which focus on the topic of foot and ankle biomechanics. We propose five minimum reporting standards, that we believe will ensure the transparency of methods and begin to allow the community to move towards standard modelling practice. The strict adherence to these standards should ultimately improve the interpretation and clinical useability of foot and ankle marker sets and their corresponding models.
Publisher: Baishideng Publishing Group Inc.
Date: 2013
Publisher: Elsevier BV
Date: 04-2018
DOI: 10.1016/J.JOCA.2018.01.014
Abstract: To study, in end-stage knee osteoarthritis (OA) patients, relationships between indices of in vivo dynamic knee joint loads obtained pre-operatively using gait analysis, static knee alignment, and the subchondral trabecular bone (STB) microarchitecture of their excised tibial plateau quantified with 3D micro-CT. Twenty-five knee OA patients scheduled for total knee arthroplasty underwent pre-operative gait analysis. Mechanical axis deviation (MAD) was determined radiographically. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four subregions (anteromedial, posteromedial, anterolateral, posterolateral). Regional differences in STB microarchitecture and relationships between joint loading and microarchitecture were examined. STB microarchitecture differed among subregions (P < 0.001), anteromedially exhibiting highest bone volume fraction (BV/TV) and lowest structure model index (SMI). Anteromedial BV/TV and SMI correlated strongest with the peak external rotation moment (ERM r = -0.74, r = 0.67, P < 0.01), despite ERM being the lowest (by factor of 10) of the moments considered, with majority of ERM measures below accuracy thresholds medial-to-lateral BV/TV ratios correlated with ERM, MAD, knee adduction moment (KAM) and internal rotation moment (|r|-range: 0.54-0.74). When controlling for walking speed, KAM and MAD, the ERM explained additional 11-30% of the variations in anteromedial BV/TV and medial-to-lateral BV/TV ratio (R This preliminary study suggests significant associations between tibial plateau STB microarchitecture and knee joint loading indices in end-stage knee OA patients. Particularly, anteromedial BV/TV correlates strongest with ERM, whereas medial-to-lateral BV/TV ratio correlates strongest with indicators of medial-to-lateral joint loading (MAD, KAM) and rotational moments. However, associations with ERM should be interpreted with caution.
Publisher: Elsevier BV
Date: 03-2019
DOI: 10.1016/J.JBIOMECH.2019.01.031
Abstract: Marker-based dynamic functional or regression methods are used to compute joint centre locations that can be used to improve linear scaling of the pelvis in musculoskeletal models, although large errors have been reported using these methods. This study aimed to investigate if statistical shape models could improve prediction of the hip joint centre (HJC) location. The inclusion of complete pelvis imaging data from computed tomography (CT) was also explored to determine if free-form deformation techniques could further improve HJC estimates. Mean Euclidean distance errors were calculated between HJC from CT and estimates from shape modelling methods, and functional- and regression-based linear scaling approaches. The HJC of a generic musculoskeletal model was also perturbed to compute the root-mean squared error (RMSE) of the hip muscle moment arms between the reference HJC obtained from CT and the different scaling methods. Shape modelling without medical imaging data significantly reduced HJC location error estimates (11.4 ± 3.3 mm) compared to functional (36.9 ± 17.5 mm, p = <0.001) and regression (31.2 ± 15 mm, p = <0.001) methods. The addition of complete pelvis imaging data to the shape modelling workflow further reduced HJC error estimates compared to no imaging (6.6 ± 3.1 mm, p = 0.002). Average RMSE were greatest for the hip flexor and extensor muscle groups using the functional (16.71 mm and 8.87 mm respectively) and regression methods (16.15 mm and 9.97 mm respectively). The effects on moment-arms were less substantial for the shape modelling methods, ranging from 0.05 to 3.2 mm. Shape modelling methods improved HJC location and muscle moment-arm estimates compared to linear scaling of musculoskeletal models in patients with hip osteoarthritis.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.INJURY.2017.10.038
Abstract: Trans arterial embolization (TAE) can stem uncontrolled bleeding associated with pelvic fractures, but is associated with potential complications. This study investigated and compared the early to midterm complications in two patient cohorts: one who did and one who did not undergo TAE. The results of 14 patients who underwent TAE in the resuscitation phase, and then had their pelvic fractures managed non-operatively, the study group (Group 1), were compared with those of a control group (Group 2) of 14 patients matched for age, sex, injury and management, that did not undergo TAE. All patients were examined clinically and answered a questionnaire on bowel and urinary function, pain and limp. Gluteus medius structure and volume were assessed on MRI. The hip girdle muscle function was assessed using a hand held dynamometer, surface electromyography as well as quantitative gait analysis. Seven patients in Group 1 (50%), but none in Group 2, had persistent urological dysfunctions, in the absence of any recognized previous pathology or urologic trauma at the time of injury. No gluteal muscle demonstrated fibrosis or fatty infiltration. The median gluteal muscle volume was not significantly decreased compared with the uninjured side in either group (P=0.421). The muscle strengths of gluteus maximus, gluteus medius, tensor fasciae latae and iliopsoas when compared to the uninjured side were significantly less in Group 1 compared to Group 2. However, no patient had a discernable limp and gait analysis showed no significant differences between the left and right sides in the study and control groups in the gluteal activation timing (p=0.171 and 0.354) and duration (p=0.622 and 0.435). There were no skin complications, and no patient reported any persistent bowel dysfunction. TAE was associated with a high rate of persistent urological dysfunction. TAE could lead to decreased hip muscles strength, however this does not seem to affect gait.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 12-2016
Publisher: Elsevier BV
Date: 10-2021
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.JBIOMECH.2014.09.003
Abstract: Numerous methods exist to estimate the pose of the axes of rotation of the forearm. These include anatomical definitions, such as the conventions proposed by the ISB, and functional methods based on instantaneous helical axes, which are commonly accepted as the modelling gold standard for non-invasive, in-vivo studies. We investigated the validity of a third method, based on regression equations, to estimate the rotation axes of the forearm. We also assessed the accuracy of both ISB methods. Axes obtained from a functional method were considered as the reference. Results indicate a large inter-subject variability in the axes positions, in accordance with previous studies. Both ISB methods gave the same level of accuracy in axes position estimations. Regression equations seem to improve estimation of the flexion-extension axis but not the pronation-supination axis. Overall, given the large inter-subject variability, the use of regression equations cannot be recommended.
Publisher: Bioscientifica
Date: 07-2022
DOI: 10.1530/EOR-21-0067
Abstract: The purpose of this study was to investigate differences in aseptic reoperation rates between single or dual lag screw femoral nails,in the treatment of intertrochanteric fractures (ITF) in elderly patients. Electronic databases were searched for RCTs and prospective cohort studies treating elderly ITF patients with a single or dual screw femoral nails. Data for aseptic reoperation rates between single screw, dual separated screw and dual integrated screw devices were pooled using a random-effects meta-analysis with 95% CIs. Pooled proportions were compared using a N-1 chi-squared test. Complications contributing to aseptic reoperation rates were extracted, and the contribution of cut-out and periprosthetic fracture as a proportion of reoperations was analysed using a negative binomial regression model. Forty-two ( n = 42) studies were evaluated, including 2795 patients treated with a single screw device, 1309 patients treated with a dual separated screw device and 303 patients treated with a dual integrated screw device. There was no significant difference in aseptic reoperation rates between single and dual lag screw femoral nails of both separated and integrated lag screw designs. Moreover, complications of cut-out and periprosthetic fracture as a proportion of reoperations did not differ significantly between devices. The current evidence showed that aseptic reoperation rates were not significantly different between single and dual screw nails of a separated lag screw design. For dual integrated screw devices, due to insufficient evidence available, further high quality RCTs are required to allow for decisive comparisons with these newer devices.
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.JSAMS.2017.04.013
Abstract: This study investigated if gradually introducing runners to minimalist shoes during training improved running economy and time-trial performance compared to training in conventional shoes. Changes in stride rate, stride length, footfall pattern and ankle plantar-flexor strength were also investigated. Randomised parallel intervention trial. 61 trained runners gradually increased the amount of running performed in either minimalist (n=31) or conventional (n=30) shoes during a six-week standardised training program. 5-km time-trial performance, running economy, ankle plantar-flexor strength, footfall pattern, stride rate and length were assessed in the allocated shoes at baseline and after training. Footfall pattern was determined from the time differential between rearfoot and forefoot (TD The minimalist shoe group improved time-trial performance (effect size (ES): 0.24 95% confidence interval (CI): 0.01, 0.48 p=0.046) and running economy (ES 0.48 95%CI: 0.22, 0.74 p<0.001) more than the conventional shoe group. There were no minimalist shoe training effects on ankle plantar-flexor concentric (ES: 0.11 95%CI: -0.18, 0.41 p=0.45), isometric (ES: 0.23 95%CI: -0.17, 0.64 p=0.25), or eccentric strength (ES: 0.24 95%CI: -0.17, 0.65 p=0.24). Minimalist shoes caused large reductions in TD Gradually introducing minimalist shoes over a six-week training block is an effective method for improving running economy and performance in trained runners.
Publisher: Springer Science and Business Media LLC
Date: 18-07-2018
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.JMBBM.2022.105311
Abstract: Estimating strain distribution in the acetabulum before and after the development of peri-prosthetic osteolytic lesions secondary to total hip arthroplasty may assist with understanding the pathogenesis of this condition. This could be achieved by performing patient-specific finite element analysis of (1) total hip arthroplasty recipients with developed acetabular osteolytic lesions, and (2) models simulating the patient's pelvis and implant immediately after primary surgery. State of the art patient-specific total hip arthroplasty finite element analysis simulations obtain trabecular bone material properties from Hounsfield units within computed tomography (CT) scans of patients. However, this is not feasible when an implant is already in situ due to metal artefact disruption and, in turn, incorrectly reproduced Hounsfield units. Therefore, alternative methods of assigning trabecular bone material properties within such models were tested and strain results compared. It was found that assigning set material properties throughout the trabecular bone geometry was sufficient for the desired application. Simulating the primary implant and pelvis requires geometric and material based assumptions. Therefore, comparisons were made between strain values obtained from simulated primary models, from state of the art methods using material properties obtained from intact bone within a CT scan, and from models with osteolytic lesions. Strain values found using the finite element models simulating the pelvis before osteolytic lesion developed were considerably closer to those found using state of the art methods than those found for the bone loss models. These models could be used to determine relationships between strain distribution and factors such as bone loss.
Publisher: Massachusetts Medical Society
Date: 12-12-2019
Publisher: Springer Science and Business Media LLC
Date: 06-11-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2013
Publisher: Wiley
Date: 29-05-2020
DOI: 10.1002/JOR.24716
Publisher: Elsevier BV
Date: 02-2008
DOI: 10.1016/J.GAITPOST.2007.03.017
Abstract: Most previous work on the use of knee bracing and taping has focussed on sagittal plane movement. However, most bracing and taping techniques aim to modify patellar movement in the coronal and transverse planes. This study investigated the effect of patellar bracing and taping on the three-dimensional mechanics of the knee during a controlled eccentric step down task. Twelve healthy subjects were asked to conduct a slow step down exercise. The step down was conducted under three randomised conditions: (a) no intervention, (b) neutral patella taping and (c) patellofemoral bracing. A step was constructed to accommodate an AMTI force platform and to produce a step height of 20 cm. Kinematic data were collected using a six camera ProReflex motion analysis system. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical Systems Technique (CAST). The patellofemoral brace and taping led to a significant reduction in the maximum coronal and range of torsional knee angles by 5 degrees and 2 degrees , respectively (p=0.030, 0.006). The range of coronal and transverse plane knee moments was also significantly reduced by 0.15 Nm/kg and 0.03 Nm/kg (p=0.020, 0.0019). The brace was shown to be more effective in the coronal and transverse planes in comparison to taping or no intervention. Bracing and taping appear to offer coronal plane and torsional control of the knee during eccentric step descent. Coronal and transverse plane mechanics should not be overlooked when studying patellofemoral pain.
Publisher: BMJ
Date: 08-2015
Publisher: Elsevier BV
Date: 08-2015
DOI: 10.1016/J.CLINBIOMECH.2015.05.008
Abstract: Excessive deformation of soft tissues is considered to be one of the major contributing factors to discomfort and injury for in iduals who sit for long periods of time. Soft tissue deformation in research has been measured under the assumption that tissues deform uniaxially below the ischium, with very small or negligible deformations taking place in other directions. Therefore, this study describes the deformation of the gluteus maximus muscle and surrounding fat tissues in the buttock region for seated subjects. In vivo measurements of the deformation for the gluteal soft tissues were obtained from MRI scans of six seated subjects. Each subject was scanned in weight-bearing and non-weight-bearing sitting postures using a Positional MRI scanner (Fonar 0.6 Tesla Indomitable™). Deformations were measured below the ischium and the proximal femur. Deformation of the gluteus maximus was also measured in the distal direction along the thigh for each subject. Our data suggest that soft tissues undergo three-dimensional deformation with considerable components below the ischium (mean of 21.4mm) and in the distal direction along the thigh (mean of 20.3mm). Differences in muscle deformation below the ischium were also observed between obese (mean of 27.4mm) and non-obese subjects (mean of 16.5mm). Findings of this study demonstrate that tissue deformations in sitting include complex three-dimensional motions that are not well approximated by two-dimensional models.
