ORCID Profile
0000-0002-8969-5181
Current Organisations
Griffith University
,
Queensland Health
,
Griffith University Griffith Health
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Medical Devices | Biomaterials | Biomechanical Engineering | Biomedical Engineering |
Education and Training Systems not elsewhere classified | Expanding Knowledge in Engineering | Expanding Knowledge in the Medical and Health Sciences
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2012
Publisher: Cold Spring Harbor Laboratory
Date: 18-10-2022
DOI: 10.1101/2022.10.14.512218
Abstract: Backed by a century of research and development, Hill-type muscle-tendon models are extensively used for countless applications. Lacking recent reviews, the field of Hill-type modelling is however dense and hard-to-explore, with detrimental consequences on knowledge transmission, inter-study consistency, and innovation. Here we present the first systematic review of the field of Hill-type muscle-tendon modelling. It aims to clarify the literature by detailing its contents and proposing updated terminology and definitions, and discussing the state-of-the-art by identifying the latest advances, current gaps, and potential improvements in modelling muscle properties. To achieve this aim, fifty-five criteria-abiding studies were extracted using a systematic search and their Hill-type models assessed according to a completeness evaluation, which identified the modelled muscle-tendon properties, and a modelling evaluation, which considered the level of validation and reusability of the model, and attention given to its modelling strategy and calibration. It is concluded that most models (1) do not significantly advance the dated gold standards in muscle modelling and do not build upon more recent advances, (2) overlook the importance of parameter identification and tuning, (3) are not strongly validated, and (4) are not reusable in other studies. Besides providing a convenient tool supported by extensive supplementary material for understanding the literature, the results of this review open a discussion on the necessity for global recommendations in Hill-type modelling and more frequent reviews to optimize inter-study consistency, knowledge transmission and model reusability.
Publisher: Springer Science and Business Media LLC
Date: 13-10-2022
DOI: 10.1007/S10237-022-01626-W
Abstract: Neuromusculoskeletal models are a powerful tool to investigate the internal biomechanics of an in idual. However, commonly used neuromusculoskeletal models are generated via linear scaling of generic templates derived from elderly adult anatomies and poorly represent a child, let alone children with a neuromuscular disorder whose musculoskeletal structures and muscle activation patterns are profoundly altered. Model personalization can capture abnormalities and appropriately describe the underlying (altered) biomechanics of an in idual. In this work, we explored the effect of six different levels of neuromusculoskeletal model personalization on estimates of muscle forces and knee joint contact forces to tease out the importance of model personalization for normal and abnormal musculoskeletal structures and muscle activation patterns. For six children, with and without cerebral palsy, generic scaled models were developed and progressively personalized by (1) tuning and calibrating musculotendon units’ parameters, (2) implementing an electromyogram-assisted approach to synthesize muscle activations, and (3) replacing generic anatomies with image-based bony geometries, and physiologically and physically plausible muscle kinematics. Biomechanical simulations of gait were performed in the OpenSim and CEINMS software on ten overground walking trials per participant. A mixed-ANOVA test, with Bonferroni corrections, was conducted to compare all models’ estimates. The model with the highest level of personalization produced the most physiologically plausible estimates. Model personalization is crucial to produce physiologically plausible estimates of internal biomechanical quantities. In particular, personalization of musculoskeletal anatomy and muscle activation patterns had the largest effect overall. Increased research efforts are needed to ease the creation of personalized neuromusculoskeletal models.
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 07-2022
DOI: 10.1016/J.GAITPOST.2022.05.016
Abstract: The tibialis anterior tendon transfer (TATT) is the suggested surgical intervention in the Ponseti method for treatment of dynamic recurrent congenital talipes equinovarus (clubfoot) presenting as hindfoot varus and forefoot supination during the swing phase of gait. The indication for surgery, however, is typically based on visual assessment, which does not sufficiently examine the variability of foot motion in this cohort. The aim of this research was to determine whether subgroups, based on foot model kinematics, existed within a clubfoot cohort being considered for TATT surgery. Sixteen children with recurrent clubfoot that had been previously treated with the Ponseti method and were being considered for tendon transfer surgery were prospectively recruited for this study and were required to attend a pre-surgery data collection session at the Queensland Children's Motion Analysis Service (QCMAS). Data collected included standard Plug-in-Gait (PiG) kinematics and kinetics, Oxford Foot Model (OFM) foot kinematics, and regional plantar loads based on anatomical masking using the integrated kinematic-pressure method. Results of this study identified two clear subgroups within the cohort. One group presented with increased hindfoot inversion across 91 % of the gait cycle. The second group presented with increased hindfoot adduction across 100 % of the gait cycle. Hindfoot adduction was statistically significantly different between the two groups. The identification of these two groups propose a need for further classification of deformity within this cohort and query the appropriateness of this surgical intervention for both presentations.
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.JBIOMECH.2013.11.047
Abstract: The purpose of this study was to determine the muscular contributions to the stepping phase of recovery from forward loss of balance in 5 young and 5 older adults that were able to recover balance in a single step, and 5 older adults that required multiple steps. Forward loss of balance was achieved by releasing participants from a static forward lean angle. All participants were instructed to attempt to recover balance by taking a rapid single step. A scalable anatomical model consisting of 36 degrees-of-freedom was used to compute kinematics and joint moments from motion capture and force plate data. Forces for 94 muscle actuators were computed using static optimisation and induced acceleration analysis was used to compute in idual muscle contributions to net lumbar spine joint, and stepping side hip joint and knee joint accelerations during recovery. Older adults that required multiple recovery steps used a significantly shorter and faster initial recovery step and adopted significantly more trunk flexion throughout recovery compared to the older single steppers. Older multiple steppers also produced significantly more force in the stance side hamstrings, which resulted in significantly higher hamstring induced flexion accelerations at the lumbar spine and extension accelerations at the hip. However since the net joint lumbar spine and hip accelerations remained similar between older multiple steppers and older single steppers, we suggest that the recovery strategy adopted by older multiple steppers was less efficient as well as less effective than for older single steppers.
Publisher: Springer Science and Business Media LLC
Date: 05-11-2019
DOI: 10.1007/S10237-019-01245-Y
Abstract: In biomechanical simulations, generic linearly scaled musculoskeletal anatomies are commonly used to represent children, often neglecting or oversimplifying subject-specific features that may affect model estimates. Inappropriate bone sizing may influence joint angles due to erroneous joint centre identification. Alternatively, subject-specific image-based musculoskeletal models allow for more realistic representations of the skeletal system. To this end, statistical shape modelling (SSM) and morphing techniques may help to reconstruct bones rapidly and accurately. Specifically, the musculoskeletal atlas project (MAP) Client, which employs magnetic resonance imaging (MRI) and/or motion capture data to inform SSM and nonrigid morphing techniques, proved able to accurately reconstruct adult pelvis and femur bones. Nonetheless, to date, the above methods have never been applied to paediatric data. In this study, pelvis, femurs and tibiofibular bones of 18 typically developing children were reconstructed using the MAP Client. Ten different combinations of SSM and morphing techniques, i.e. pipelines, were developed. Generic bone geometries from the gait2392 OpenSim model were linearly scaled for comparisons. Jaccard index, root mean square distance error and Hausdorff distance were computed to quantify reconstruction accuracy. For the pelvis bone, colour maps were produced to identify areas prone to inaccuracies and hip joint centres (HJC) location was compared. Finally, per cent difference between MRI- and MAP-measured left-to-right HJC distances was computed. Pipelines informed by MRI data, alone or in combination with motion capture data, accurately reconstructed paediatric lower limb bones (i.e. Jaccard index > 0.8). Scaled OpenSim geometries provided the least accurate reconstructions. Principal component-based scaling methods produced size-dependent results, which were worse for smaller children.
Publisher: Informa UK Limited
Date: 04-11-2020
DOI: 10.1080/09638288.2020.1839134
Abstract: This qualitative thematic analysis aimed to capture the experiences of children with cerebral palsy (CP) and caregivers who completed an 8-week goal-directed cycling programme, to provide insights on engagement and programme feasibility. Children with CP (6-18 years, Gross Motor Function Classification Scale (GMFCS) levels II-IV) and caregivers completed semi-structured interviews at the end of the training programme. Interview transcripts were coded by two investigators and systematically organised into themes. A third investigator reviewed the final thematic map. 17 interviews were conducted with 29 participants (11 children: 7-14 years). Four themes emerged: facilitators and challenges to programme engagement perceived outcomes the functional-electrical stimulation (FES) cycling experience and previous cycling participation. Engagement was facilitated by the "therapist's connection," "cycling is fun" and "participant driven goal setting," while "getting there" and "time off school" were identified as challenges. Participants positively linked improved physical function to greater independence. The FES-experience was "fun and challenging," and participants had mixed feelings about electrode "stickiness." Previous cycling participation was limited by access to adapted bikes. Children with CP enjoy riding bikes. Facilitators and challenges to engagement were identified that hold practical relevance for clinicians. Environmental and personal factors should be carefully considered when developing future programs, to maximise opportunities for success. Australian New Zealand Clinical Trials Registry - ACTRN12617000644369pIMPLICATIONS FOR REHABILITATIONAdapted cycling is a fun and engaging activity for young people with cerebral palsy.Environmental and personal factors should be carefully considered when prescribing adapted or FES cycling programs to this group.Engagement in adapted and FES-cycling programs can be facilitated by access to loan equipment, a goal-directed focus, and positive therapist-child relationship.Participation in adapted cycling is limited by access to adapted cycling equipment.