Publisher: Human Kinetics
Date: 02-2022
Abstract: Purpose: Modeling intermittent work capacity is an exciting development to the critical power model with many possible applications across elite sport. With the Skiba 2 model validated using subelite participants, an adjustment to the model’s recovery rate has been proposed for use in elite cyclists (Bartram adjustment). The team pursuit provides an intermittent supramaximal event with which to validate the modeling of W ′ in this population. Methods : Team pursuit data of 6 elite cyclists competing for Australia at a Track World Cup were solved for end W ′ values using both the Skiba 2 model and the Bartram adjustment. Each model’s success was evaluated by its ability to approximate end W ′ values of 0 kJ, as well as a count of races modeled to within a predetermined error threshold of ±1.840 kJ. Results : On average, using the Skiba 2 model found end W ′ values different from zero ( P = .007 mean ± 95% confidence limit, –2.7 ± 2.0 kJ), with 3 out of 8 cases ending within the predetermined error threshold. Using the Bartram adjustment on average resulted in end W ′ values that were not different from zero ( P = .626 mean ± 95% confidence limit, 0.5 ± 2.5 kJ), with 4 out of 8 cases falling within the predetermined error threshold. Conclusions : On average, the Bartram adjustment was an improvement to modeling intermittent work capacity in elite cyclists, with the Skiba 2 model underestimating the rate of W ′ recovery. In the specific context of modeling team pursuit races, all models were too variable for effective use hence, in idual recovery rates should be explored beyond population-specific rates.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 07-2022
Publisher: Springer Science and Business Media LLC
Date: 07-06-2023
Publisher: Wiley
Date: 10-08-2023
DOI: 10.1002/JOR.25671
Abstract: While finite element (FE) models have been used extensively in orthopedic studies, validation of their outcome metrics has been limited to comparison against ex vivo testing. The aim of this study was to validate FE model predictions of the initial cup mechanical environment against patient‐matched in vivo measurements of acetabular cup migration using radiostereometric analysis (RSA). Tailored musculoskeletal and FE models were developed using a combination of three‐dimensional (3D) motion capture data and clinical computerized tomography (CT) scans for a cohort of eight in iduals who underwent primary total hip replacement and were prospectively enrolled in an RSA study. FE models were developed to calculate the mean modulus of cancellous bone, composite peak micromotion (CPM), composite peak strain (CPS) and percentage area of bone ingrowth. The RSA cup migration at 3 months was used to corroborate the FE output metrics. Qualitatively, all FE‐predicted metrics followed a similar rank order as the in vivo RSA 3D migration data. The two cases with the lowest predicted CPM ( µm), lowest CPS ( .0041), and high bone modulus ( MPa) were confirmed to have the lowest in vivo RSA 3D migration ( .14 mm). The two cases with the largest predicted CPM ( µm), larger CPS ( .0119) and lowest bone modulus ( MPa) were confirmed to have the largest in vivo RSA 3D migration ( .78 mm). This study enabled the first corroboration between tailored musculoskeletal and FE model predictions with in vivo RSA cup migration. Investigation of additional patient‐matched CT, gait, and RSA examinations may allow further development and validation of FE models.
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.INJURY.2018.01.025
Abstract: Classification systems such as the Schatzker and AO/OTA have been proposed for standardised assessment of tibial plateau fractures and to guide clinical decision making. However, there has been no comprehensive literature review of all classification systems for tibial plateau fractures, including assessment of their reliability. The aim of this systematic review was to identify and appraise previously established classification systems for tibial plateau fractures and determine their reliability for fracture classification. Six databases were searched from inception until October 2016. Classification systems for tibial plateau fractures were identified. No restriction was placed on imaging modality (plain film X-ray, CT, MRI). Data synthesis was performed to identify common features of the systems, their prevalence within the literature and studies of intra and inter-rater reliability of fracture classification using Kappa coefficient (κ). Thirty-eight classification systems were identified, five of which were a sub-classification of a single fracture type from a previous tool. The Schatzker and AO/OTA classification systems were the most commonly reported. Of the tools identified only five have been tested for inter and intra-observer reliability (Schatzker, AO/OTA, Duparc, Hohl and Luo). Reliability of more simplistic classification systems, such as that by Luo et al. (three-column) was typically high (intra-κ = 0.67-0.81, inter-κ = 0.71-0.87), but with the disadvantage of providing less information on fracture patterns and morphology. Intra and inter-observer reliability using plain film X-ray was frequently moderate (κ = 0.40-0.60), with 2D and 3D CT typically improving reliability of classification. Only 11 of the 32 complete classification systems identified association of fracture classification with clinical outcome. Frequently used systems for classification of tibial plateau fractures display moderate intra and inter-observer reliability. More sophisticated imaging modalities such as 2D and 3D CT typically improve reliability estimates. Using fracture classification based on imaging findings to predict clinical outcome was not a commonly reported goal of newly developed systems. More detailed assessment of fracture patterns and morphology, in conjunction with information on surgical fixation, may be desirable for predicting outcomes and to guide clinical decision making.
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.KNEE.2022.08.019
Abstract: Information regarding the loading of key anatomical structures of the knee during kneeling would enhance existing functional tests, yet current visualisation methods are limited and require further development. (1) Develop a knee loading visualisation technique to investigate loading patterns of the knee during kneeling and (2) determine the utility of the technique in combination with vertical ground reaction forces and centre of pressure data in the lab-based Aberdeen Weight-Bearing Test (Knee) by assessing their reliability. Fourteen healthy participants conducted kneeling tasks with and without knee pads across two testing sessions. Eight force-sensitive resistors were affixed to the right knee throughout different kneeling tasks: upright kneeling, and reaching forward, back, left, and right. A photo of the force-sensitive resistor configuration was used to generate participant-specific heat maps of knee loading. Two in-ground force platforms were used to measure vertical ground reaction forces and centre of pressure. The inferior patella tendon showed the highest proportion of activation during both bare and knee pad kneeling for all kneeling tasks. Knee pads reduced the repeatability of knee loading patterns. Force-sensitive resistor activation and vertical ground reaction force components of the lab-based Aberdeen Weight-Bearing Test (Knee) were shown to be reliable, whereas the centre of pressure data was unreliable. We have developed a lab-based technique for visualising knee loading using force-sensitive resistors. The combination of force-sensitive resistor activation and vertical ground reaction force data provides valuable insights into both the magnitude and locations of applied loads throughout kneeling.
Publisher: Springer Science and Business Media LLC
Date: 24-07-2014
DOI: 10.1007/S00167-013-2616-7
Abstract: Preoperative function has been shown to persist posttotal knee arthroplasty. However, it remains unclear whether asymmetries are task specific. Therefore, we investigated postoperative asymmetries in loading during quiet stance and walking gait. Ten patients with end-stage knee osteoarthritis scheduled for total knee arthroplasty were studied at baseline (preoperative), 6-week, 3- and 6-month postoperative. Load distribution and balance were quantified during quiet stance. Furthermore, dynamic loading was quantified during walking gait. Patient satisfaction was assessed using the Knee Osteoarthritis and injury Outcome Score. Preoperatively, load distribution was significantly different between limbs, with approximately 70% of the load through the contralateral or 'good' side. Asymmetries persisted and up to 6-month postoperative during quiet stance. No significant change was found in balance. During walking, preoperative loading asymmetry was present however, no significant postoperative loading asymmetries were identified. Total knee arthroplasty does not appear to significantly change load distribution or balance 6-month postoperative during quiet stance however, during walking gait, symmetry appears to be restored. This could be potentially improved through enhanced rehabilitation. Therapeutic study, Level IV.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.GAITPOST.2015.12.006
Abstract: The presence of long-range correlations (self-similarity) in the stride-to-stride fluctuations in running stride interval has been used as an indicator of a healthy adaptable system. Changes to footfall patterns when running with minimalist shoes could cause a less adaptable running gait. The purpose of this study was to investigate stride interval variability and the degree of self-similarity of stride interval in runners wearing minimalist and conventional footwear. Twenty-six trained habitual rearfoot footfall runners, unaccustomed to running in minimalist footwear, performed 6-min sub-maximal treadmill running bouts at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes. Force sensitive resistors were placed in the shoes to quantify stride interval (time between successive foot contacts). Footfall position, stride interval mean and coefficient of variation (CV), were used to assess performance as a function of shoe type. Long-range correlations of stride interval were assessed using detrended fluctuation analysis (α). Mean stride interval was 1-1.3% shorter (P=0.02) and 27% of runners adopted a midfoot footfall (MFF) in the minimalist shoe. There was a significant shoe effect on α and shoe*speed*footfall interaction effect on CV (P<0.05). Runners that adopted a MFF in minimalist shoes, displayed reduced long-range correlations (P<0.05) and CV (P<0.06) in their running stride interval at the 15 km·h(-1) speed. The reduced variability and self-similarity observed for runners that changed to a MFF in the minimalist shoe may be suggestive of a system that is less flexible and more prone to injury.
Publisher: Springer Science and Business Media LLC
Date: 14-04-2015
DOI: 10.1007/S00221-015-4276-Y
Abstract: This study examined the effects of handedness on the inter-digit coordination of force variability with and without concurrent visual feedback during sustained precision pinch. Twenty-four right-handed subjects were instructed to pinch an instrumented apparatus with their dominant and non-dominant hands, separately. During the pinch, the subjects were required to maintain a stable force output at 5 N for 1 min. Visual feedback was given for the first 30 s and removed for the second 30 s. Coefficient of variation and detrended fluctuation analysis were employed to examine the amount and structural variability of the thumb and index finger forces. Similarly, correlation coefficient and detrended cross-correlation analysis were applied to quantify the inter-digit correlation of force amount and structural variability. Results showed that, compared to the non-dominant hand, the dominant hand had higher inter-digit difference in the amount of digit force variability. Without visual feedback, the dominant hand exhibited lower digit force structural variability but higher inter-digit force structural correlation than the non-dominant hand. These results implied that the dominant hand would be more independent, less flexible and with lower dynamic degrees of freedom than the non-dominant hand in coordination of the thumb and index finger forces during sustained precision pinch. The effects of handedness on inter-digit force coordination were dependent on sensory condition, which shed light on higher-level sensorimotor mechanisms that may be responsible for the asymmetries in coordination of digit force variability.
Publisher: Wiley
Date: 14-07-2015
DOI: 10.1002/JOR.22969
Abstract: Total knee arthroplasty (TKA) in people with knee osteoarthritis increases knee-specific and general physical function, but it has not been established if there is a relationship between changes in these elements of functional ability. This study investigated changes and relationships between knee biomechanics during walking, physical activity, and use of time after TKA. Fifteen people awaiting TKA underwent 3D gait analysis before and six months after surgery. Physical activity and use of time were determined in free-living conditions from a high resolution 24-h activity recall. After surgery, participants displayed significant improvements in sagittal plane knee biomechanics and improved their physical activity profiles, standing for 105 more minutes (p=0.001) and performing 64 min more inside chores on average per day (p=0.008). Changes in sagittal plane knee range of motion (ROM) and peak knee flexion positively correlated with changes in total daily energy expenditure, time spent undertaking moderate to vigorous physical activity, inside chores and passive transport (r=0.52-0.66, p=0.005-0.047). Restoration of knee function occurs in parallel and is associated with improvements in physical activity and use of time after TKA. Increased functional knee ROM is required to support improvements in total and context specific physical activity.