Publisher: Elsevier BV
Date: 11-2022
Publisher: Elsevier BV
Date: 06-2016
DOI: 10.1016/J.JBIOMECH.2016.03.052
Abstract: Most clinical gait laboratories use the conventional gait analysis model. This model uses a computational method called Direct Kinematics (DK) to calculate joint kinematics. In contrast, musculoskeletal modelling approaches use Inverse Kinematics (IK) to obtain joint angles. IK allows additional analysis (e.g. muscle-tendon length estimates), which may provide valuable information for clinical decision-making in people with movement disorders. The twofold aims of the current study were: (1) to compare joint kinematics obtained by a clinical DK model (Vicon Plug-in-Gait) with those produced by a widely used IK model (available with the OpenSim distribution), and (2) to evaluate the difference in joint kinematics that can be solely attributed to the different computational methods (DK versus IK), anatomical models and marker sets by using MRI based models. Eight children with cerebral palsy were recruited and presented for gait and MRI data collection sessions. Differences in joint kinematics up to 13° were found between the Plug-in-Gait and the gait 2392 OpenSim model. The majority of these differences (94.4%) were attributed to differences in the anatomical models, which included different anatomical segment frames and joint constraints. Different computational methods (DK versus IK) were responsible for only 2.7% of the differences. We recommend using the same anatomical model for kinematic and musculoskeletal analysis to ensure consistency between the obtained joint angles and musculoskeletal estimates.
Publisher: Elsevier BV
Date: 07-2020
Publisher: Elsevier BV
Date: 09-2017
DOI: 10.1016/J.GAITPOST.2017.06.002
Abstract: Joint kinematics can be calculated by Direct Kinematics (DK), which is used in most clinical gait laboratories, or Inverse Kinematics (IK), which is mainly used for musculoskeletal research. In both approaches, joint centre locations are required to compute joint angles. The hip joint centre (HJC) in DK models can be estimated using predictive or functional methods, while in IK models can be obtained by scaling generic models. The aim of the current study was to systematically investigate the impact of HJC location errors on lower limb joint kinematics of a clinical population using DK and IK approaches. Subject-specific kinematic models of eight children with cerebral palsy were built from magnetic resonance images and used as reference models. HJC was then perturbed in 6mm steps within a 60mm cubic grid, and kinematic waveforms were calculated for the reference and perturbed models. HJC perturbations affected only hip and knee joint kinematics in a DK framework, but all joint angles were affected when using IK. In the DK model, joint constraints increased the sensitivity of joint range-of-motion to HJC location errors. Mean joint angle offsets larger than 5° were observed for both approaches (DK and IK), which were larger than previously reported for healthy adults. In the absence of medical images to identify the HJC, predictive or functional methods with small errors in anterior-posterior and medial-lateral directions and scaling procedures minimizing HJC location errors in the anterior-posterior direction should be chosen to minimize the impact on joint kinematics.
Publisher: Public Library of Science (PLoS)
Date: 16-03-2012
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.GAITPOST.2017.01.017
Abstract: The purpose of this case-control study was to characterise hip joint kinematics and moments during gait in people with mild-to-moderate hip osteoarthritis (OA). Eligible participants were allocated to the hip OA group (n=27) or the age-matched control group (n=26) based on radiographic and symptomatically defined inclusion criteria. Participants walked barefoot along a 10-m walkway at their self-selected gait speed. Trajectories of 43 markers attached to the trunk, pelvis, upper and lower limbs were recorded using a 12-camera motion capture system. Ground reaction force data were simultaneously collected. In iduals in the hip OA group had a 10% higher body mass, 13% slower self-selected walking speed, 10% shorter step length, 2% and 9% longer relative stance and double support duration (% stride) respectively, 41% lower sagittal plane hip range of motion, and 28% and 45% lower peak sagittal and transverse plane hip joint moments respectively during gait compared to controls (p<0.05). The finding that in iduals with mild-to-moderate hip OA experienced less net hip joint loading over a reduced range of hip motion for a longer proportion of the gait cycle when walking at their preferred gait speed suggest that the mechanics of the hip joint are altered in hip OA, and could have implications for disease progression through altered mechano-biological processes within the joint.
Publisher: Springer Science and Business Media LLC
Date: 26-10-2023
Publisher: Elsevier BV
Date: 05-2019
DOI: 10.1016/J.GAITPOST.2019.03.023
Abstract: Leg muscle weakness is a major impairment for in iduals with cerebral palsy (CP) and is related to reduced functional capacity. Evidence is limited regarding the translation of strength improvements following conventional resistance training to improved gait outcomes. Does a combined functional anaerobic and lower limb strength training intervention improve gait kinematics and kinetics in in iduals with CP aged 15-30 years? 17 young adults (21 ± 4 years, 9 males, GMFCS I = 11, II = 6) were randomized to 12 weeks, 3 sessions per week, of high intensity functional anaerobic and progressive resistance training of the lower limbs (n = 8), or a waitlist control group (n = 9). Pre- and post-training outcomes included maximum ankle dorsiflexion angle at foot contact and during stance, gait profile score, ankle and hip power generation during late stance, and the ratio of ankle to hip power generation. There were no between-group differences after the intervention for any kinematic or kinetic gait outcome variable. Within-group analysis revealed an increase in peak ankle power during late stance (0.31 ± 0.28 W·kg We have previously reported increased overground walking capacity, agility and sprint power, in the training group compared to the control group at 12-weeks. These changes in overground measures of functional capacity occurred in the absence of changes in treadmill gait kinematics and kinetics reported here. 12614001217695.
Publisher: Wiley
Date: 2020
DOI: 10.1002/ENG2.12113
Publisher: Springer Science and Business Media LLC
Date: 25-10-2012
Publisher: Avestia Publishing
Date: 08-2018
DOI: 10.11159/ICBES18.124
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.GAITPOST.2018.01.010
Abstract: Altered neural control of movement and musculoskeletal deficiencies are common in children with spastic cerebral palsy (SCP), with muscle weakness and contracture commonly experienced. Both neural and musculoskeletal deficiencies are likely to contribute to abnormal gait, such as equinus gait (toe-walking), in children with SCP. However, it is not known whether the musculoskeletal deficiencies prevent normal gait or if neural control could be altered to achieve normal gait. This study examined the effect of simulated muscle weakness and contracture of the major plantarflexor/dorsiflexor muscles on the neuromuscular requirements for achieving normal walking gait in children. Initial muscle-driven simulations of walking with normal musculoskeletal properties by typically developing children were undertaken. Additional simulations with altered musculoskeletal properties were then undertaken with muscle weakness and contracture simulated by reducing the maximum isometric force and tendon slack length, respectively, of selected muscles. Muscle activations and forces required across all simulations were then compared via waveform analysis. Maintenance of normal gait appeared robust to muscle weakness in isolation, with increased activation of weakened muscles the major compensatory strategy. With muscle contracture, reduced activation of the plantarflexors was required across the mid-portion of stance suggesting a greater contribution from passive forces. Increased activation and force during swing was also required from the tibialis anterior to counteract the increased passive forces from the simulated dorsiflexor muscle contracture. Improvements in plantarflexor and dorsiflexor motor function and muscle strength, concomitant with reductions in plantarflexor muscle stiffness may target the deficits associated with SCP that limit normal gait.
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.EXGER.2015.04.006
Abstract: Falls are prevalent in older adults and are predicted by the maximum forward lean magnitude (MRLM) that can be recovered using a single step. The purpose of this study was to determine the relative contribution of selected neuromuscular and biomechanical variables associated with balance recovery to the MRLM. Forward loss of balance was induced by releasing participants (n=117 community-dwelling older adults) from a static forward lean angle. Participants were instructed to attempt to recover balance by taking a single step. A scalable anatomical model consisting of 36 degrees-of-freedom was used to compute kinematics and joint moments from motion capture and force plate data. Isometric muscle strength at the ankle, knee and hip joints was assessed using a dynamometer. A univariate analysis revealed that lower limb strength measures, step recovery kinematics, and stepping limb kinetics accounted for between 8 and 19%, 3 and 59%, and 3 and 61% of the variance in MRLM respectively. When all variables were entered into a stepwise multiple regression analysis, normalised step length, peak hip extension moment, trunk angle at foot contact, and peak hip flexion power during stepping together accounted for 69% of the variance in MRLM. These findings confirm that successful recovery from forward loss of balance is a whole body control task that requires adequate trunk control and generation of adequate lower limb moments and powers to generate a long and rapid step. Training programmes that specifically target these measures may be effective in improving balance recovery performance and thereby contribute to fall prevention amongst older adults.