Publisher: Human Kinetics
Date: 07-2018
Abstract: Purpose : With knowledge of an in idual’s critical power and W ′, the SKIBA 2 model provides a framework with which to track W ′ balance during intermittent high-intensity work bouts. There are fears that the time constant controlling the recovery rate of W ′ ( τ W ′ ) may require refinement to enable effective use in an elite population. Methods : Four elite endurance cyclists completed an array of intermittent exercise protocols to volitional exhaustion. Each protocol lasted approximately 3.5–6 min and featured a range of recovery intensities, set in relation to the athlete’s critical power ( D CP ). Using the framework of the SKIBA 2 model, the τ W ′ values were modified for each protocol to achieve an accurate W ′ at volitional exhaustion. Modified τ W ′ values were compared with equivalent SKIBA 2 τ W ′ values to assess the difference in recovery rates for this population. Plotting modified τ W ′ values against D CP showed the adjusted relationship between work rate and recovery rate. Results : Comparing modified τ W ′ values against the SKIBA 2 τ W ′ values showed a negative bias of 112 (46) s (mean ± 95% confidence limits), suggesting that athletes recovered W ′ faster than predicted by SKIBA 2 ( P = .0001). The modified τ W ′ – D CP relationship was best described by a power function: τ W ′ = 2287.2 × D CP –0.688 ( R 2 = .433). Conclusions : The current SKIBA 2 model is not appropriate for use in elite cyclists, as it underpredicts the recovery rate of W ′. The modified τ W ′ equation presented will require validation but appears more appropriate for high-performance athletes. In idual τ W ′ relationships may be necessary to maximize the model’s validity.
Publisher: MDPI AG
Date: 23-03-2023
DOI: 10.3390/S23073392
Abstract: Walking gait data acquired with force platforms may be used for person re-identification (re-ID) in various authentication, surveillance, and forensics applications. Current force platform-based re-ID systems classify a fixed set of identities (IDs), which presents a problem when IDs are added or removed from the database. We formulated force platform-based re-ID as a deep metric learning (DML) task, whereby a deep neural network learns a feature representation that can be compared between inputs using a distance metric. The force platform dataset used in this study is one of the largest and the most comprehensive of its kind, containing 193 IDs with significant variations in clothing, footwear, walking speed, and time between trials. Several DML model architectures were evaluated in a challenging setting where none of the IDs were seen during training (i.e., zero-shot re-ID) and there was only one prior s le per ID to compare with each query s le. The best architecture was 85% accurate in this setting, though an analysis of changes in walking speed and footwear between measurement instances revealed that accuracy was 28% higher on same-speed, same-footwear comparisons, compared to cross-speed, cross-footwear comparisons. These results demonstrate the potential of DML algorithms for zero-shot re-ID using force platform data, and highlight challenging cases.
Publisher: Springer Science and Business Media LLC
Date: 05-04-2014
Publisher: Wiley
Date: 17-07-2021
DOI: 10.1002/JOR.25140
Abstract: Biomechanical factors (e.g., joint loading) have a significant role in the progression of osteoarthritis (OA). However, some relationships between in vivo joint loading indices and tibial cartilage thickness are conflicting. This study investigated relationships between pre‐operative in vivo external knee joint moments, joint alignment and regional tibial cartilage thickness using micro‐CT in subjects with end‐stage knee OA. Tibial plateaus from 25 patients that underwent knee replacement for OA were micro‐CT scanned (17 µm/voxel). Prior to surgery, subjects underwent gait analysis to calculate external knee moments. The mechanical axis deviation (MAD) was obtained from pre‐operative radiographs. Cartilage thickness (Cart.Th) was analyzed from micro‐CT images, in anteromedial, anterolateral, posteromedial and posterolateral subregions of interest. Medial‐to‐lateral Cart.Th ratios were also explored. Relationships between Cart.Th and joint loading indices were examined using Pearson's correlations. Significant correlations were found between Cart.Th and joint loading indices, positive anteromedially with the first peak knee adduction moment ( r = 0.55, p 0.01) and external rotation moment (ERM r = 0.52, p 0.01), and negative with MAD ( r = −0.76, p 0.001). In the lateral regions, these correlations had opposite signs. The medial‐to‐lateral Cart.Th ratio correlated strongly with ERM ( r = 0.63, p = 0.001) and MAD ( r = −0.75, p 0.001). Joint loading indices correlated with regional cartilage thickness values and their medial‐to‐lateral ratios in end‐stage knee OA subjects, with higher regional loads corresponding to thinner cartilage. These relationships have the opposite sign compared to the subchondral bone microarchitecture found in our previous study on the same specimens, which may suggest a complementary bone–cartilage interplay in response to loading.
Publisher: Wiley
Date: 13-07-2018
DOI: 10.1002/JOR.24057
Abstract: We investigated if time between injury and surgery affects cancellous bone properties in patients suffering tibial plateau fractures (TPF), in terms of structural integrity and gene expression controlling bone loss. A cohort of 29 TPF, operated 1–17 days post‐injury, had biopsies from the fracture and an equivalent contralateral limb site, at surgery. S les were assessed using micro‐computed tomography and real‐time RT‐PCR analysis for the expression of genes known to be involved in bone remodeling and fracture healing. Significant decreases in the injured vs control side were observed for bone volume fraction (BV/TV, −13.5 ± 6.0%, p = 0.011), trabecular number (Tb.N, −10.5 ± 5.9%, p = 0.041) and trabecular thickness (Tb.Th, −4.6 ± 2.5%, p = 0.033). Changes in these parameters were more evident in patients operated 5–17 days post‐injury, compared to those operated in the first 4 days post‐injury. A significant negative association was found between Tb.Th ( r = −0.54, p 0.01) and BV/TV ( r = −0.39, p 0.05) in relation to time post‐injury in the injured limb. Both BV/TV and Tb.Th were negatively associated with expression of key molecular markers of bone resorption, CTSK , ACP5 , and the ratio of RANKL : OPG mRNA. These structure/gene expression relationships did not exist in the contralateral tibial plateau of these patients. This study demonstrated that there is a significant early time‐dependent bone loss in the proximal tibia after TPF. This bone loss was significantly associated with altered expression of genes typically involved in the process of osteoclastic bone resorption but possibly also bone resorption by osteocytes. The mechanism of early bone loss in such fractures should be a subject of further investigation. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2865–2875, 2018.
Publisher: BMJ
Date: 02-2020
DOI: 10.1136/BMJOPEN-2019-032640
Abstract: Intertrochanteric fractures are common fragility injuries in the elderly. Surgical fixation using intramedullary devices are one of the widely used management options. To date, evidence demonstrating the effects of lag screw configuration and the mode of lag screw locking in these devices is lacking. The purpose of this study is to investigate whether the lag screw configuration (single vs integrated dual interlocking screw) and the mode of lag screw locking (static vs dynamic) of a femoral nail device result in differences in clinical and functional outcomes. A multicentre, pragmatic, single-blinded randomised controlled trial (RCT) with a three-arm parallel group design is proposed. Nine-hundred patients with intertrochanteric fractures (A1 and A2 AO/OTA) will be randomised to fracture treatment using a Gamma3 nail (Stryker proximally dynamic) or a Trigen Intertan nail (Smith & Nephew) in a dynamic or static lag screw configuration. The primary outcome measure consists of radiological evidence of construct failure within 6 months following surgery, with failure being defined as breakage of the femoral nail or distal locking screw, a change in tip-apex distance of more than 10 mm or lag screw cut-out through the femoral head. Secondary outcomes include surgical data (operation time, fluoroscopy time), complications (surgical site infection, reoperation, patient death), return to mobility and home circumstances, functional independence, function and pain. Patients who are able to walk independently with or without a mobility aid and are able to answer simple questions and follow instructions will be asked to participate in three dimensional gait analysis at 6 weeks and 6 months to assess hip biomechanics from this cohort. Additional secondary measures of gait speed, hip range of motion, joint contact and muscle forces and gross activity monitoring patterns will be obtained in this subgroup. The Central Adelaide Local Health Network Human Research Ethics Committee has approved the protocol for this RCT (HREC/17/RAH/433). The results will be disseminated via peer-reviewed publications and presentations at relevant conferences. ACTRN12618001431213.
Publisher: Elsevier BV
Date: 05-2013
DOI: 10.1016/J.ARTH.2012.09.021
Abstract: A systematic literature review was conducted to identify the best available evidence describing the differences in clinical outcome associated with the different methods of total knee replacement (TKR) fixation. Randomized trials published between 1980 and January 2011 comparing differences in clinical outcome scores between groups allocated to either cemented or uncemented fixation for TKR were included. Nine of the 11 studies included in the review reported no significant differences in clinical outcomes between groups with either cemented or uncemented prosthesis components. Critical appraisal of methodological bias revealed consistent shortcomings in study design and execution. It is apparent that more rigorous studies with longer follow-up periods are required to verify which method of fixation may be preferable in enhancing clinical outcomes.
Publisher: Wiley
Date: 22-08-2023
DOI: 10.1002/JOR.25427
Abstract: Proximal femur fractures in the elderly are associated with significant loss of independence, mobility, and quality of life. This prospective study aimed to: (1) investigate gait biomechanics in intertrochanteric fracture (ITF) patients (A1 and A2 AO/OTA) managed via femoral nailing at 6 weeks and 6 months postoperative and how these compared with similarly aged elderly controls and (2) investigate whether femoral offset shortening (FOS) and lateral lag screw protrusion (LSP) were associated with changes in gait biomechanics at postoperative time points. Hip radiographs and gait data were collected for 34 patients at 6 weeks and 6 months postoperatively. Gait data were also collected from similarly aged controls. FOS and LSP were measured from radiographs. Joint angles, external moments, and powers were calculated for the hip, knee, and ankle and compared between time points in ITF patients and healthy controls using statistical parametric mapping. The relationship between radiographic measures with gait speed, step length, peak hip abduction, and maximum hip abduction moment was assessed using a Pearson correlation. External hip adduction moments and hip power generation improved in the first 6 months postoperative, but differed significantly from healthy controls during single limb stance. LSP showed a moderate correlation with maximum hip abduction moment at 6 weeks postoperative ( r = −0.469, p = 0.048). These results provide new detail on functional outcomes after ITF and potential mechanisms that functional deficiencies may stem from. Lag screw prominence may be an important factor in maintaining functional independence and minimizing the risk of secondary falls after ITF in the elderly.
Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.JOCA.2017.06.001
Abstract: To (1) stratify patient subgroups according to their distinct walking gait patterns in end-stage knee osteoarthritis (OA) (2) compare measures of joint loading and proximal tibia subchondral trabecular bone (STB) microarchitecture among these gait subgroups. Twenty-five knee OA patients undergoing total knee arthroplasty (TKA) had pre-operative gait analysis. Following surgery, excised tibial plateaus were micro-CT-scanned and STB microarchitecture analysed in four tibial condylar regions of interest. Peak knee moments were input to k-means cluster analysis, to identify subgroups with homogeneous gait patterns. Joint loading and STB microarchitecture parameters were compared among gait subgroups (Kruskal-Wallis, Bonferroni-corrected Mann-Whitney U tests). Three gait subgroups were revealed: biphasics (n = 7), flexors (n = 9), counter-rotators (n = 9). Peak knee adduction moment (KAM) and KAM impulse were significantly higher (P < 0.05) in biphasics than in flexors and counter-rotators (KAM = -0.65, -0.40 and -0.21 Nm/kg, respectively), suggesting a higher medial-to-lateral tibiofemoral load ratio in biphasics. Interestingly, STB medial-to-lateral bone volume fraction (BV/TV) ratio was also significantly higher (more than double) in biphasics and flexors than in counter-rotators (2.24, 2.00 and 1.00, respectively), whereas in biphasics it was only 10% higher than in flexors and not significantly so. Within the confines of the limited s le size, data suggests that different mechanisms between the biphasic and flexor gait subroups may generate comparable loads upon the tibial plateau and corresponding bony responses, despite significantly lower KAM indices in flexors. Hence, in flexor gait OA patients, conservative treatments designed to reduce KAM, may not be appropriate. Understanding joint loading among walking gait patterns and relationships to bone microarchitecture may aid at identifying/improving management of persons at risk for developing knee OA.
Publisher: SAGE Publications
Date: 23-02-2015
Abstract: Proprioception is a vital aspect of motor control and when degraded or lost can have a profound impact on function in erse clinical populations. This systematic review aimed to identify clinically related tools to measure proprioceptive acuity, to classify the construct(s) underpinning the tools, and to report on the clinimetric properties of the tools. We searched key databases with the pertinent search terms, and from an initial list of 935 articles, we identified 57 of relevance. These articles described 32 different tools or methods to quantify proprioception. There was wide variation in methods, the joints able to be tested, and the populations s led. The predominant construct was active or passive joint position detection, followed by passive motion detection and motion direction discrimination. The clinimetric properties were mostly poorly evaluated or reported. The Rivermead Assessment of Somatosensory Perception was generally considered to be a valid and reliable tool but with low precision other tools with higher precision are potentially not clinically feasible. Clinicians and clinical researchers can use the summary tables to make more informed decisions about which tool to use to match their predominant requirements. Further discussion and research is needed to produce measures of proprioception that have improved validity and utility.
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.GAITPOST.2014.09.002
Abstract: To investigate in-shoe foot kinematics, holes are often cut in the shoe upper to allow markers to be placed on the skin surface. However, there is currently a lack of understanding as to what is an appropriate size. This study aimed to demonstrate a method to assess whether different diameter holes were large enough to allow free motion of marker wands mounted on the skin surface during walking using a multi-segment foot model. Eighteen participants underwent an analysis of foot kinematics whilst walking barefoot and wearing shoes with different size holes (15 mm, 20mm and 25 mm). The analysis was conducted in two parts firstly the trajectory of the in idual skin-mounted markers were analysed in a 2D ellipse to investigate total displacement of each marker during stance. Secondly, a geometrical analysis was conducted to assess cluster deformation of the hindfoot and midfoot-forefoot segments. Where movement of the markers in the 15 and 20mm conditions were restricted, the marker movement in the 25 mm condition did not exceed the radius at any anatomical location. Despite significant differences in the isotropy index of the medial and lateral calcaneus markers between the 25 mm and barefoot conditions, the differences were due to the effect of footwear on the foot and not a result of the marker wands hitting the shoe upper. In conclusion, the method proposed and results can be used to increase confidence in the representativeness of joint kinematics with respect to in-shoe multi-segment foot motion during walking.
Publisher: Informa UK Limited
Date: 24-03-2017
DOI: 10.1080/02699052.2017.1283061
Abstract: To examine the relationship between postural alignment and mobility skills for adults after acquired brain injury (ABI). Systematic review of the literature. Seven electronic databases, grey literature and reference lists of the shortlisted publications were searched. Studies were included if participants were adults with ABI, both postural alignment and mobility were measured and analysis included a relationship between alignment and mobility. Those that met the inclusion criteria were assessed with a critical appraisal tool. The review was registered with PROSPERO, registration number CRD42015019867. Seven observational studies were included that had examined a relationship between postural alignment and mobility after ABI. Critical appraisal scores were moderate to strong. While some studies reported that improved postural alignment was related to improved mobility after ABI, results varied and there was insufficient evidence to answer the primary question. Heterogeneous study designs did not allow meta-regression. A small amount of observational evidence exists for a relationship between postural alignment and mobility after ABI. Results vary, with some studies reporting that a more stable, upright trunk correlates with better mobility, and others providing conflicting or ambiguous results. Further research is needed to establish the relationship between postural alignment and mobility skills after ABI.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2014
Publisher: Elsevier BV
Date: 05-2020
Publisher: Elsevier BV
Date: 06-2012
DOI: 10.1016/J.ARTH.2011.08.023
Abstract: We investigated the effect several lower limb positions have on muscles that are detached to perform hip arthroplasty through posterior and lateral approaches. We used string models and computer navigation to measure the length changes in these muscles throughout hip movements in the anatomical planes and while simulating several sitting and lying postures. Piriformis and the obturators were shortened by sitting and lying postures when the femur was externally rotated and abducted the clinical implication being that such postures have the potential to best protect their repair after a posterior approach. The anterior part of gluteus medius was lengthened with femoral external rotation. This lengthening was prevented, and therefore, theoretically, the gluteus medius repair protected after a lateral approach, by neutral or internal femoral rotation.
Publisher: Wiley
Date: 30-04-2021
DOI: 10.1002/JOR.25051
Abstract: The objectives of this study were to (1) develop a semiautomated method to obtain lesion volume and bone mineral density (BMD) in terms of Hounsfield units from pelvic computed tomography (CT) scans in three regions of interest, and (2) assess accuracy and reliability of the method based on cadaveric CT scans. Image artefacts due to metal implants reduce CT clarity and are more severe with more than one implant in situ. Therefore, accuracy and reliability tests were performed with varying numbers of total hip arthroplasties implanted. To test the accuracy of lesion size measurements, microcomputed tomography was used as a reference. Mean absolute error ranged from 36 to 284 mm 3 after five measurements. Intra‐ and inter‐operator reliability of the entire method was measured for a selection of parameters. All coefficient of variation values were good to excellent for CT scans of the native pelvic anatomy and a CT scans of the same pelvis with one and two implants in situ. Accuracy of quantifying lesion volume decreased with decreasing CT image clarity by 0.6%–3.6% mean absolute relative error. Reliability of lesion volume measurement decreased with decreasing CT clarity. This was also the case for reliability of BMD measurements in the region most disrupted by metal artefact. The presented method proposes an approach for quantifying bone loss which has been proven to be accurate, reliable, and clinically applicable.
Publisher: Wiley
Date: 17-10-2023
DOI: 10.1002/JOR.25455
Abstract: The aim of this study was to determine the effect of surgical change to the acetabular offset and femoral offset on the abductor muscle and hip contact forces after primary total hip arthroplasty (THA) using computational methods. Thirty‐five patients undergoing primary THA were recruited. Patients underwent a computed tomography scan of their pelvis and hip, and underwent gait analysis pre‐ and 6‐months postoperatively. Surgically induced changes in acetabular and femoral offset were used to inform a musculoskeletal model to estimated abductor muscle and hip joint contact forces. Two experiments were performed: (1) influence of changes in hip geometry on hip biomechanics with preoperative kinematics and (2) influence of changes in hip geometry on hip biomechanics with postoperative kinematics. Superior and medial placement of the hip centre of rotation during THA was most influential in reducing hip contact forces, predicting 63% of the variance ( p 0.001). When comparing the preoperative geometry and kinematics model, with postoperative geometry and kinematics, hip contact forces increased after surgery (0.68 BW, p = 0.001). Increasing the abductor lever arm reduced abductor muscle force by 28% ( p 0.001) and resultant hip contact force by 17% (0.6 BW, p = 0.003), with both preoperative and postoperative kinematics. Failure to increase abductor lever arm increased resultant hip contact force 11% (0.33 BW, p 0.001). In conclusion, increasing the abductor lever arm provides a substantial biomechanical benefit to reduce hip abductor and resultant hip joint contact forces. The magnitude of this effect is equivalent to the average increase in hip contact force seen with improved gait from pre‐to post‐surgery.
Publisher: Informa UK Limited
Date: 04-02-2019
DOI: 10.1080/10255842.2018.1564819
Abstract: There is currently no validated full-body lifting model publicly available on the OpenSim modelling platform to estimate spinal loads during lifting. In this study, the existing full-body-lumbar-spine model was adapted and validated for lifting motions to produce the lifting full-body model. Back muscle activations predicted by the model closely matched the measured erector spinae activation patterns. Model estimates of intradiscal pressures and in vivo measurements were strongly correlated. The same spine loading trends were observed for model estimates and reported vertebral body implant measurements. These results demonstrate the suitability of this model to evaluate changes in lumbar loading during lifting.
Publisher: MDPI AG
Date: 26-02-2020
DOI: 10.3390/JCM9030626
Abstract: Tibial plateau fractures (TPFs) are challenging, requiring complex open reduction and internal fixation (ORIF) and are often associated with complications including surgical site infections (SSIs). In 2007, we introduced a novel management protocol to treat TPFs which consisted of an angiosome- or perforator-sparing (APS) anterolateral approach followed by unrestricted weight bearing and range of motion. The primary aim of this retrospective study was to investigate complication rates and patient outcomes associated with our new management protocol. In total, 79 TPFs treated between 2004 and 2007 through a classic anterolateral surgical approach formed the “Classic Group” while 66 TPFS treated between 2007 and 2013 formed the “APS Group”. Fracture reduction, maintenance of reduction and patient-reported outcomes were assessed. There was a clinically important improvement in the infection incidence with the APS (1.5%) versus the Classic technique (7.6%) (1/66 versus 2/79 for superficial infections 0/66 versus 4/79 for deep infections). Despite a more aggressive rehabilitation, there was no difference in the fracture reduction over time or the functional outcomes between both groups (p 0.05). The APS anterolateral approach improved the rate of SSIs after TPFs without compromising fracture reduction and stabilisation. We continue to use this new management approach and early unrestricted weight bearing when treating amenable TPFs.
Publisher: Springer Science and Business Media LLC
Date: 26-05-2022
DOI: 10.1186/S40814-022-01057-5
Abstract: Anterior knee pain is often reported following intramedullary nailing of tibial shaft fractures. The aetiology remains unclear, but the surgical approach may play an important role. To date, no biomechanically validated method exists to assess patient outcomes specific to anterior knee pain in this cohort. The central aims of this study are to (1) evaluate the feasibility of a full-scale randomised controlled trial (RCT) investigating the influence of surgical approach on intramedullary nailing of tibial shaft fractures (suprapatellar versus infrapatellar nailing), (2) explore differences in clinical outcomes between the approaches, and (3) explore the development of a biomechanically validated methodology for assessing post-operative anterior knee pain and knee function specific to intramedullary nailing of tibial shaft fractures. This pilot study will follow a prospective randomised controlled design at the Royal Adelaide Hospital and The Queen Elizabeth Hospital (South Australia). This study aims to recruit 60 patients between 18 and 60 years old who will be randomly assigned to either the suprapatellar or infrapatellar approach following a decision for intramedullary surgical fixation by the treating surgeon. All nails in this study will be Stryker T2 Alpha nails. Patients will undergo standard radiograph, magnetic resonance imaging, and clinical assessments in-line with their standard operative care, and complete a number of patient-reported and performance-based outcome measures. Performance-based outcome measures will be assessed utilising three-dimensional motion capture techniques. Follow-up time points are 3, 6, 12, and 18 months. Feasibility outcomes include ability to meet enrolment and retention metrics, compliance with all questionnaires and assessment procedures, and the occurrence of any adverse events. The primary clinical outcome is the incidence of anterior knee pain at 12 months after surgery. This study will establish the feasibility and inform the design of a large-scale RCT. Evaluation of all clinical data and patient outcomes will lead to the development of a new tool for assessing patient outcomes in this cohort. Limitations of the study include an unpredictable enrolment rate and loss to follow-up, small s le size, and the unknown ability of three-dimensional motion analysis to pick up the effects of anterior knee pain after tibial nailing. This trial was prospectively registered on the 7 February 2020 on ANZCTR, ACTRN12620000109909 .
Publisher: Informa UK Limited
Date: 11-01-2016
DOI: 10.1080/02640414.2015.1136071
Abstract: The purpose of this study was to determine if minimalist shoes improve time trial performance of trained distance runners and if changes in running economy, shoe mass, stride length, stride rate and footfall pattern were related to any difference in performance. Twenty-six trained runners performed three 6-min sub-maximal treadmill runs at 11, 13 and 15 km·h(-1) in minimalist and conventional shoes while running economy, stride length, stride rate and footfall pattern were assessed. They then performed a 5-km time trial. In the minimalist shoe, runners completed the trial in less time (effect size 0.20 ± 0.12), were more economical during sub-maximal running (effect size 0.33 ± 0.14) and decreased stride length (effect size 0.22 ± 0.10) and increased stride rate (effect size 0.22 ± 0.11). All but one runner ran with a rearfoot footfall in the minimalist shoe. Improvements in time trial performance were associated with improvements in running economy at 15 km·h(-1) (r = 0.58), with 79% of the improved economy accounted for by reduced shoe mass (P < 0.05). The results suggest that running in minimalist shoes improves running economy and 5-km running performance.
Publisher: Springer Science and Business Media LLC
Date: 08-08-2016
DOI: 10.1007/S00256-015-2227-0
Abstract: To investigate the reliability of a simple, efficient technique for measuring bone mineral density (BMD) in the metatarsals using dual-energy X-ray absorptiometry (DXA). BMD of the right foot of 32 trained male distance runners was measured using a DXA scanner with the foot in the plantar position. Separate regions of interest (ROI) were used to assess the BMD of each metatarsal shaft (1st-5th) for each participant. ROI analysis was repeated by the same investigator to determine within-scan intra-rater reliability and by a different investigator to determine within-scan inter-rater reliability. Repeat DXA scans were undertaken for ten participants to assess between-scan intra-rater reliability. Assessment of BMD was consistently most reliable for the first metatarsal across all domains of reliability assessed (intra-class correlation coefficient [ICC] ≥0.97 coefficient of variation [CV] ≤1.5% limits of agreement [LOA] ≤4.2%). Reasonable levels of intra-rater reliability were also achieved for the second and fifth metatarsals (ICC ≥0.90 CV ≤4.2% LOA ≤11.9%). Poorer levels of reliability were demonstrated for the third (ICC ≥0.64 CV ≤8.2% LOA ≤23.6%) and fourth metatarsals (ICC ≥0.67 CV ≤9.6% LOA ≤27.5%). BMD was greatest in the first and second metatarsals (P < 0.01). Reliable measurements of BMD were achieved for the first, second and fifth metatarsals.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Human Kinetics
Date: 03-2017
Abstract: Stride-to-stride fluctuations in running-stride interval display long-range correlations that break down in the presence of fatigue accumulated during an exhaustive run. The purpose of the study was to investigate whether long-range correlations in running-stride interval were reduced by fatigue accumulated during prolonged exposure to a high training load (functional overreaching) and were associated with decrements in performance caused by functional overreaching. Ten trained male runners completed 7 d of light training (LT 7 ), 14 d of heavy training (HT 14 ) designed to induce a state of functional overreaching, and 10 d of light training (LT 10 ) in a fixed order. Running-stride intervals and 5-km time-trial (5TT) performance were assessed after each training phase. The strength of long-range correlations in running-stride interval was assessed at 3 speeds (8, 10.5, and 13 km/h) using detrended fluctuation analysis. Relative to performance post-LT 7 , time to complete the 5TT was increased after HT 14 (+18 s P .05) and decreased after LT 10 (–20 s P = .03), but stride-interval long-range correlations remained unchanged at HT 14 and LT 10 ( P .50). Changes in stride-interval long-range correlations measured at a 10.5-km/h running speed were negatively associated with changes in 5TT performance ( r –.46 P = .03). Runners who were most affected by the prolonged exposure to high training load (as evidenced by greater reductions in 5TT performance) experienced the greatest reductions in stride-interval long-range correlations. Measurement of stride-interval long-range correlations may be useful for monitoring the effect of high training loads on athlete performance.