Publisher: Wiley
Date: 18-05-2020
DOI: 10.1111/DMCN.14560
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-09-2022
Publisher: SAGE Publications
Date: 02-04-2019
Abstract: The aim of this study was to determine the efficacy of cycling to improve function and reduce activity limitations in children with cerebral palsy the optimal training parameters for improved function and whether improvements in function can be retained. Six databases were searched (until February 2019) and articles were screened in duplicate. Randomized or quasi-randomized controlled trials and pre-post studies were included. Methodological quality was assessed using the Downs and Black scale. Outcomes were reported under the International Classification of Functioning, Disability and Health domains of body functions and activity limitations. Quantitative analyses were completed using RevMan V5.3. A total of 533 articles were identified and 9 studies containing data on 282 participants met full inclusion criteria. Methodological quality ranged from low (14 of 32) to high (28 of 32). Significant improvements were reported for hamstring strength (effect size = 0.77-0.93), cardiorespiratory fitness (effect size = 1.13-1.77), balance (effect size = 1.03-1.29), 3-minute walk test distance (effect size = 1.14) and gross motor function (effect size = 0.91). Meta-analysis suggested that cycling can improve gross motor function (standardized mean difference = 0.35 95% confidence interval = (-0.01, 0.70) Cycling can improve muscle strength, balance and gross motor function in children with cerebral palsy however, optimal training doses are yet to be determined. There was insufficient data to determine whether functional improvements can be retained. Conclusions were limited by small s le sizes, inconsistent outcome measures and a lack of follow-up testing.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Wiley
Date: 18-02-2021
DOI: 10.1111/ANS.16664
Publisher: Elsevier BV
Date: 09-2021
Publisher: Wiley
Date: 28-10-2022
DOI: 10.1111/CEO.14156
Publisher: Elsevier BV
Date: 05-2016
DOI: 10.1016/J.GAITPOST.2016.02.011
Abstract: In motion analysis, pelvis angles are conventionally calculated as the rotations between the pelvis and laboratory reference frame. This approach assumes that the participant's motion is along the anterior-posterior laboratory reference frame axis. When this assumption is violated interpretation of pelvis angels become problematic. In this paper a new approach for calculating pelvis angles based on the rotations between the pelvis and an instantaneous progression reference frame was introduced. At every time-point, the tangent to the trajectory of the midpoint of the pelvis projected into the horizontal plane of the laboratory reference frame was used to define the anterior-posterior axis of the instantaneous progression reference frame. This new approach combined with the rotation-obliquity-tilt rotation sequence was compared to the conventional approach using the rotation-obliquity-tilt and tilt-obliquity-rotation sequences. Four different movement tasks performed by eight healthy adults were analysed. The instantaneous progression reference frame approach was the only approach that showed reliable and anatomically meaningful results for all analysed movement tasks (mean root-mean-square-differences below 5°, differences in pelvis angles at pre-defined gait events below 10°). Both rotation sequences combined with the conventional approach led to unreliable results as soon as the participant's motion was not along the anterior-posterior laboratory axis (mean root-mean-square-differences up to 30°, differences in pelvis angles at pre-defined gait events up to 45°). The instantaneous progression reference frame approach enables the gait analysis community to analysis pelvis angles for movements that do not follow the anterior-posterior axis of the laboratory reference frame.
Publisher: Wiley
Date: 09-08-2020
DOI: 10.1111/DMCN.14648
Publisher: Wiley
Date: 21-12-2016
DOI: 10.1002/WSBM.1368
Abstract: This position paper proposes a modeling pipeline to develop clinically relevant neuromusculoskeletal models to understand and treat complex neurological disorders. Although applicable to a variety of neurological conditions, we provide direct pipeline applicative ex les in the context of cerebral palsy ( CP ). This paper highlights technologies in: (1) patient‐specific segmental rigid body models developed from magnetic resonance imaging for use in inverse kinematics and inverse dynamics pipelines (2) efficient population‐based approaches to derive skeletal models and muscle origins/insertions that are useful for population statistics and consistent creation of continuum models (3) continuum muscle descriptions to account for complex muscle architecture including spatially varying material properties with muscle wrapping (4) muscle and tendon properties specific to CP and (5) neural‐based electromyography‐informed methods for muscle force prediction. This represents a novel modeling pipeline that couples for the first time electromyography extracted features of disrupted neuromuscular behavior with advanced numerical methods for modeling CP ‐specific musculoskeletal morphology and function. The translation of such pipeline to the clinical level will provide a new class of biomarkers that objectively describe the neuromusculoskeletal determinants of pathological locomotion and complement current clinical assessment techniques, which often rely on subjective judgment. WIREs Syst Biol Med 2017, 9:e1368. doi: 10.1002/wsbm.1368 This article is categorized under: Analytical and Computational Methods Computational Methods Models of Systems Properties and Processes Organ, Tissue, and Physiological Models
Publisher: Oxford University Press (OUP)
Date: 10-06-2015
Abstract: a fall occurs when an in idual experiences a loss of balance from which they are unable to recover. Assessment of balance recovery ability in older adults may therefore help to identify in iduals at risk of falls. The purpose of this 12-month prospective study was to assess whether the ability to recover from a forward loss of balance with a single step across a range of lean magnitudes was predictive of falls. two hundred and one community-dwelling older adults, aged 65-90 years, underwent baseline testing of sensori-motor function and balance recovery ability followed by 12-month prospective falls evaluation. Balance recovery ability was defined by whether participants required either single or multiple steps to recover from forward loss of balance from three lean magnitudes, as well as the maximum lean magnitude participants could recover from with a single step. forty-four (22%) participants experienced one or more falls during the follow-up period. Maximal recoverable lean magnitude and use of multiple steps to recover at the 15% body weight (BW) and 25%BW lean magnitudes significantly predicted a future fall (odds ratios 1.08-1.26). The Physiological Profile Assessment, an established tool that assesses variety of sensori-motor aspects of falls risk, was also predictive of falls (Odds ratios 1.22 and 1.27, respectively), whereas age, sex, postural sway and timed up and go were not predictive. reactive stepping behaviour in response to forward loss of balance and physiological profile assessment are independent predictors of a future fall in community-dwelling older adults. Exercise interventions designed to improve reactive stepping behaviour may protect against future falls.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2019
Abstract: Osseous rotational malalignment of the lower limb is widely accepted as a factor contributing to patellofemoral instability, particularly in pediatric patients. Patellar instability occurs when the lateral force vector generated by the quadriceps exceeds the restraints provided by osseous and soft-tissue anatomy. The anatomy and activation of the quadriceps are responsible for the force applied across the patellofemoral joint, which has previously been measured using the quadriceps (Q)-angle. To our knowledge, the contribution of the quadriceps anatomy in generating a force vector in the axial plane has not previously been assessed. The primary aim of this study was to introduce the quadriceps torsion angle, a measure of quadriceps rotational alignment in the juvenile population. The secondary aims of this study were to determine the inter-assessor and intra-assessor reliability of the quadriceps torsion angle in the juvenile population and to investigate whether a large quadriceps torsion angle is a classifier of patellar dislocator group membership in a mixed cohort of patellar dislocators and typically developing controls. Participants between the ages of 8 and 19 years were recruited as either controls or recurrent patellar dislocators. A total of 58 knees in both groups were assessed from magnetic resonance imaging scans of the entire lower limbs. Axial cuts midway between the superior aspect of the femoral head and the articular surface of the medial femoral condyle were used to calculate the proximal reference for the quadriceps torsion angle. The quadriceps torsion angle was defined as the angle between the line connecting the anterior aspect of the sartorius and the junction of the anterior and posterior compartments at the lateral intermuscular septum and the posterior condylar axis line. Inter-assessor reliability was calculated using the intraclass correlation coefficient. The relationship between the quadriceps torsion angle and the femoral torsion was assessed in the entire cohort. These values were compared between the control group and the dislocator group to determine if the raw values or an interplay between the 2 factors played a role in the pathoanatomy of recurrent patellofemoral dislocation. The quadriceps torsion angle was a reproducible assessment in both inter-assessor and intra-assessor reliability analyses. A moderate positive correlation (r = 0.624 p 0.01) was found between the femoral torsion and the quadriceps torsion angle. Although the quadriceps torsion angle was a fair classifier of patellar dislocation group membership, femoral torsion was not. This study has quantified the rotational alignment of the extensor mechanism using the quadriceps torsion angle. The measurement is shown to be reliable and reproducible and a fair classifier of patellofemoral instability. This article introduces an objective measure of soft-tissue rotational malalignment in the pathogenesis of recurrent patellar dislocation.
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.JBIOMECH.2019.07.001
Abstract: Computational knee models that replicate the joint motion are important tools to discern difficult-to-measure functional joint biomechanics. Numerous knee kinematic models of different complexity, with either generic or subject-specific anatomy, have been presented and used to predict three-dimensional tibiofemoral (TFJ) and patellofemoral (PFJ) joint kinematics of cadavers or healthy adults, but not pediatric populations. The aims of this study were: (i) to develop subject-specific TFJ and PFJ kinematic models, with TFJ models having either rigid or extensible ligament constraints, for eight healthy pediatric participants and (ii) to validate the estimated joint and ligament kinematics against in vivo kinematics measured from magnetic resonance imaging (MRI) at four TFJ flexion angles. Three different TFJ models were created from MRIs and used to solve the TFJ kinematics: (i) 5-rigid-link parallel mechanism with rigid surface contact and isometric anterior cruciate (ACL), posterior cruciate (PCL) and medial collateral (MCL) ligaments (ΔL
Publisher: BMJ
Date: 07-2017
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.JBIOMECH.2016.05.033
Abstract: Hip joint contact loads during activities of daily living are not generally considered high enough to cause acute bone or joint injury. However there is some evidence that hip joint loads may be higher in stumble recovery from loss of balance. A common laboratory method used to evaluate balance recovery performance involves suddenly releasing participants from various static forward lean magnitudes (perturbation intensities). Prior studies have shown that when released from the same perturbation intensity, some older adults are able to recover with a single step, whereas others require multiple steps. The main purpose of this study was to use a musculoskeletal model to determine the effect of three balance perturbation intensities and the use of single versus multiple recovery steps on hip joint contact loads during recovery from forward loss of balance in community dwelling older adults (n=76). We also evaluated the association of peak hip contact loads with perturbation intensity, step length and trunk flexion angle at foot contact at each participant׳s maximum recoverable lean angle (MRLA). Peak hip joint contact loads were computed using muscle force estimates obtained using Static Optimisation and increased as lean magnitude was increased and were on average 32% higher for Single Steppers compared to Multiple Steppers. At the MRLA, peak hip contact loads ranged from 4.3 to 12.7 body weights and multiple linear stepwise regression further revealed that initial lean angle, step length and trunk angle at foot contact together explained 27% of the total variance in hip joint contact load. Overall findings indicated that older adults experience peak hip joint contact loads during maximal balance recovery by stepping that in some cases exceeded loads reported to cause mechanical failure of cadaver femurs. While step length and trunk flexion angle are strong predictors of step recovery performance they are at best moderate predictors of peak hip joint loading.
Publisher: Elsevier BV
Date: 11-2009
DOI: 10.1016/J.GAITPOST.2009.08.234
Abstract: Bone sarcomas are the fourth most common cancer in in iduals under 25 years. Limb salvage procedures have become increasingly popular for the treatment of osteosarcomas as they have functional and psychological benefits over traditional utative procedures. The purpose of this paper was to evaluate kinematic and kinetic characteristics of patient's post-limb salvage and examine key predictive factors of gait dysfunction. A retrospective outcome study was undertaken on 20 limb salvage patients (10 females, 10 males) recruited from the Queensland Bone Tumour Registry. Kinematic and kinetic data were collected using a 3D motional analysis system and three force platforms. Loading response knee flexion in the affected lower limb was reduced compared to the unaffected lower limb (P<0.001) and the control group (P<0.001), although, closer examination of results showed two contrasting patterns of knee flexion during loading. Multiple regression analysis showed that muscular integrity (i.e. strength, ROM and residual mass) was the most predictive factor of function following limb salvage surgery. ANOVA showed that patients treated with the Stanmore SIMLES prostheses exhibited superior torque and power production at the ankle during late stance compared to those treated with the Stryker HMRS. In summary, the results showed that limb salvage patients adopted a gait pattern that reduced the moment demand at the knee and hip, suggesting a compensation for pain, reduced stability and/or muscle weakness.
Publisher: Oxford University Press (OUP)
Date: 09-08-2012
Abstract: Older adults compared with young adults have reduced strength and balance recovery ability. The purpose of the present study was to investigate whether age, sex, and/or lower limb strength predicted the stepping strategy used to recover from a forward loss of balance. Ninety-five, community-dwelling, older adults, aged 65-90 years, participated in the study. Loss of balance was induced by releasing participants from a static forward lean. Participants performed four trials at three initial lean magnitudes and were subsequently classified as using a single- or multiple-step strategy. Isometric strength of the ankle, knee, and hip joint flexors and extensors was assessed using a dynamometer. Univariate logistic regression revealed that a unit (ie, 1% body weight [BW] × height) decrease in ankle plantar flexion, knee extension, or hip flexion strength was associated with 1.7-2.5 times increased odds of adopting a multiple-step strategy. Women also had greater odds of requiring a multiple-step recovery strategy at the two greatest lean magnitudes. Forward stepwise logistic regression revealed that hip flexor strength in particular was influential as it was the primary predictor included in the logistic regression models at 20% and 25% BW lean magnitudes. Lower limb muscle weakness, especially of the hip flexors and knee extensors, was associated with increased odds of requiring multiple steps compared with single steps to recover from forward loss of balance across a range of initial lean magnitudes. Improved balance recovery ability might be achieved by targeting these muscle groups in falls prevention programs.
Publisher: Elsevier BV
Date: 2012
DOI: 10.1016/J.JBIOMECH.2011.10.005
Abstract: Experiments designed to assess balance recovery in older adults often involve exposing participants to repeated loss of balance. The purpose of this study was to investigate the adaptive balance recovery response exhibited by older adults following repeated exposure to forward loss of balance induced by releasing participants from a static forward lean angle. Fifty-eight healthy, community-dwelling older adults, aged 65-80 years, participated in the study. Participants were instructed to attempt to recover with a single step and performed four trials at each of three lean angles. Adaptive recovery responses at four events (cable release, toe-off of the stepping foot, foot contact and maximum knee flexion angle following landing in the stepping leg) were quantified for trials performed at the intermediate lean angle using the concept of margin of stability. The antero-posterior and medio-lateral margin of stability were computed as the difference between the velocity-adjusted position of the whole body centre of mass and the corresponding anterior or lateral boundary of the base of support. Across repeated trials adaptations in reactive stepping responses were detected that resulted in improved antero-posterior stability at foot contact and maximum knee flexion angle. Improved antero-posterior stability following repeated trials was explained by more effective control of the whole body centre of mass during the reactive stepping response and not by adjustments in step timing or base of support. The observed adaptations occurred within a single testing session and need to be considered in the design of balance recovery experiments.
Publisher: Springer Science and Business Media LLC
Date: 02-04-2022
DOI: 10.1186/S12887-022-03244-Y
Abstract: There is significant variability in clinical pathways available in the diagnostic assessment of ASD, including the order and timing of allied health assessments in relation to paediatrician consultations. Allied health professionals in first-contact models are increasingly used to improve the timeliness of healthcare access, whilst complementing medical specialty workforce shortages. Anecdotally, the implementation of allied health first-contact models in paediatrics has improved waitlists and timely access to healthcare. However, no rigorous studies have been conducted to evaluate the outcomes of these models. This study aims to determine the impacts of an allied health first-contact model on health service use and costs and patient quality of life and satisfaction. An open, semi-blinded, multi-centre randomised controlled trial in paediatric outpatient clinics at two Australian metropolitan public hospitals. 56 children (0–16 years) fulfilling the inclusion criteria will be randomised to one of two clinical pathways for assessment of ASD: (1) allied health first-contact or (2) medical first-contact model. Cost outcomes will be collected from both health service and family perspectives. Caregiver-reported outcome measures include: Pediatric Quality of Life Inventory (PedsQL), the EuroQOL Five Dimension Youth Version (EQ-5D-Y), the Autism Family Experience Questionnaire (AFEQ) and Measure of Processes of Care. Evidence of improvements in service and consumer centric outcomes will help inform the development and implementation of high-value, evidenced based models of care for the assessment of ASD in children. The findings from this study are expected to contribute to the evidence base around the costs and consequences of allied health first contact models for the assessment of children with ASD in the Australian setting. Findings of this study may help to inform the allocation of health care resources while maintaining, or potentially improving, patient and family quality of life and experience of care. These findings may be useful in informing the wider adoption of these models in Australia and internationally, particularly in healthcare settings where medical specialist shortages exist. Australia and New Zealand Clinical Trials Register (ANZCTR) ACTRN12621001433897 . Registered: 25 th October, 2021.
Publisher: Public Library of Science (PLoS)
Date: 12-04-2018
Publisher: Oxford University Press (OUP)
Date: 12-2021
DOI: 10.1093/GERONI/IGAB046.2568
Abstract: The benefits of Physical Activity (PA) for older adults have been well documented relative to several physiological and neuromuscular factors, but the direct relationship of PA to fall incidence is unclear. In particular, the influence of the intensity and volume of habitual activities of daily living is poorly understood. The purpose of this study was to evaluate the influence of general PA intensity and overall volume on prospective falls in older adults. The PA of 134 participants was recorded using accelerometers (ActiGraph-GT3X+) over 7 consecutive days. Intensity was classified as light, moderate and vigorous by step frequency. The activity of all participants was graded as sedentary to low intensity, no participant exhibited activity in the vigorous category. During the following 12-months, participants maintained a daily falls diary and completed monthly phone calls to monitor fall incidence. Responses were used to categorize participants as fallers or non-fallers. Eighteen participants experienced one or more falls during the 12-month period. There was no statistical difference between fallers and non-fallers in either total step count or the percentage of time spent in sedentary or light PA. While previous reports suggest that many falls occur during light PA, our results do not suggest that greater volumes of low intensity activities alone results in greater fall incidence. However, we suggest this result may be influenced by physical stimuli participants received within the larger overall study design including a session of repeated exposure to forward loss of balance.
Publisher: American Physiological Society
Date: 11-2011
DOI: 10.1152/JAPPLPHYSIOL.00530.2011
Abstract: During human locomotion lower extremity muscle-tendon units undergo cyclic length changes that were previously assumed to be representative of muscle fascicle length changes. Measurements in cats and humans have since revealed that muscle fascicle length changes can be uncoupled from those of the muscle-tendon unit. Ultrasonography is frequently used to estimate fascicle length changes during human locomotion. Fascicle length analysis requires time consuming manual methods that are prone to human error and experimenter bias. To bypass these limitations, we have developed an automatic fascicle tracking method based on the Lucas-Kanade optical flow algorithm with an affine optic flow extension. The aims of this study were to compare gastrocnemius fascicle length changes during locomotion using the automated and manual approaches and to determine the repeatability of the automated approach. Ultrasound was used to examine gastrocnemius fascicle lengths in eight participants walking at 4, 5, 6, and 7 km/h and jogging at 7 km/h on a treadmill. Ground reaction forces and three dimensional kinematics were recorded simultaneously. The level of agreement between methods and the repeatability of the automated method were quantified using the coefficient of multiple correlation (CMC). Regardless of speed, the level of agreement between methods was high, with overall CMC values of 0.90 ± 0.09 (95% CI: 0.86–0.95). Repeatability of the algorithm was also high, with an overall CMC of 0.88 ± 0.08 (95% CI: 0.79–0.96). The automated fascicle tracking method presented here is a robust, reliable, and time-efficient alternative to the manual analysis of muscle fascicle length during gait.