Publisher: Elsevier BV
Date: 07-2018
DOI: 10.1016/J.JOCA.2018.02.897
Abstract: To determine the change in walking gait biomechanics after total hip arthroplasty (THA) for osteoarthritis (OA) compared to the pre-operative gait status, and to compare the recovery of gait following THA with healthy in iduals. Systematic review with meta-analysis of studies investigating changes in gait biomechanics after THA compared to (1) preoperative levels and (2) healthy in iduals. Data were pooled at commonly reported time points and standardised mean differences (SMDs) were calculated in meta-analyses for spatiotemporal, kinematic and kinetic parameters. Seventy-four studies with a total of 2,477 patients were included. At 6 weeks postoperative, increases were evident for walking speed (SMD: 0.32, 95% confidence intervals (CI) 0.14, 0.50), stride length (SMD: 0.40, 95% CI 0.19, 0.61), step length (SMD: 0.41, 95% CI 0.23, 0.59), and transverse plane hip range of motion (ROM) (SMD: 0.36, 95% CI 0.05, 0.67) compared to pre-operative gait. Sagittal, coronal and transverse hip ROM was significantly increased at 3 months (SMDs: 0.50 to 1.07). At 12 months postoperative, patients demonstrated deficits compared with healthy in iduals for walking speed (SMD: -0.59, 95% CI -1.08 to -0.11), stride length (SMD: -1.27, 95% CI -1.63, -0.91), single limb support time (SMD: -0.82, 95% CI -1.23, -0.41) and sagittal plane hip ROM (SMD: -1.16, 95% CI -1.83, -0.49). Risk of bias scores ranged from seven to 24 out of 26. Following THA for OA, early improvements were demonstrated for spatiotemporal and kinematic gait patterns compared to the pre-operative levels. Deficits were still observed in THA patients compared to healthy in iduals at 12 months.
Publisher: Wiley
Date: 07-05-2015
DOI: 10.1002/JOR.22905
Abstract: Tibial plateau fractures are common, but little evidence exists for their postoperative management, especially when recommending if patients should weight bear at all, partially, or as tolerated. In this study, we describe the loads passing through the fracture construct and the associated fracture migration over the first year following surgery. Nine patients were treated with open reduction and internal fixation and instructed to weight bear as tolerated. Fracture loading and migration were assessed at 2, 12, 26, and 52 weeks postoperative. Fracture loading was calculated as the knee joint reaction force (peak, average, the angle of the force vector, and the point of force application) using gait analysis and an inverse dynamics musculoskeletal model. Fracture migration was assessed using radiostereometric analysis. The fractures were progressively loaded during the rehabilitation phase. The point of application of the load shifted from neutral to medial by week 26 for all patients. Migration during the first postoperative year was within current clinical acceptable limits. The peak load during walking at each time point was not associated with fracture fragment migration and does not appear to exceed the elastic limit of the fracture construct.
Publisher: Elsevier BV
Date: 04-2013
DOI: 10.1016/J.GAITPOST.2012.09.020
Abstract: Kinematic models are commonly used to quantify foot and ankle kinematics, yet no marker sets or models have been proven reliable or accurate when wearing shoes. Further, the minimal detectable difference of a developed model is often not reported. We present a kinematic model that is reliable, accurate and sensitive to describe the kinematics of the foot-shoe complex and lower leg during walking gait. In order to achieve this, a new marker set was established, consisting of 25 markers applied on the shoe and skin surface, which informed a four segment kinematic model of the foot-shoe complex and lower leg. Three independent experiments were conducted to determine the reliability, accuracy and minimal detectable difference of the marker set and model. Inter-rater reliability of marker placement on the shoe was proven to be good to excellent (ICC=0.75-0.98) indicating that markers could be applied reliably between raters. Intra-rater reliability was better for the experienced rater (ICC=0.68-0.99) than the inexperienced rater (ICC=0.38-0.97). The accuracy of marker placement along each axis was <6.7 mm for all markers studied. Minimal detectable difference (MDD90) thresholds were defined for each joint tibiocalcaneal joint--MDD90=2.17-9.36°, tarsometatarsal joint--MDD90=1.03-9.29° and the metatarsophalangeal joint--MDD90=1.75-9.12°. These thresholds proposed are specific for the description of shod motion, and can be used in future research designed at comparing between different footwear.
Publisher: Elsevier BV
Date: 12-2014
DOI: 10.1016/J.KNEE.2014.08.004
Abstract: Footwear and insoles are used to reduce knee load in people with medial knee osteoarthritis (OA), despite a limited understanding of foot function in this group. The aim of this study was to investigate the differences in foot kinematics between adults with and without medial knee OA during barefoot walking. Foot kinematics were measured during walking in 30 adults 15 with medial knee OA (mean age was 67.0 with a standard deviation (SD) of 8.9 years height was 1.66 with SD of 0.13 m body mass was 84.2 with SD of 15.8 kg BMI was 30.7 with SD of 6.2 kg/m(2) K-L grade 3: 5, grade 4: 10) and 15 aged and gender matched control participants with 12 motion analysis cameras using the IOR multi-segment foot model. Motion of the knee joint, hindfoot, midfoot, forefoot and hallux were compared between groups using clustered linear regression. The knee OA group displayed reduced coronal plane range of motion of the midfoot (mean 3.8° vs. 5.4°, effect size=1.1, p=0.023), indicating reduced midfoot mobility. There was also a reduced sagittal plane range of motion at the hallux in the knee OA group compared to the control group (mean 29.6° vs. 36.3°, effect size=1.2, p=0.008). No statistically significant differences in hindfoot or forefoot motion were observed. People with medial knee OA display altered foot function compared to healthy controls. As foot and knee function are related, it is possible that altered foot function in people with knee OA may influence the effects of footwear and insoles.
Publisher: Elsevier BV
Date: 04-2016
DOI: 10.1016/J.PARKRELDIS.2016.02.019
Abstract: The sonographic appearance of the substantia nigra is abnormally bright and enlarged (hyperechogenic) in young adults with a history of illicit stimulant use. The abnormality is a risk factor for Parkinson's disease. The aim of the current study was to identify the type of illicit stimulant drug associated with substantia nigra hyperechogenicity and to determine if in iduals with a history of illicit stimulant use exhibit clinical signs of parkinsonism. We hypothesised that use of hetamines (primarily meth hetamine) is associated with substantia nigra hyperechogenicity and clinical signs of parkinsonism. The area of echogenic signal in the substantia nigra was measured in abstinent human hetamine users (n = 27 33 ± 8 years) and in three control groups comprising a) 'ecstasy' users (n = 19 23 ± 3 years), b) cannabis users (n = 30 26 ± 8 years), and c) non-drug users (n = 37 25 ± 7 years). A subset of subjects (n = 55) also underwent a neurological examination comprising the third and fifth part of the Unified Parkinson's Disease Rating Scale. Area of substantia nigra echogenicity was significantly larger in the hetamine group (0.276 ± 0.080 cm(2)) than in the control groups (0.200 ± 0.075, 0.190 ± 0.049, 0.191 ± 0.055 cm(2), respectively P < 0.002). The score on the clinical rating scale was also significantly higher in the hetamine group (8.4 ± 8.1) than in pooled controls (3.3 ± 2.8 P = 0.002). Illicit use of hetamines is associated with abnormal substantia nigra morphology and subtle clinical signs of parkinsonism. The results support epidemiological findings linking use of hetamines, particularly meth hetamine, with increased risk of developing Parkinson's disease later in life.
Publisher: Journal of Athletic Training/NATA
Date: 10-2016
DOI: 10.4085/1062-6050-51.12.05
Abstract: Context: Minimalist shoes have been suggested as a way to alter running biomechanics to improve running performance and reduce injuries. However, to date, researchers have only considered the effect of minimalist shoes at slow running speeds. Objective: To determine if runners change foot-strike pattern and alter the distribution of mechanical work at the knee and ankle joints when running at a fast speed in minimalist shoes compared with conventional running shoes. Design: Crossover study. Setting: Research laboratory. Patients or Other Participants: Twenty-six trained runners (age = 30.0 ± 7.9 years [age range, 18−40 years], height = 1.79 ± 0.06 m, mass = 75.3 ± 8.2 kg, weekly training distance = 27 ± 15 km) who ran with a habitual rearfoot foot-strike pattern and had no experience running in minimalist shoes. Intervention(s): Participants completed overground running trials at 18 km/h in minimalist and conventional shoes. Main Outcome Measure(s): Sagittal-plane kinematics and joint work at the knee and ankle joints were computed using 3-dimensional kinematic and ground reaction force data. Foot-strike pattern was classified as rearfoot, midfoot, or forefoot strike based on strike index and ankle angle at initial contact. Results: We observed no difference in foot-strike classification between shoes (χ21 = 2.29, P = .13). Ankle angle at initial contact was less (2.46° versus 7.43° t25 = 3.34, P = .003) and strike index was greater (35.97% versus 29.04% t25 = 2.38, P = .03) when running in minimalist shoes compared with conventional shoes. We observed greater negative (52.87 J versus 42.46 J t24 = 2.29, P = .03) and positive work (68.91 J versus 59.08 J t24 = 2.65, P = .01) at the ankle but less negative (59.01 J versus 67.02 J t24 = 2.25, P = .03) and positive work (40.37 J versus 47.09 J t24 = 2.11, P = .046) at the knee with minimalist shoes compared with conventional shoes. Conclusions: Running in minimalist shoes at a fast speed caused a redistribution of work from the knee to the ankle joint. This finding suggests that runners changing from conventional to minimalist shoes for short-distance races could be at an increased risk of ankle and calf injuries but a reduced risk of knee injuries.
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.GAITPOST.2017.04.020
Abstract: Understanding the biomechanics of the foot is essential for many areas of research and clinical practice such as orthotic interventions and footwear development. Despite the widespread attention paid to the biomechanics of the foot during gait, what largely remains unknown is how the foot moves inside the shoe. This study investigated the reliability of the Adelaide In-Shoe Foot Model, which was designed to quantify in-shoe foot kinematics and kinetics during walking. Intra-rater reliability was assessed in 30 participants over five walking trials whilst wearing shoes during two data collection sessions, separated by one week. Sufficient reliability for use was interpreted as a coefficient of multiple correlation and intra-class correlation coefficient of >0.61. Inter-rater reliability was investigated separately in a second s le of 10 adults by two researchers with experience in applying markers for the purpose of motion analysis. The results indicated good consistency in waveform estimation for most kinematic and kinetic data, as well as good inter-and intra-rater reliability. The exception is the peak medial ground reaction force, the minimum abduction angle and the peak abduction/adduction external hindfoot joint moments which resulted in less than acceptable repeatability. Based on our results, the Adelaide in-shoe foot model can be used with confidence for 24 commonly measured biomechanical variables during shod walking.
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.ORCP.2019.06.003
Abstract: This study aimed to examine associations between postural control and body composition in 8-10-year-old girls. An observational cross-sectional study was conducted in 47 girls who were healthy-weight/overweight/obese [body mass index (BMI) percentile]. Girls participated in six postural control conditions of varying difficulty (standing with malleoli touching, tandem stance leading with dominant and non-dominant foot, repeated with eyes open and closed). Postural control outcomes included Centre of Pressure (COP) sway area, COP principal and minor axis length and COP maximum velocity. Data were analysed using linear mixed modelling. BMI percentile was positively associated with COP sway area (p=0.034) and principal axis (p=0.030) during tandem stance non-dominant foot leading with eyes closed and COP principal axis during tandem stance dominant foot leading with eyes open (p=0.045). BMI percentile significantly interacted with postural control conditions of varying difficulty to predict postural control outcomes (p≤0.035), notable for tandem stance positions [all four COP sway outcomes in tandem stance non-dominant foot leading eyes closed tandem stance dominant foot leading with eyes open and closed (two COP sway outcomes each)]. Girls with greater adiposity may have impairments in postural control, but only during more challenging postural control conditions. In contrast, BMI has little role to play in girls' postural control in easier postural control conditions (standing with feet together). These findings may suggest potential functional or safety considerations when girls with overweight/obesity are performing demanding postural control tasks (such as during sport or physical activity).