Publisher: Cold Spring Harbor Laboratory
Date: 23-02-2021
DOI: 10.1101/2021.02.22.432159
Abstract: Musculoskeletal (MSK) models based on literature data are meant to represent a generic anatomy and are a popular tool employed by biomechanists to estimate the internal loads occurring in the lower limb joints, such as joint reaction forces (JRFs). However, since these models are normally just linearly scaled to an in idual’s anthropometry, it is unclear how their estimations would be affected by the personalization of key features of the MSK anatomy, one of which is the femoral anteversion angle. How are the lower limb JRF magnitudes computed through a generic MSK model affected by changes in the femoral anteversion? We developed a bone-deformation tool in MATLAB ( rojects/bone_deformity ) and used it to create a set of seven OpenSim models spanning from 2° femoral retroversion to 40° anteversion. We used these models to simulate the gait of an elderly in idual with an instrumented prosthesis implanted at their knee joint (5 th Grand Challenge dataset) and quantified both the changes in JRFs magnitude due to varying the skeletal anatomy and their accuracy against the correspondent in vivo measurements at the knee joint. Hip and knee JRF magnitudes were affected by the femoral anteversion with variations from the unmodified generic model up to 11.7±5.5% at the hip and 42.6±31.0% at the knee joint. The ankle joint was unaffected by the femoral geometry. The MSK models providing the most accurate knee JRFs (root mean squared error: 0.370±0.069 body weight, coefficient of determination: 0.764±0.104, largest peak error: 0.36±0.16 body weight) were those with the femoral anteversion angle closer to that measured on the segmented bone of the in idual. Femoral anteversion substantially affects hip and knee JRFs estimated with generic MSK models, suggesting that personalizing key MSK anatomical features might be necessary for accurate estimation of JRFs with these models.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 04-2009
DOI: 10.1016/J.HUMOV.2009.01.004
Abstract: The effectiveness of dimensionless scaling strategies was assessed using temporal-spatial data collected from an anthropometrically erse group of participants over a range of walking speeds. Video analysis of children (aged 4-15 years, mean=10 years) and adults (18-40 years, mean=25.2 years), each walking at their freely chosen speed, showed adults to take significantly longer strides than children at any given speed (predominately due to their longer lower limbs). Regression analysis of stride length versus walking speed showed that the slopes for adults and children were similar, but that the intercept was significantly higher in adults. Children's data were more scattered compared to those for adults. Plots of relative stride length (L') versus dimensionless speed (u') reduced intra-group variation and eliminated significant differences between adults and children, although subtle differences occurred between children of different ages. These findings support the use of dimensionless scaling in gait analysis, but care should be taken when using dimensionless numbers in relation to children under about 10 years of age due to ineffectiveness of scaling strategies in this group. Normalization for differences in stature using dimensionless scaling was also effective for participants walking at speeds significantly above or below their freely chosen (= 'most efficient') walking speed, suggesting a broad applicability for assessing participants who are unable to walk at their normal walking speed (e.g., participants with endoprostheses, osteoarthritis, or various musculoskeletal problems).
Publisher: Springer Berlin Heidelberg
Date: 2010
Publisher: Wiley
Date: 09-11-2022
DOI: 10.1113/EP090713
Publisher: American Medical Association (AMA)
Date: 03-2022
Publisher: Wiley
Date: 04-2017
DOI: 10.1111/DMCN.13427
Abstract: This study investigates the in vivo function of the medial gastrocnemius and soleus muscle-tendon units (MTU), fascicles, and tendons during walking in children with cerebral palsy (CP) and an equinus gait pattern. Fourteen children with CP (9 males, 5 females mean age 10y 6mo, standard deviation [SD] 2y 11mo GMFCS level I=8, II=6), and 10 typically developing (6 males, 4 females mean age 10y, SD 2y 1mo) undertook full body 3D gait analysis and simultaneous B-mode ultrasound images of the medial gastrocnemius and soleus fascicles during level walking. Fascicle lengths were analysed using a semi-automated tracking algorithm and MTUs using OpenSim. Statistical parametric mapping (two-s le t-test) was used to compare differences between groups (p<0.05). In the CP group medial gastrocnemius fascicles lengthened during mid-stance gait and remained longer into late-stance compared to the typically developing group (p<0.001). CP medial gastrocnemius fascicles shortened less during stance (1.16mm [SD 1.47mm]) compared to the typically developing group (4.48mm [SD 1.94mm], p<0.001). In the CP group the medial gastrocnemius and soleus MTU and tendon were longer during early- and mid-stance (p<0.001). Ankle power during push-off (p=0.015) and positive work (p<0.002) and net work (p<0.001) were significantly lower in the CP group. Eccentric action of the CP medial gastrocnemius muscle fascicles during mid-stance walking is consistent with reduced volume and neuromuscular control of impaired muscle. Reduced ankle push-off power and positive work in the children with CP may be attributed to reduced active medial gastrocnemius fascicle shortening. These findings suggest a reliance on passive force generation for forward propulsion during equinus gait.
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.CMPB.2022.107002
Abstract: Accurate representation of bone shape is important for subject-specific musculoskeletal models as it may influence modelling of joint kinematics, kinetics, and muscle dynamics. Statistical shape modelling is a method to estimate bone shape from minimal information, such as anatomical landmarks, and to avoid the time and cost associated with reconstructing bone shapes from comprehensive medical imaging. Statistical shape models (SSM) of lower limb bones have been developed and validated for adult populations but are not applicable to paediatric populations. This study aimed to develop SSM for paediatric lower limb bones and evaluate their reconstruction accuracy using sparse anatomical landmarks. We created three-dimensional models of 56 femurs, 29 pelves, 56 tibias, 56 fibulas, and 56 patellae through segmentation of magnetic resonance images taken from 29 typically developing children (15 females 13 ± 3.5 years). The SSM for femur, pelvis, tibia, fibula, patella, haunch (i.e., combined femur and pelvis), and shank (i.e., combined tibia and fibula) were generated from manual segmentation of comprehensive magnetic resonance images to describe the shape variance of the cohort. We implemented a leave-one-out cross-validation method wherein SSM were used to reconstruct novel bones (i.e., those not included in SSM generation) using full- (i.e., full segmentation) and sparse- (i.e., anatomical landmarks) input, and then compared these reconstructions against bones segmented from magnetic resonance imaging. Reconstruction performance was evaluated using root mean squared errors (RMSE, mm), Jaccard index (0-1), Dice similarity coefficient (DSC) (0-1), and Hausdorff distance (mm). All results reported in this abstract are mean ± standard deviation. Femurs, pelves, tibias, fibulas, and patellae reconstructed via SSM using full-input had RMSE between 0.89 ± 0.10 mm (patella) and 1.98 ± 0.38 mm (pelvis), Jaccard indices between 0.77 ± 0.03 (pelvis) and 0.90 ± 0.02 (tibia), DSC between 0.87 ± 0.02 (pelvis) and 0.95 ± 0.01 (tibia), and Hausdorff distances between 2.45 ± 0.57 mm (patella) and 9.01 ± 2.36 mm (pelvis). Reconstruction using sparse-input had RMSE ranging from 1.33 ± 0.61 mm (patella) to 3.60 ± 1.05 mm (pelvis), Jaccard indices ranging from 0.59 ± 0.10 (pelvis) to 0.83 ± 0.03 (tibia), DSC ranging from 0.74 ± 0.08 (pelvis) to 0.90 ± 0.02 (tibia), and Hausdorff distances ranging from 3.21 ± 1.19 mm (patella) to 12.85 ± 3.24 mm (pelvis). The SSM of paediatric lower limb bones showed reconstruction accuracy consistent with previously developed SSM and outperformed adult-based SSM when used to reconstruct paediatric bones.
Publisher: Elsevier BV
Date: 04-2021
Publisher: Elsevier BV
Date: 09-2015
DOI: 10.1016/J.GAITPOST.2015.06.189
Abstract: The purpose of this paper was to systematically assess the effect of Oxford Foot Model (OFM) marker misplacement on hindfoot relative to tibia, and forefoot relative to hindfoot kinematic calculations during the stance phase of gait. Marker trajectories were recorded with an 8-camera motion analysis system (Vicon Motion Systems Ltd., UK) and ground reaction forces were recorded from three force platforms (AMTI, USA). A custom built marker cluster consisting of 4 markers in a square arrangement (diagonal distance 2 cm) was used to assess the effect of marker misplacement in the superior, inferior, anterior and posterior direction for the sustentaculum tali (STL), the proximal 1st metatarsal (P1M), distal 5th metatarsal (D5M), proximal 5th metatarsal (P5M) and lateral calcaneus (LCA) markers. In addition manual movement of the heel complex 1 cm superiorly, inferiorly, medially and laterally, and also an alignment error of 10° inversion and 10° eversion was assessed. Clinically meaningful effects of marker misplacement were determined using a threshold indicating the minimal clinically important difference. Misplacement of the heel-wand complex had the most pronounced effect on mean kinematic profiles during the stance phase across all degrees-of-freedom with respect to hindfoot-tibia and forefoot-hindfoot angles. Vertical marker misplacement of the D5M and P5M markers affected the sagittal plane, and to a lesser extent frontal plane, forefoot-hindfoot kinematics. In conclusion, the OFM is highly sensitive to misplacement of the heel-wand complex in all directions and the P5M marker in the vertical direction.