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.JBIOMECH.2022.111275
Abstract: Postoperative weight bearing has the potential to generate fragmental motion of surgically repaired tibial plateau fractures (TPFs), which may contribute to loss of fracture reduction. The effect of loading on the internal distribution of fragmentary displacements is currently unknown. The aim of this study was to determine the internal displacements of surgically repaired split TPFs due to a three-bodyweight load, using large-volume micro-CT imaging and image correlation. Fractures were generated and surgically repaired for two cadaveric specimens. Load was applied to the specimens inside a large-volume micro-CT system and scanned at 0.046 mm isotropic voxel size. Pre- and post-loading images were paired, co-registered, and internal fragmentary displacements quantified. Internal fragmental displacements of the cadaveric bones were compared to in vivo displacements measured in the lateral split fragments of TPFs in a clinical cohort of patients who had similar surgical repair and were prescribed pain tolerated postoperative weight bearing. The split fragments of cadaveric specimens displaced, on average, less than 0.3 mm, consistent with in vivo measurements. Specimen one rotated around the mediolateral axis, while specimen two displaced consistently caudally. Specimen two also had varying displacements along the mediolateral axis where, at the fracture site, the fragment displaced caudally and laterally, while the most lateral edge of the tibial plateau displaced caudally and medially. The methods applied in this study can be used to measure internal fragmental motion within TPFs.
Publisher: Public Library of Science (PLoS)
Date: 29-12-2014
Publisher: Wiley
Date: 25-11-2020
DOI: 10.1002/JOR.24914
Abstract: This preliminary study quantified tibia cartilage thickness (Cart.Th), subchondral bone plate thickness (SBPl.Th) and subchondral trabecular bone (STB) microarchitecture in subjects with varus‐ or valgus‐ malaligned knees diagnosed with end‐stage knee osteoarthritis (OA) and compared them to controls (non‐OA). Tibial plateaus from 25 subjects with knee‐OA (undergoing knee arthroplasty) and 15 cadavers (controls) were micro‐CT scanned (17 µm/voxel). Joint alignment was classified radiographically for OA subjects (varus‐aligned n = 18, valgus‐aligned n = 7). Cart.Th, SBPl.Th, STB bone volume fraction (BV/TV) and their medial‐to‐lateral ratios were analyzed in anteromedial, anterolateral, posteromedial and posterolateral subregions. Varus‐OA and valgus‐OA were compared to controls. Compared to controls (1.19–1.54 mm), Cart.Th in varus‐OA was significantly lower anteromedially (0.58 mm, −59%) and higher laterally (2.19–2.47 mm, +60–63%) in valgus‐OA, Cart.Th was significantly higher posteromedially (1.86 mm, +56%). Control medial‐to‐lateral Cart.Th ratios were around unity (0.8–1.1), in varus‐OA significantly below (0.2–0.6) and in valgus‐OA slightly above (1.0–1.3) controls. SBPl.Th and BV/TV were significantly higher medially in varus‐OA (0.58‐0.72 mm and 37–44%, respectively) and laterally in valgus‐OA (0.60–0.61 mm and 32–37%), compared to controls (0.26–0.47 mm and 18–37%). In varus‐OA, the medial‐to‐lateral SBPl.Th and BV/TV ratios were above unity (1.4–2.4) and controls (0.8–2.1) in valgus‐OA they were closer to unity (0.8‐1.1) and below controls. Varus‐ and valgus‐OA tibia differ significantly from controls in Cart.Th, SBPl.Th and STB microarchitecture depending on joint alignment, suggesting structural changes in OA may reflect differences in medial‐to‐lateral load distribution upon the tibial plateau. Here we identified an inverse relationship between cartilage thickness and underlying subchondral bone, suggesting a whole‐joint response in OA to daily stimuli.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.FOOT.2015.03.005
Abstract: A clinical records audit of the University of South Australia's podiatry clinic clients attending in 2010 was undertaken to determine prevalence of symptomatic flexible pes planus, presenting reasons and treatment options most frequently used. Analysis of rearfoot measures (resting calcaneal stance position, subtalar joint range of motion) between those prescribed a vertical (heel) or inverted (heel) cast pour and a medial heel (Kirby) skive was undertaken. Of 223 clinical records audited, 50% (111/223) of clients were assessed with flexible pes planus, 77% (86/111) of clients with pes planus presented with back or lower limb pain and 58% (64/111) were prescribed customised foot orthoses. Of 42 prescriptions for customised foot orthoses audited 64% (27/42) were prescribed a vertical (heel) cast pour, 36% (15/42) an inverted (heel) cast pour and 19% (8/42) received a medial heel (Kirby) skive. Those prescribed a medial heel (Kirby) skive had a more everted resting calcaneal stance position than those that were not (mean -8.6±2.8° vs. -5.5±3.4°, p=0.02). Those prescribed an inverted (heel) cast pour had a greater range of subtalar joint motion than those prescribed a vertical (heel) cast pour (median 36.0±10.0° vs. 29.0±5.0°, p=0.01).
Publisher: Springer Science and Business Media LLC
Date: 27-08-2011
Publisher: Informa UK Limited
Date: 13-08-2019
DOI: 10.1080/17461391.2018.1505958
Abstract: This study investigated whether male runners improve running performance, running economy, ankle plantar flexor strength, and alter running biomechanics and lower limb bone mineral density when gradually transitioning to using minimalist shoes for 100% of weekly running. The study was a planned follow-up of runners (n = 50) who transitioned to minimalist or conventional shoes for 35% of weekly structured training in a previous 6-week randomised controlled trial. In that trial, running performance and economy improved more with minimalist shoes than conventional shoes. Runners in each group were instructed to continue running in their allocated shoe during their own preferred training programme for a further 20 weeks while increasing allocated shoe use to 100% of weekly training. At the 20-week follow-up, minimalist shoes did not affect performance (effect size: 0.19 p = 0.218), running economy (effect size: ≤ 0.24 p ≥ 0.388), stride rate or length (effect size: ≤ 0.12 p ≥ 0.550), foot strike (effect size: ≤ 0.25 p ≥ 0.366), or bone mineral density (effect size: ≤ 0.40 p ≥ 0.319). Minimalist shoes increased plantar flexor strength more than conventional shoes when runners trained with greater mean weekly training distances (shoe*distance interaction: p = 0.036). After greater improvements with minimalist shoes during the initial six weeks of a structured training programme, increasing minimalist shoe use from 35% to 100% over 20 weeks, when runners use their own preferred training programme, did not further improve performance, running economy or alter running biomechanics and lower limb bone mineral density. Minimalist shoes improved plantar flexor strength more than conventional shoes in runners with greater weekly training distances.
Publisher: Informa UK Limited
Date: 2021
Publisher: British Editorial Society of Bone & Joint Surgery
Date: 04-2019
DOI: 10.1302/0301-620X.101B4.BJJ-2018-1240.R1
Abstract: The purpose of this exploratory study was to investigate if the 24-hour activity profile (i.e. waking activities and sleep) objectively measured using wrist-worn accelerometry of patients scheduled for total hip arthroplasty (THA) improves postoperatively. A total of 51 THA patients with a mean age of 64 years (24 to 87) were recruited from a single public hospital. All patients underwent THA using the same surgical approach with the same prosthesis type. The 24-hour activity profiles were captured using wrist-worn accelerometers preoperatively and at 2, 6, 12, and 26 weeks postoperatively. Patient-reported outcomes (Hip Disability and Osteoarthritis Outcome Score (HOOS)) were collected at all timepoints except two weeks postoperatively. Accelerometry data were used to quantify the intensity (sedentary, light, moderate, and vigorous activities) and frequency (bouts) of activity during the day and sleep efficiency. The analysis investigated changes with time and differences between Charnley class. Patients slept or were sedentary for a mean of 19.5 hours/day preoperatively and the 24-hour activity pattern did not improve significantly postoperatively. Outside of sleep, the patients spent their time in sedentary activities for a mean of 620 minutes/day (sd 143) preoperatively and 641 minutes/day (sd 133) six months postoperatively. No significant improvements were observed for light, moderate, and vigorous intensity activities (p = 0.140, p = 0.531, and p = 0.407, respectively). Sleep efficiency was poor ( 85%) at all timepoints. There was no postoperative improvement in sleep efficiency when adjusted for medications (p 0.05). Patient-reported outcome measures showed a significant improvement with time in all domains when compared with preoperative levels. There were no differences with Charnley class at six months postoperatively. However, Charnley class C patients were more sedentary at two weeks postoperatively when compared with Charnley class A patients (p 0.05). There were no further differences between Charnley classifications. This study describes the 24-hour activity profile of THA patients for the first time. Prior to THA, patients in this cohort were inactive and slept poorly. This cohort shows no improvement in 24-hour activity profiles at six months postoperative. Cite this article: Bone Joint J 2019 -B:415–425.
Publisher: Elsevier BV
Date: 03-2014
DOI: 10.1016/J.JBIOMECH.2013.12.033
Abstract: Understanding the kinematics of the carpus is essential to the understanding and treatment of wrist pathologies. However, many of the previous techniques presented are limited by non-functional motion or the interpolation of points from static images at different postures. We present a method that has the capability of replicating the kinematics of the wrist during activities of daily living using a unique mechanical testing system. To quantify the kinematics of the carpal bones, we used bone pin-mounted markers and optical motion capture methods. In this paper, we present a hammering motion as an ex le of an activity of daily living. However, the method can be applied to a wide variety of movements. Our method showed good accuracy (1.0-2.6°) of in vivo movement reproduction in our ex vivo model. Most carpal motion during wrist flexion-extension occurs at the radiocarpal level while in ulnar deviation the motion is more equally shared between radiocarpal and midcarpal joints, and in radial deviation the motion happens mainly at the midcarpal joint. For all rotations, there was more rotation of the midcarpal row relative to the lunate than relative to the scaphoid or triquetrum. For the functional motion studied (hammering), there was more midcarpal motion in wrist extension compared to pure wrist extension while radioulnar deviation patterns were similar to those observed in pure wrist radioulnar deviation. Finally, it was found that for the litudes studied the amount of carpal rotations was proportional to global wrist rotations.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.JBIOMECH.2019.109584
Abstract: Despite the common use of one-handed lifting techniques for activities of daily living, these techniques have received little attention in the biomechanics literature. The braced arm-to-thigh technique (BATT) is a one-handed lifting method in which the dominant hand picks up objects, while the free hand braces the trunk on the ipsilateral thigh. The aim of this study was to compare the BATT to two-handed or unsupported one-handed lifting techniques with loads of 2 and 10 kg, by evaluating trunk motion and spine loading at L4/L5. Twenty healthy participants (30-70 years old) matched in age and sex to 18 participants with low back pain were recruited to the study. A three-axis load cell secured to the distal anterior thigh measured the bracing forces applied by the hand. The OpenSim Lifting Full-Body model was used to estimate trunk kinematics and spinal loading at L4/L5. Linear mixed-effects models were developed to compare trunk angles and L4/L5 moments and forces between lifting techniques. Trunk flexion angles were significantly reduced for the BATT lift compared to one-handed and two-handed stoop lifts (9-20%). However, the BATT also increased asymmetric trunk kinematics and moments at L4/L5. The BATT produced significantly lower moments (28-38%), and compressive (25-32%) and antero-posterior shear (25-45%) forces at L4/L5, compared to unsupported lifting techniques. Bracing the hand on the thigh to support the trunk can substantially reduce low back loading during lifting tasks of 2 to 10 kg.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.JBIOMECH.2016.08.005
Abstract: Estimation of joint reaction forces (JRF) is critical for the understanding of load-related pathologies, such as osteoarthritis (OA). Typically, singular components at discrete time-points are presented without knowledge of their orientation over time. The aim of this study was to develop and demonstrate the utility of a method for the concise and intuitive representation of JRF orientation. A scaled musculoskeletal model of the lower limbs was informed by walking gait data from adults with knee OA (n=10) and healthy controls (C) (n=10). Muscle forces and subsequently JRF were computed. The intersections of the JRF vector and a transverse plane proximal to the joint were computed. The 95% confidence ellipse was computed for these points. This allowed the following metrics to be calculated: the normalised area of the ellipse (A) the ratio of the long and short axes (R) the angle between the long axis of the ellipse and the anterior-posterior axis of the distal segment (α) and the position of the centre of the ellipse relative to the origin of the segment (X
Publisher: Informa UK Limited
Date: 09-2011
Publisher: Springer Science and Business Media LLC
Date: 18-11-2015
DOI: 10.1007/S40279-014-0283-6
Abstract: The effect of footwear on running economy has been investigated in numerous studies. However, no systematic review and meta-analysis has synthesised the available literature and the effect of footwear on running performance is not known. The aim of this systematic review and meta-analysis was to investigate the effect of footwear on running performance and running economy in distance runners, by reviewing controlled trials that compare different footwear conditions or compare footwear with barefoot. The Web of Science, Scopus, MEDLINE, CENTRAL (Cochrane Central Register of Controlled Trials), EMBASE, AMED (Allied and Complementary Medicine), CINAHL and SPORTDiscus databases were searched from inception up until April 2014. Included articles reported on controlled trials that examined the effects of footwear or footwear characteristics (including shoe mass, cushioning, motion control, longitudinal bending stiffness, midsole viscoelasticity, drop height and comfort) on running performance or running economy and were published in a peer-reviewed journal. Of the 1,044 records retrieved, 19 studies were included in the systematic review and 14 studies were included in the meta-analysis. No studies were identified that reported effects on running performance. In idual studies reported significant, but trivial, beneficial effects on running economy for comfortable and stiff-soled shoes [standardised mean difference (SMD) <0.12 P < 0.05), a significant small beneficial effect on running economy for cushioned shoes (SMD = 0.37 P < 0.05) and a significant moderate beneficial effect on running economy for training in minimalist shoes (SMD = 0.79 P < 0.05). Meta-analysis found significant small beneficial effects on running economy for light shoes and barefoot compared with heavy shoes (SMD < 0.34 P < 0.01) and for minimalist shoes compared with conventional shoes (SMD = 0.29 P < 0.01). A significant positive association between shoe mass and metabolic cost of running was identified (P < 0.01). Footwear with a combined shoe mass less than 440 g per pair had no detrimental effect on running economy. Certain models of footwear and footwear characteristics can improve running economy. Future research in footwear performance should include measures of running performance.