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.RIDD.2016.06.003
Abstract: The aim of this study was to systematically review the current literature to determine the impact of strength training on skeletal muscle morphology and architecture in in iduals aged 4-20 years with spastic type cerebral palsy. A comprehensive search for randomised and non-randomised controlled trials, cohort studies and cross-comparison trials was performed on five electronic databases. Included studies were graded according to level of evidence and assessed for methodological quality using the Downs and Black scale. Quantitative data was analysed using effect sizes. Six of 304 articles met the inclusion criteria. Methodological quality of the included papers ranged from 14 to 19 (out of 32). A large effect was found on muscle cross-sectional area following strength training, with small to moderate effects on muscle volume and thickness. There is preliminary evidence that strength training leads to hypertrophy in children and adolescents with CP. A paucity of studies exist measuring morphological and architectural parameters following strength training in these in iduals. Overall low study methodological quality along with heterogeneous study design, dissimilar outcome measures, and lack of adequate control groups, indicated that care is needed when interpreting the results of these studies in isolation.
Publisher: Public Library of Science (PLoS)
Date: 22-08-2011
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
Publisher: Springer Science and Business Media LLC
Date: 07-06-2021
DOI: 10.1186/S12891-021-04364-9
Abstract: Typical gait is often considered to be highly symmetrical, with gait asymmetries typically associated with pathological gait. Whilst gait symmetry is often expressed in symmetry ratios, measures of symmetry do not provide insight into how these asymmetries affect gait variables. To fully understand changes caused by gait asymmetry, we must first develop a normative database for comparison. Therefore, the aim of this study was to describe normative reference values of regional plantar load and present comparisons with two pathological case studies. A descriptive study of the load transfer of plantar pressures in typically developed children was conducted to develop a baseline for comparison of the effects of gait asymmetry in paediatric clinical populations. Plantar load and 3D kinematic data was collected for 17 typically developed participants with a mean age of 9.4 ± 4.0 years. Two case studies were also included a 10-year-old male with clubfoot and an 8-year-old female with a flatfoot deformity. Data was analysed using a kinematics-pressure integration technique for anatomical masking into 5 regions of interest medial and lateral forefoot, midfoot, and medial and lateral hindfoot. Clear differences between the two case studies and the typical dataset were seen for the load transfer phase of gait. For case study one, lateral bias was seen in the forefoot of the trailing foot across all variables, as well as increases in contact area, force and mean pressure in the lateral hindfoot of the leading foot. For case study two, the forefoot of the trailing foot produced results very similar to the typical dataset across all variables. In the hindfoot of the leading foot, medial bias presents most notably in the force and mean pressure graphs. This study highlights the clinical significance of the load transfer phase of gait, providing meaningful information for intervention planning.
Publisher: Springer Science and Business Media LLC
Date: 30-09-2015
Publisher: Elsevier BV
Date: 12-2012
DOI: 10.1016/J.CLINBIOMECH.2012.07.009
Abstract: Studying recovery responses to loss of balance may help to explain why older adults are susceptible to falls. The purpose of the present study was to assess whether male and female older adults, that use a single or multiple step recovery strategy, differ in the proportion of lower limb strength used and power produced during the stepping phase of balance recovery. Eighty-four community-dwelling older adults (47 men, 37 women) participated in the study. Isometric strength of the ankle, knee and hip joint flexors and extensors was assessed using a dynamometer. Loss of balance was induced by releasing participants from a static forward lean (4 trials at each of 3 forward lean angles). Participants were instructed to recover with a single step and were subsequently classified as using a single or multiple step recovery strategy for each trial. (1) Females were weaker than males and the proportion of females that were able to recover with a single step were lower than for males at each lean magnitude. (2) Multiple compared to single steppers used a significantly higher proportion of their hip extension strength and produced less knee and ankle joint peak power during stepping, at the intermediate lean angle. Strength deficits in female compared to male participants may explain why a lower proportion of female participants were able to recover with a single step. The inability to generate sufficient power in the stepping limb appears to be a limiting factor in single step recovery from forward loss of balance.
Publisher: MDPI AG
Date: 24-09-2019
DOI: 10.3390/MA12193110
Abstract: Unlike subtractive manufacturing technologies, additive manufacturing (AM) can fabricate complex shapes from the macro to the micro scale, thereby allowing the design of patient-specific implants following a biomimetic approach for the reconstruction of complex bone configurations. Nevertheless, factors such as high design variability and changeable customer needs are re-shaping current medical standards and quality control strategies in this sector. Such factors necessitate the urgent formulation of comprehensive AM quality control procedures. To address this need, this study explored and reported on a variety of aspects related to the production and the quality control of additively manufactured patient-specific implants in three different AM companies. The research goal was to develop an integrated quality control procedure based on the synthesis and the adaptation of the best quality control practices with the three examined companies and/or reported in literature. The study resulted in the development of an integrated quality control procedure consisting of 18 distinct gates based on the best identified industry practices and reported literature such as the Food and Drug Administration (FDA) guideline for AM medical devices and American Society for Testing and Materials (ASTM) standards, to name a few. This integrated quality control procedure for patient-specific implants seeks to prepare the AM industry for the inevitable future tightening in related medical regulations. Moreover, this study revealed some critical success factors for companies developing additively manufactured patient-specific implants, including ongoing research and development (R& D) investment, investment in advanced technologies for controlling quality, and fostering a quality improvement organizational culture.
Publisher: Elsevier BV
Date: 02-2020
DOI: 10.1016/J.CLINBIOMECH.2019.12.011
Abstract: Cerebral palsy is a complex neuromuscular disorder that affects the sufferers in multiple different ways. Neuromusculoskeletal models are promising tools that can be used to plan patient-specific treatments for cerebral palsy. However, current neuromusculoskeletal models are typically scaled from generic adult templates that poorly represent paediatric populations. Furthermore, muscle activations are commonly computed via optimisation methods, which may not reproduce co-contraction observed in cerebral palsy. Alternatively, calibrated EMG-informed approaches within OpenSim can capture pathology-related muscle activation abnormalities, possibly enabling more feasible estimations of muscle and joint contact forces. Two identical twin brothers, aged 13, one with unilateral cerebral palsy and the other typically developing, were enrolled in the study. Four neuromusculoskeletal models with increasing subject-specificity were built in OpenSim and CEINMS combining literature findings, experimental motion capture, EMG and MR data for both participants. The physiological and biomechanical validity of each model was assessed by quantifying its ability to track experimental joint moments and muscle excitations. All developed models accurately tracked external joint moments however EMG-informed models better tracked muscle excitations compared to neural solutions generated by static optimisation. Calibrating muscle-tendon unit parameters with EMG data allowed for more physiologically plausible joint contact forces estimates. Further scaling the maximal isometric force of muscles with MR-derived muscle volumes did not affect model predictions. Given their ability to identify atypical joint contact forces profiles and accurately reproduce experimental data, calibrated EMG-informed models should be preferred over generic models using optimisation methods in informing the management of cerebral palsy.
Publisher: Springer Science and Business Media LLC
Date: 04-03-2022
DOI: 10.1038/S41598-022-07541-5
Abstract: Preparing children with cerebral palsy prior to gait analysis may be a challenging and time-intensive task, especially when large number of sensors are involved. Collecting minimum number of electromyograms (EMG) and yet providing adequate information for clinical assessment might improve clinical workflow. The main goal of this study was to develop a method to estimate activation patterns of lower limb muscles from EMG measured from a small set of muscles in children with cerebral palsy. We developed and implemented a muscle synergy extrapolation method able to estimate the full set of lower limbs muscle activation patterns from only three experimentally measured EMG. Specifically, we extracted a set of hybrid muscle synergies from muscle activation patterns of children with cerebral palsy and their healthy counterparts. Next, those muscle synergies were used to estimate activation patterns of muscles, which were not initially measured in children with cerebral palsy. Two best combinations with three (medial gastrocnemius, semi membranous, and vastus lateralis) and four (lateral gastrocnemius, semi membranous, sartorius, and vastus medialis) experimental EMG were able to estimate the full set of 10 muscle activation patterns with mean (± standard deviation) variance accounted for of 79.93 (± 9.64)% and 79.15 (± 6.40)%, respectively, using only three muscle synergies. In conclusion, muscle activation patterns of unmeasured muscles in children with cerebral palsy can be estimated from EMG measured from three to four muscles using our muscle synergy extrapolation method. In the future, the proposed muscle synergy-based method could be employed in gait clinics to minimise the required preparation time.
Publisher: Elsevier BV
Date: 05-2017
DOI: 10.1016/J.GAITPOST.2017.04.001
Abstract: Three-dimensional gait analysis (3DGA) has become a common clinical tool for treatment planning in children with cerebral palsy (CP). Many clinical gait laboratories use the conventional gait analysis model (e.g. Plug-in-Gait model), which uses Direct Kinematics (DK) for joint kinematic calculations, whereas, musculoskeletal models, mainly used for research, use Inverse Kinematics (IK). Musculoskeletal IK models have the advantage of enabling additional analyses which might improve the clinical decision-making in children with CP. Before any new model can be used in a clinical setting, its reliability has to be evaluated and compared to a commonly used clinical gait model (e.g. Plug-in-Gait model) which was the purpose of this study. Two testers performed 3DGA in eleven CP and seven typically developing participants on two occasions. Intra- and inter-tester standard deviations (SD) and standard error of measurement (SEM) were used to compare the reliability of two DK models (Plug-in-Gait and a six degrees-of-freedom model solved using Vicon software) and two IK models (two modifications of 'gait2392' solved using OpenSim). All models showed good reliability (mean SEM of 3.0° over all analysed models and joint angles). Variations in joint kinetics were less in typically developed than in CP participants. The modified 'gait2392' model which included all the joint rotations commonly reported in clinical 3DGA, showed reasonable reliable joint kinematic and kinetic estimates, and allows additional musculoskeletal analysis on surgically adjustable parameters, e.g. muscle-tendon lengths, and, therefore, is a suitable model for clinical gait analysis.
Publisher: Springer Science and Business Media LLC
Date: 19-05-2020
DOI: 10.1038/S41598-020-65257-W
Abstract: Muscle synergies provide a simple description of a complex motor control mechanism. Synergies are extracted from muscle activation patterns using factorisation methods. Despite the availability of several factorisation methods in the literature, the most appropriate method for muscle synergy extraction is currently unknown. In this study, we compared four muscle synergy extraction methods: non-negative matrix factorisation, principal component analysis, independent component analysis, and factor analysis. Probability distribution of muscle activation patterns were compared with the probability distribution of synergy excitation primitives obtained from the four factorisation methods. Muscle synergies extracted using non-negative matrix factorisation best matched the probability distribution of muscle activation patterns across different walking and running speeds. Non-negative matrix factorisation also best tracked changes in muscle activation patterns compared to the other factorisation methods. Our results suggest that non-negative matrix factorisation is the best factorisation method for identifying muscle synergies in dynamic tasks with different levels of muscle contraction.
Publisher: BMJ
Date: 08-2022
DOI: 10.1136/BMJOPEN-2021-057465
Abstract: There is currently no clear indication in the literature regarding a single or double hamstring tendon (single bundle) autograft for anterior cruciate ligament (ACL) reconstruction in the paediatric patient. The primary aim of this single blind randomised controlled trial is to determine whether a single or double hamstring tendon graft ACLR leads to superior clinical outcomes postsurgery in paediatric patients with ACL injury. Single site, prospective, single blind, randomised controlled trial with two parallel treatment arms. 100 patients aged 10–18 years who present with an isolated ACL tear±meniscal injury, verified on MRI, will be randomly allocated to one of the two surgical groups. The primary outcomes will be side-to-side difference in anterior tibial translation and graft failure incidence 12 months postsurgery. Primary and secondary outcomes will also be assessed at 2-year and 5-year postsurgery. Results will be presented in peer-reviewed journals and at international conferences and disseminated to participants and healthcare professionals via newsletters and hospital presentations. This study is approved by the Children’s Health Queensland Hospital and Health Service Human Research Ethics committee. ACTRN12620001170910p Australian New Zealand Clinical Trials Registry.
Publisher: Elsevier BV
Date: 06-2010
DOI: 10.1016/J.JELEKIN.2009.06.001
Abstract: Bone sarcomas are the fourth most common cancer in in iduals under 25 years of age. Limb salvage procedures have become increasingly popular for the treatment of osteosarcomas as they have functional and physiological benefits over traditional utative procedures. The purpose of this study was to assess locomotor patterns post lower limb salvage surgery via electromyographic and energetic measurement techniques on a group of intra-articular knee osteosarcoma patients greater than one year post surgery. A retrospective outcome study was undertaken on 20 limb salvage patients (10 female, 10 male) recruited from the Queensland Bone Tumour Registry. Results showed prolonged activation of rectus femoris and prolonged co-contraction of the rectus femoris and hamstring muscles (p>0.05) in the affected limb of the limb salvage group compared to a control group. Prolonged rectus femoris activation and co-contraction was also evident in the unaffected lower limb suggesting alterations in gait programming within higher neuronal centres. The results are important for the development of rehabilitation programs as they suggest an overall reprogramming of the gait pattern, thereby limiting the impact of conventional strength and stretching interventions.
Publisher: Public Library of Science (PLoS)
Date: 25-10-2017
Publisher: Elsevier BV
Date: 05-2015
DOI: 10.1016/J.CLINBIOMECH.2015.02.005
Abstract: Inaccuracies in locating the three-dimensional position of the hip joint centre affect the calculated hip and knee kinematics, force- and moment-generating capacity of muscles and hip joint mechanics, which can lead to incorrect interpretations and recommendations in gait analysis. Several functional and predictive methods have been developed to estimate the hip joint centre location, and the International Society of Biomechanics recommends a functional approach for use with participants that have adequate range of motion at the hip, and predictive methods in those with insufficient range of motion. The purpose of the current systematic review was to substantiate the International Society of Biomechanics recommendations. This included identifying the most accurate functional and predictive methods, and defining 'adequate' range of motion. A systematic search with broad search terms was performed including five databases. The systematic search yielded to 801 articles, of which 34 papers were included. Eleven different predictive and 13 different functional methods were identified. The results showed that the geometric sphere fit method and Harrington equations are the most accurate functional and predictive approaches respectively that have been evaluated in vivo. In regard to the International Society of Biomechanics recommendations, the geometric sphere fit method should be used in people with sufficient active hip range of motion and the Harrington equations should be used in patients without sufficient hip range of motion. Multi-plane movement trials with at least 60° of flexion-extension and 30° of ab-adduction range of motion are suggested when using functional methods.
Publisher: Elsevier BV
Date: 10-2009
DOI: 10.1016/J.KNEE.2009.02.006
Abstract: Bone sarcomas are the fourth most common cancer in in iduals under 25 years. Limb salvage procedures are popular for the treatment of osteosarcomas as they have functional and physiological benefits over traditional utative procedures. The objective of this study was to apply disease specific measures to a group of intra-articular knee osteosarcoma patients and to evaluate structural and treatment variables predictive of the functional outcome scores. Twenty patients (10 female, 10 male) treated with tumour resection and endoprosthetic knee arthroplasty took part in the study. The Musculoskeletal Tumour Society (MSTS) rating scale and the Toronto Extremity Salvage Score (TESS) were used to assess impairment and disability respectively. Impairment was recorded as 83% and disability was recorded as 86% suggesting moderate to high function following limb salvage surgery. Task difficulty was shown to increase for activities requiring large knee flexion angles, presumably due to increased patellofemoral forces. Bivariate correlations revealed that loss of quadriceps musculature, knee extension strength and knee flexion range of motion were parameters moderately associated with the assessment instruments. ANOVA revealed no significant differences in impairment (P=0.962) or disability (P=0.411) between the differing types of prostheses. In conclusion clinicians and therapists should emphasise restoration of post-surgical range of motion and strength in order to enhance functional recovery.
Publisher: Elsevier BV
Date: 06-2021
Publisher: Elsevier BV
Date: 10-2013
DOI: 10.1016/J.JELEKIN.2013.05.012
Abstract: In response to a balance disturbance, older in iduals often require multiple steps to prevent a fall. Reliance on multiple steps to recover balance is predictive of a future fall, so studies should determine the mechanisms underlying differences between older adults who can and cannot recover balance with a single step. This study compared neural activation parameters of the major leg muscles during balance recovery from a sudden forward loss of balance in older in iduals capable of recovering with a single step and those who required multiple steps to regain balance. Eighty-one healthy, community dwelling adults aged 70±3 participated. Loss of balance was induced by releasing participants from a static forward lean. Participants performed four trials at three initial lean magnitudes and were subsequently classified as single or multiple steppers. Although step length was shorter in multiple compared to single steppers (F=9.64 p=0.02), no significant differences were found between groups in EMG onset time in the step limb muscles (F=0.033-0.769 p=0.478-0.967). However, peak EMG normalised to values obtained during maximal voluntary contraction was significantly higher in single steppers in 6 of the 7 stepping limb muscles (F=1.054-4.167 p=0.045-0.024). These data suggest that compared to multiple steppers, single steppers recruit a larger proportion of the available motor unit pool during balance recovery. Thus, modulation of EMG litude plays a larger role in balance recovery than EMG timing in this context.
Publisher: BMJ
Date: 06-2019
DOI: 10.1136/BMJOPEN-2018-024881
Abstract: Children with cerebral palsy (CP) experience declines in gross motor ability as they transition from childhood to adolescence, which can result in the loss of ability to perform sit-to-stand transfers, ambulate or participate in leisure activities such as cycling. Functional electrical stimulation (FES) cycling is a novel technology that may provide opportunities for children with CP to strengthen their lower limbs, improve functional independence and increase physical activity participation. The proposed randomised controlled trial will test the efficacy of a training package of FES cycling, adapted cycling and goal-directed functional training to usual care in children with CP who are susceptible to functional declines. Forty children with CP (20 per group), aged 6–8 years and classified as Gross Motor Function Classification System (GMFCS) levels II–IV will be recruited across South East Queensland. Participants will be randomised to either an immediate intervention group, who will undertake 8 weeks of training, or a waitlist control group. The training group will attend two 1 hour sessions per week with a physiotherapist, consisting of FES cycling and goal-directed, functional exercises and a 1 hour home exercise programme per week, consisting of recreational cycling. Primary outcomes will be the gross motor function measure and Canadian occupational performance measure, and secondary outcomes will include the five times sit-to-stand test, habitual physical activity (accelerometry), power output during cycling and Participation and Environment Measure-Children and Youth. Outcomes will be assessed at baseline, postintervention (8 weeks) and 8 weeks following the intervention (retention). Ethical approval has been obtained from Griffith University (2018/037) and the Children’s Health Queensland Hospital and Health Service (CHQHHS) Human Research Ethics Committee (HREC/17/QRCH/88). Site-specific approval was obtained from CHQHHS research governance (SSA/17/QRCH/145). Results from this trial will be disseminated via publication in relevant peer-reviewed journals. ACTRN12617000644369p.