Publisher: Springer Science and Business Media LLC
Date: 09-08-2023
DOI: 10.1007/S00068-023-02338-1
Abstract: This scoping review was conducted to summarise the outcome tools reported in the assessment of tibial shaft fractures treated with intramedullary (IM) nailing, with a key focus on knee pain and function, and performance-based outcomes. PubMed and Embase databases were searched on May 31, 2023. All study designs and populations were included, including ex vivo studies without fracture. Studies with only open or intra-articular fractures, or other fracture fixation, were excluded. Reported outcome tools and pertinent study characteristics were extracted and summarised. Of 488 articles identified, 179 met the inclusion criteria. For in vivo studies ( n = 152), there were 13,705 fractures the IM nailing approach not described for 30% of these. There were 133 unique patient outcomes, with a binary assessment of knee pain (29% of studies) and Lysholm score (21%) most common. Only 10/152 (7%) in vivo studies included an objective, performance-based measure of knee function. Fracture union was most frequent (52%) of 81 different clinical outcomes. For ex vivo studies ( n = 29), there were 408 tibias included, with nail insertion location most prevalent (66% of studies) of 34 reported outcomes. The heterogeneity of outcome tools reported limits comparison between studies and the most commonly reported patient outcomes may not be the most appropriate. Future studies should report the IM nailing approach and consider capturing both patient-reported and performance-based outcomes to help inform surgical decision making.
Publisher: Elsevier BV
Date: 02-2020
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.CLINBIOMECH.2017.09.017
Abstract: The design of seating systems to improve comfort and reduce injury would benefit from improved understanding of the deformation and strain patterns in soft tissues, particularly in the gluteal region. Ten healthy men were positioned in a semi-recumbent posture while their pelvic and thigh region was scanned using a wide-bore magnetic resonance imaging (MRI) scanner. Independent measurements of deformation for muscles and fat were taken for the transition from non-weight-bearing to weight-bearing loads in three stages. A weight-bearing load was achieved through having the subject supported by a flat, rigid surface. A non-weight-bearing condition was achieved by removing the support under the left buttock, leaving all soft tissue layers undeformed. An intermediate condition partially relieved the subject's left buttock by lowering the support relative to the pelvis by 20mm, which left the buttock partially deformed. For each of these conditions, the thicknesses of muscle and fat tissues below the ischial tuberosity and the greater trochanter were measured from the MRI data. In this dataset, the greatest soft tissue deformation took place below the ischial tuberosity, with muscles (mean=17.7mm, SD=4.8mm) deforming more than fat tissues (mean=4.3mm, SD=5.6mm). Muscles deformed through both steps of the transition from weight-bearing to non-weight-bearing conditions, while subcutaneous fat deformed little after the first transition from non-weight-bearing to partial-weight-bearing. High inter-subject variability in muscle and fat tissue strains was observed. Our findings highlight the importance of considering inter-subject variability when designing seating systems.
Publisher: Informa UK Limited
Date: 18-06-2015
Publisher: Elsevier BV
Date: 2015
DOI: 10.1016/J.JHSA.2014.09.019
Abstract: To assess carpal kinematics in various ranges of motion in 3 dimensions with respect to lunate morphology. Eight cadaveric wrists (4 type I lunates, 4 type II lunates) were mounted into a customized platform that allowed controlled motion with 6 degrees of freedom. The wrists were moved through flexion-extension (15°-15°) and radioulnar deviation (RUD 20°-20°). The relative motion of the radius, carpus, and third metacarpal were recorded using optical motion capture methods. Clear patterns of carpal motion were identified. Significantly greater motion occurred at the radiocarpal joint during flexion-extension of type I wrist than a type II wrist. The relative contributions of the midcarpal and radiocarpal articulations to movement of the wrist differed between the radial, the central, and the ulnar columns. During wrist flexion and extension, these contributions were determined by the lunate morphology, whereas during RUD, they were determined by the direction of wrist motion. The midcarpal articulations were relatively restricted during flexion and extension of a type II wrist. However, during RUD, the midcarpal joint of the central column became the dominant articulation. This study describes the effect of lunate morphology on 3-dimensional carpal kinematics during wrist flexion and extension. Despite the limited size of the motion arcs tested, the results represent an advance on the current understanding of this topic. Differences in carpal kinematics may explain the effect of lunate morphology on pathological changes within the carpus. Differences in carpal kinematics due to lunate morphology may have implications for the management of certain wrist conditions.
Publisher: Human Kinetics
Date: 02-2021
Publisher: Informa UK Limited
Date: 02-02-2023
DOI: 10.1080/09593985.2022.2034197
Abstract: Determine how mobility changes over 6 months in people unable to walk at 8-weeks post-Acquired Brain Injury (ABI) if there is an association over time between postural alignment and mobility post-ABI and if alignment after ABI becomes closer to healthy alignment over time. Fourteen adults with ABI, evaluated over 6 months, and a reference s le of 30 healthy adults were studied. The primary measure for changes in mobility was the Clinical Outcome Variables Scale (COVS). Secondary measures were sit-to-stand, timed standing holding rails, independent walking speed and number of testing conditions achieved. The Functional Independence Measure (FIM) was scored at rehabilitation admission and discharge. To analyze postural alignment, participants were recorded in sitting and standing, each repeated holding rails, and walking if able. Three-dimensional kinematic data were used to quantify whole-body postural alignment, equal to mean segment displacements from the base of support in the transverse plane. Associations between three-dimensional kinematic alignment scores and COVS scores were calculated using Linear Mixed-Effects Models. Participants made significant improvements in COVS scores, most secondary mobility scores, and FIM scores over time (p ≤ .001). Relationships between increasing COVS scores and decreasing sitting and standing mal-alignment scores were statistically significant. Visual analysis of graphed segment positions indicated that sitting and standing alignment became more similar to healthy alignment over time this was not clear for walking. Improvement in postural alignment may be a factor for improving mobility in people with severe impairments after ABI.
Publisher: Elsevier BV
Date: 05-2011
DOI: 10.1016/J.GAITPOST.2011.03.019
Abstract: In the previous study we have demonstrated that in healthy subjects significant changes in coronal and transverse plane mechanics can be produced by the application of a neutral patella taping technique and a patellar brace. Recently it has also been identified that patients with patellofemoral pain syndrome (PFPS) display alterations in gait in the coronal and transverse planes. This study investigated the effect of patellar bracing and taping on the three-dimensional mechanics of the knee of patellofemoral pain patients during a step descent task. Thirteen patients diagnosed with patellofemoral pain syndrome performed a slow step descent. This was conducted under three randomized conditions: (a) no intervention, (b) neutral patella taping, (c) patellofemoral bracing. A 20cm step was constructed to accommodate an AMTI force platform. Kinematic data were collected using a ten camera infra-red Oqus motion analysis system. Reflective markers were placed on the foot, shank and thigh using the Calibrated Anatomical System Technique (CAST). The coronal plane knee range of motion was significantly reduced with taping (P=0.031) and bracing (P=0.005). The transverse plane showed a significant reduction in the knee range of motion with the brace compared to taping (P=0.032) and no treatment (P=0.046). Patients suffering from patellofemoral pain syndrome demonstrated improved coronal plane and torsional control of the knee during slow step descent following the application of bracing and taping. This study further reinforces the view that coronal and transverse plane mechanics should not be overlooked when studying patellofemoral pain.
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.DRUGALCDEP.2017.05.017
Abstract: Despite evidence that cannabinoid receptors are located in movement-related brain regions (e.g., basal ganglia, cerebral cortex, and cerebellum), and that chronic cannabis use is associated with structural and functional brain changes, little is known about the long-term effect of cannabis use on human movement. The aim of the current study was to investigate balance and walking gait in adults with a history of cannabis use. We hypothesised that cannabis use is associated with subtle changes in gait and balance that are insufficient in magnitude for detection in a clinical setting. Cannabis users (n=22, 24±6years) and non-drug using controls (n=22, 25±8years) completed screening tests, a gait and balance test (with a motion capture system and in-built force platforms), and a clinical neurological examination of movement. Compared to controls, cannabis users exhibited significantly greater peak angular velocity of the knee (396±30 versus 426±50°/second, P=0.039), greater peak elbow flexion (53±12 versus 57±7°, P=0.038) and elbow range of motion (33±13 versus 36±10°, P=0.044), and reduced shoulder flexion (41±19 versus 26±16°, P=0.007) during walking gait. However, balance and neurological parameters did not significantly differ between the groups. The results suggest that history of cannabis use is associated with long-lasting changes in open-chain elements of walking gait, but the magnitude of change is not clinically detectable. Further research is required to investigate if the subtle gait changes observed in this population become more apparent with aging and increased cannabis use.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.INJURY.2015.02.019
Abstract: Osteoporotic tibial plateau fractures (TPFs) are difficult to treat with either open reduction internal fixation (ORIF) or acute total knee arthroplasty (TKA). They have high complication rates, poor outcomes and often fail in the short- to mid-term. We investigated the use of impaction bone grafting (IBG) as an adjunct to stabilise the fracture in a cohort of osteoporotic TPFs. Nine consecutive osteoporotic TPFs were surgically stabilised with ORIF augmented with IBG or with IBG alone (one pure depression fracture) using on average allograft from 2 femoral heads/case (range 1-4 heads or 25-100 cm(3)). The median bone mineral density T-score of the patients was -2.9 (-2.5 to -4.5). All patients were mobilised weight-bearing as tolerated immediately after surgery and had regular follow-up to a minimum of 2 years where functional scores were taken and gait was assessed. Fracture reduction was assessed on plain radiographs and computed tomography (CT) scans maintenance of fracture reduction was monitored using plain radiographs, CT and radiostereometric analysis (RSA). Bone graft remodelling was assessed by comparison of immediate post-operative CT scans with scans at a minimum of 1 year. All surgeries were uneventful. All patients progressed to full weight bearing within 6 weeks of surgery and regained a normal gait by 3 months. Seven fractures healed with a cranio-caudal migration of less than 3mm (range 0-2.6mm using RSA and 0-2mm using CT). Two fractures had an isolated posterolateral fragment depression of 13.5mm and 9 mm, respectively, which did not affect the overall joint alignment or clinical outcomes at short-term follow-up. At latest CT follow-up, on average 51% of the graft area (range 36-70%) had remodelled into new host bone. Impaction bone grafting shows promising results as an adjunct to the surgical stabilisation of osteoporotic TPFs. In this case series the technique provided enough fracture stability for patients to mobilise weight-bearing as tolerated immediately after surgery and achieve full weight-bearing by the sixth postoperative week. There was no failure of fixation and 7 of the 9 cases healed with minimal fracture displacement.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.GAITPOST.2013.09.021
Abstract: Our understanding of age-related changes to foot function during walking has mainly been based on plantar pressure measurements, with little information on differences in foot kinematics between young and older adults. The purpose of this study was to investigate the differences in foot kinematics between young and older adults during walking using a multi-segment foot model. Joint kinematics of the foot and ankle for 20 young (mean age 23.2 years, standard deviation (SD) 3.0) and 20 older adults (mean age 73.2 years, SD 5.1) were quantified during walking with a 12 camera Vicon motion analysis system using a five segment kinematic model. Differences in kinematics were compared between older adults and young adults (preferred and slow walking speeds) using Student's t-tests or if indicated, Mann-Whitney U tests. Effect sizes (Cohen's d) for the differences were also computed. The older adults had a less plantarflexed calcaneus at toe-off (-9.6° vs. -16.1°, d = 1.0, p = <0.001), a smaller sagittal plane range of motion (ROM) of the midfoot (11.9° vs. 14.8°, d = 1.3, p = <0.001) and smaller coronal plane ROM of the metatarsus (3.2° vs. 4.3°, d = 1.1, p = 0.006) compared to the young adults. Walking speed did not influence these differences, as they remained present when groups walked at comparable speeds. The findings of this study indicate that independent of walking speed, older adults exhibit significant differences in foot kinematics compared to younger adults, characterised by less propulsion and reduced mobility of multiple foot segments.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 27-05-2021
Abstract: This article was updated on July 19, 2021, because of a previous error. On page 1172, in the Results section entitled “Sedentary Activity,” the sentence that had read “Postoperatively, 32% at 1 year and 14% at 2 years were sedentary for hours per day.” now reads “Postoperatively, 32% at 1 year and 41% at 2 years were sedentary for hours per day.” Despite marked improvements in self-reported pain, perceived functional ability, and gait function following primary total hip arthroplasty (THA), it remains unclear whether these improvements translate into improved physical activity and sleep behaviors. The aim of this study was to determine the change in 24-hour activity profile (waking activities and sleep) and laboratory-based gait function from preoperatively to 2 years following the THA. Fifty-one patients undergoing primary THA at a single public hospital were recruited. All THAs were performed using a posterior surgical approach with the same prosthesis type. A wrist-worn accelerometer was used to capture 24-hour activity profiles preoperatively and at 1 and 2 years postoperatively. Three-dimensional gait analysis was performed to determine changes in temporospatial and kinematic parameters of the hip and pelvis. Patients showed improvements in all temporospatial and kinematic parameters with time. Preoperatively, patients were sedentary or asleep for a mean time (and standard deviation) of 19.5 ± 2.2 hours per day. This remained unchanged up to 2 years postoperatively (19.6 ± 1.3 hours per day). Sleep efficiency remained suboptimal ( %) at all time points and was worse at 2 years (77% ± 10%) compared with preoperatively (84% ± 5%). More than one-quarter of the s le were sedentary for hours per day at 1 year (32%) and 2 years (41%), which was greater than the preoperative percentage (21%). Patients accumulated their activity performing light activities however, patients performed less light activity at 2 years compared with preoperative levels. No significant differences (p = 0.935) were observed for moderate or vigorous activity across time. Together with improvements in self-reported pain and perceived physical function, patients had significantly improved gait function postoperatively. However, despite the opportunity for patients to be more physically active postoperatively, patients were more sedentary, slept worse, and performed less physical activity at 2 years compared with preoperative levels. Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.
Publisher: Springer Science and Business Media LLC
Date: 30-10-2018
Publisher: Elsevier BV
Date: 06-2013
DOI: 10.1016/J.GAITPOST.2012.11.010
Abstract: Confidence in 3D multi-segment foot models has been limited by a lack of repeatability data, particularly in older populations that may display unique functional foot characteristics. This study aimed to determine the intra and inter-observer repeatability of stance phase kinematic data from a multi-segment foot model described by Leardini et al. [2] in people aged 50 years or older. Twenty healthy adults participated (mean age 65.4 years SD 8.4). A repeated measures study design was used with data collected from four testing sessions on two days from two observers. Intra (within-day and between-day) and inter-observer coefficient of multiple correlations revealed moderate to excellent similarity of stance phase joint range of motion (0.621-0.975). Relative to the joint range of motion (ROM), mean differences (MD) between sessions were highest for the within-day comparison for all planar ROM at the metatarsus-midfoot articulation (sagittal plane ROM 5.2° vs. 3.9°, MD 3.1° coronal plane ROM 3.9 vs. 3.1°, MD 2.3° transverse plane ROM 6.8° vs. 5.16°, MD 3.5°). Consequently, data from the metatarsus-midfoot articulation in the Istituto Ortopedico Rizzoli (IOR) foot model in adults aged over 50 years needs to be considered with respect to the findings of this study.
Publisher: Informa UK Limited
Date: 15-04-2016
DOI: 10.1080/00140139.2016.1158324
Abstract: Load restraint systems in automobile transport utilise tie-down lashings placed over the car's tyres, which are tensioned manually by the operator using a ratchet assembly. This process has been identified as a significant manual handling injury risk. The aim of this study was to gain insight on the current practices associated with tie-down lashings operation, and identify the gaps between current and optimal practice. We approached this with qualitative and quantitative assessments and one numerical simulation to establish: (i) insight into the factors involved in ratcheting (ii) the required tension to hold the car on the trailer and (iii) the tension achieved by drivers in practice and associated joint loads. We identified that the method recommended to the drivers was not used in practice. Drivers instead tensioned the straps to the maximum of their capability, leading to over-tensioning and mechanical overload at the shoulder and elbow. We identified the postures and strategies that resulted in the lowest loads on the upper body during ratcheting (using both hands and performing the task with their full body). This research marks the first step towards the development of a training programme aiming at changing practice to reduce injury risks associated with the operation of tie-down lashings in the automobile transport industry. Practitioner Summary: The study investigated current practice associated with the operation of tie-down lashings through qualitative (interviews) and quantitative (biomechanical analysis) methods. Operators tended to systematically over-tension the lashings and consequently overexert, increasing injury risks.
Publisher: Wiley
Date: 09-01-2018
DOI: 10.1002/ACR.22797
Abstract: Lateral wedge insoles are intended to reduce biomechanical risk factors of medial knee osteoarthritis (OA) progression, such as increased knee joint load however, there has been no definitive consensus on this topic. The aim of this systematic review and meta-analysis was to establish the within-subject effects of lateral wedge insoles on knee joint load in people with medial knee OA during walking. Six databases were searched from inception until February 13, 2015. Included studies reported on the immediate biomechanical effects of lateral wedge insoles during walking in people with medial knee OA. Primary outcomes of interest relating to the biomechanical risk of disease progression were the first and second peak external knee adduction moment (EKAM) and knee adduction angular impulse (KAAI). Eligible studies were pooled using random-effects meta-analysis. Eighteen studies were included with a total of 534 participants. Lateral wedge insoles resulted in a small but statistically significant reduction in the first peak EKAM (standardized mean difference [SMD] -0.19 95% confidence interval [95% CI] -0.23, -0.15) and second peak EKAM (SMD -0.25 95% CI -0.32, -0.19) with a low level of heterogeneity (I(2) = 5% and 30%, respectively). There was a favorable but small reduction in the KAAI with lateral wedge insoles (SMD -0.14 95% CI -0.21, -0.07, I(2) = 31%). Risk of methodologic bias scores (quality index) ranged from 8 to 13 out of 16. Lateral wedge insoles cause small reductions in the EKAM and KAAI during walking in people with medial knee OA. Current evidence demonstrates that lateral wedge insoles appear ineffective at attenuating structural changes in people with medial knee OA as a whole and may be better suited to targeted use in biomechanical phenotypes associated with larger reductions in knee load.
Publisher: Elsevier BV
Date: 03-2022
DOI: 10.1016/J.GAITPOST.2022.01.023
Abstract: In three-dimensional (3D) gait analysis of in iduals requiring a walking frame (walker), acquisition of artefact-free motion and force data is challenging. Without inclusion of handle-reaction forces alongside ground reaction forces, external forces used in musculoskeletal modelling are incomplete. This may increase dynamic inconsistencies between the model and measured motions and forces, thus, uncertainties in estimates of musculoskeletal load. To develop an instrumented walker and evaluate the effects of including handle-reaction forces on residual forces during musculoskeletal modelling. An instrumented walker measuring handle-reaction forces synchronously with motion capture and ground reaction force data was developed. 3D gait analysis was conducted in ten elderly participants recovering from a proximal femur fracture and requiring a walker for ambulation. Joint kinetics and residual forces were calculated between two external load conditions: (1) external loads applied using only force platforms or (2) external loads applied using force platforms and walker handle-reaction forces. Including handle-reaction forces reduced residual forces and improved estimates of musculoskeletal loads of the torso (P = <0.001). A wide instrumented walker measuring handle-reaction forces allows for the gait analysis of in iduals requiring a walker and improves reliability of musculoskeletal dynamics.
Publisher: Elsevier BV
Date: 12-2019
DOI: 10.1016/J.DRUGALCDEP.2019.107595
Abstract: Illicit stimulant use is associated with long-lasting changes in movement and movement-related brain regions. The aim of our study was to investigate the prevalence of movement dysfunction in this population. We hypothesized that prevalence of self-reported movement dysfunction is higher among stimulant users than non-stimulant users. Three groups of adults completed a survey containing questions about demographics, health, drug use, and movement. The groups consisted of ecstasy users with no history of meth hetamine use (ecstasy group, n = 190, 20 ± 3 yrs.), meth hetamine users (meth hetamine group, n = 331, 23 ± 5 yrs.), and non-stimulant users (control group, n = 228, 25 ± 8 yrs.). Movement data was analyzed with logistic regression. In the unadjusted logistic regression model, group had a significant effect on fine hand control, tremor, and voice/speech questions, but not on other movement domain questions. The prevalence of tremor and abnormal fine hand control was significantly higher in the ecstasy and meth hetamine groups than in the control group (p < 0.018), and changes in voice/speech was more prevalent in the ecstasy group than in the control group (p = 0.015). Age and use of cannabis and hallucinogens were confounding variables. However, inspection of chi-square tables suggests that the effect of these parameters on the movement data is likely to be minor. The prevalence of self-reported tremor and changes in fine hand control and voice/speech is significantly higher in stimulant users than in non-stimulant users. Inclusion of these common and noticeable changes in body function may aid public health c aigns that target prevention or harm minimization.
Publisher: Springer Science and Business Media LLC
Date: 08-02-2016
DOI: 10.1007/S10439-016-1560-3
Abstract: Current practices for designing new cushions for seats depend on superficial measurements, such as pressure mapping, which do not provide sufficient information about the condition of sub-dermal tissues. Finite element (FE) modelling offers a unique alternative to integrate assessment of sub-dermal tissue condition into seat/cushion design and development processes. However, the development and validation of such FE models for seated humans requires accurate representation of the anatomy and material properties, which remain challenges that are yet to be addressed. This paper presents the development and validation of a detailed 3D FE model with high anatomical fidelity of the buttock and thigh, for a specific seated subject. The developed model consisted of 28 muscles, the pelvis, sacrum, femur, and one layer of inter-muscular fat, subcutaneous fat and skin. Validation against in vivo measurements from MRI data confirmed that the FE model can simulate the deformation of soft tissues under sitting loads with an accuracy of (mean ± SD) 4.7 ± 4.4 mm. Simulation results showed that the maximum strains (compressive, shear and von-Mises) on muscles (41, 110, 79%) were higher than fat tissues (21, 62, 41%). The muscles that experienced the highest mechanical loads were the gluteus maximus, adductor magnus and muscles in the posterior aspect of the thighs (biceps femoris, semitendinosus and semimembranosus muscles). The developed FE model contributes to the progression towards bio-fidelity in modelling the human body in seated postures by providing insight into the distribution of stresses/strains in in idual muscles and inter-muscular fat in the buttock and thigh of seated in iduals. Industrial applications for the developed FE model include improving the design of office and household furniture, automotive and airplane seats and wheelchairs as well as customisation and assessment of sporting and medical equipment to meet in idual requirements.
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2015
End Date: 2015
Funder: Australian Research Council
View Funded ActivityStart Date: 07-2023
End Date: 06-2027
Amount: $1,091,232.00
Funder: Australian Research Council
View Funded ActivityStart Date: 06-2015
End Date: 12-2018
Amount: $400,000.00
Funder: Australian Research Council
View Funded Activity