Publisher: Human Kinetics
Date: 10-2023
Abstract: Spasticity is a common impairment within pediatric neuromusculoskeletal disorders. How spasticity contributes to gait deviations is important for treatment selection. Our aim was to evaluate the pathophysiological mechanisms underlying gait deviations seen in children with spasticity, using predictive simulations. A cluster analysis was performed to extract distinct gait patterns from experimental gait data of 17 children with spasticity to be used as comparative validation data. A forward dynamic simulation framework was employed to predict gait with either velocity- or force-based hyperreflexia. This framework entailed a generic musculoskeletal model controlled by reflexes and supraspinal drive, governed by a multiobjective cost function. Hyperreflexia values were optimized to enable the simulated gait to best match experimental gait patterns. Three experimental gait patterns were extracted: (1) increased knee flexion, (2) increased ankle plantar flexion, and (3) increased knee flexion and ankle plantar flexion when compared with typical gait. Overall, velocity-based hyperreflexia outperformed force-based hyperreflexia. The first gait pattern could mostly be explained by rectus femoris and hamstrings velocity-based hyperreflexia, the second by gastrocnemius velocity-based hyperreflexia, and the third by gastrocnemius, soleus, and hamstrings velocity-based hyperreflexia. This study shows how velocity-based hyperreflexia from specific muscles contributes to different spastic gait patterns, which may help in providing targeted treatment.
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JBIOMECH.2019.05.026
Abstract: Neuro-musculoskeletal modelling can provide insight into the aberrant muscle function during walking in those suffering cerebral palsy (CP). However, such modelling employs optimization to estimate muscle activation that may not account for disturbed motor control and muscle weakness in CP. This study evaluated different forms of neuro-musculoskeletal model personalization and optimization to estimate musculotendon forces during gait of nine children with CP (GMFCS I-II) and nine typically developing (TD) children. Data collection included 3D-kinematics, ground reaction forces, and electromyography (EMG) of eight lower limb muscles. Four different optimization methods estimated muscle activation and musculotendon forces of a scaled-generic musculoskeletal model for each child walking, i.e. (i) static optimization that minimized summed-excitation squared (ii) static optimization with maximum isometric muscle forces scaled to body mass (iii) an EMG-assisted approach using optimization to minimize summed-excitation squared while reducing tracking errors of experimental EMG-linear envelopes and joint moments and (iv) EMG-assisted with musculotendon model parameters first personalized by calibration. Both static optimization approaches showed a relatively low model performance compared to EMG envelopes. EMG-assisted approaches performed much better, especially in CP, with only a minor mismatch in joint moments. Calibration did not affect model performance significantly, however it did affect musculotendon forces, especially in CP. A model more consistent with experimental measures is more likely to yield more physiologically representative results. Therefore, this study highlights the importance of calibrated EMG-assisted modelling when estimating musculotendon forces in TD children and even more so in children with CP.
Publisher: Elsevier BV
Date: 07-2021
Publisher: Royal Society of Chemistry (RSC)
Date: 2022
DOI: 10.1039/D2RA00642A
Abstract: The antimony( iii ) complex of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) has been prepared and its exceptionally low stability observed.
Publisher: Springer Science and Business Media LLC
Date: 29-01-2022
DOI: 10.1007/S00455-022-10410-Y
Abstract: Use of machine learning to accurately detect aspirating swallowing sounds in children is an evolving field. Previously reported classifiers for the detection of aspirating swallowing sounds in children have reported sensitivities between 79 and 89%. This study aimed to investigate the accuracy of using an automatic speaker recognition approach to differentiate between normal and aspirating swallowing sounds recorded from digital cervical auscultation in children. We analysed 106 normal swallows from 23 healthy children (median 13 months 52.1% male) and 18 aspirating swallows from 18 children (median 10.5 months 61.1% male) who underwent concurrent videofluoroscopic swallow studies with digital cervical auscultation. All swallowing sounds were on thin fluids. A support vector machine classifier with a polynomial kernel was trained on feature vectors that comprised the mean and standard deviation of spectral subband centroids extracted from each swallowing sound in the training set. The trained support vector machine was then used to classify swallowing sounds in the test set. We found high accuracy in the differentiation of aspirating and normal swallowing sounds with 98% overall accuracy. Sensitivity for the detection of aspiration and normal swallowing sounds were 89% and 100%, respectively. There were consistent differences in time, power spectral density and spectral subband centroid features between aspirating and normal swallowing sounds in children. This study provides preliminary research evidence that aspirating and normal swallowing sounds in children can be differentiated accurately using machine learning techniques.
Publisher: Elsevier BV
Date: 03-2017
DOI: 10.1016/J.GAITPOST.2017.01.023
Abstract: In human motion analysis predictive or functional methods are used to estimate the location of the hip joint centre (HJC). It has been shown that the Harrington regression equations (HRE) and geometric sphere fit (GSF) method are the most accurate predictive and functional methods, respectively. To date, the comparative reliability of both approaches has not been assessed. The aims of this study were to (1) compare the reliability of the HRE and the GSF methods, (2) analyse the impact of the number of thigh markers used in the GSF method on the reliability, (3) evaluate how alterations to the movements that comprise the functional trials impact HJC estimations using the GSF method, and (4) assess the influence of the initial guess in the GSF method on the HJC estimation. Fourteen healthy adults were tested on two occasions using a three-dimensional motion capturing system. Skin surface marker positions were acquired while participants performed quite stance, perturbed and non-perturbed functional trials, and walking trials. Results showed that the HRE were more reliable in locating the HJC than the GSF method. However, comparison of inter-session hip kinematics during gait did not show any significant difference between the approaches. Different initial guesses in the GSF method did not result in significant differences in the final HJC location. The GSF method was sensitive to the functional trial performance and therefore it is important to standardize the functional trial performance to ensure a repeatable estimate of the HJC when using the GSF method.
Publisher: SAGE Publications
Date: 29-05-2019
Abstract: Background: Chronic recurrent multifocal osteomyelitis (CRMO) is a rare autoinflammatory condition characterized by bone pain and swelling, secondary to sterile bone osteolytic lesions. Estimated incidence is 1:1 000 000, with ~2% involving the hand. We present a case series of CRMO of the hand and review the available literature, with the aim of educating and raising awareness of this condition. Methods: A retrospective chart review was conducted for all patients presenting to the institution diagnosed with CRMO involving the hands. Subsequently, a literature review was performed. Results/Case Series: Three cases of CRMO of the hand were identified. Age ranged from 20 months to 6 years, with 1 female. Time from presentation to diagnosis ranged from 3 to 15 months. Two had a single lesion, with the remaining patient having a second lesion on full-body magnetic resonance imaging (MRI). Three lesions involved phalanges, and one involved a metacarpal. Two received antibiotics without improvement prior to diagnosis. After diagnosis of CRMO, two received intravenous pamidronate. They both later showed improvement on MRI. Conclusion: CRMO is a rare disease with scarce literature to guide management. We present a series of CRMO specifically of the hand. The cases educate key stakeholders, raise awareness of the diagnosis, and illustrate challenging aspects of managing these patients. This includes the special functional and anatomical consideration essential in managing cases involving the hand.
Publisher: American Physiological Society
Date: 15-03-2012
DOI: 10.1152/JAPPLPHYSIOL.01402.2011
Abstract: Human movement requires an ongoing, finely tuned interaction between muscular and tendinous tissues, so changes in the properties of either tissue could have important functional consequences. One condition that alters the functional demands placed on lower limb muscle-tendon units is the use of high-heeled shoes (HH), which force the foot into a plantarflexed position. Long-term HH use has been found to shorten medial gastrocnemius muscle fascicles and increase Achilles tendon stiffness, but the consequences of these changes for locomotor muscle-tendon function are unknown. This study examined the effects of habitual HH use on the neuromechanical behavior of triceps surae muscles during walking. The study population consisted of 9 habitual high heel wearers who had worn shoes with a minimum heel height of 5 cm at least 40 h/wk for a minimum of 2 yr, and 10 control participants who habitually wore heels for less than 10 h/wk. Participants walked at a self-selected speed over level ground while ground reaction forces, ankle and knee joint kinematics, lower limb muscle activity, and gastrocnemius fascicle length data were acquired. In long-term HH wearers, walking in HH resulted in substantial increases in muscle fascicle strains and muscle activation during the stance phase compared with barefoot walking. The results suggest that long-term high heel use may compromise muscle efficiency in walking and are consistent with reports that HH wearers often experience discomfort and muscle fatigue. Long-term HH use may also increase the risk of strain injuries.
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.GAITPOST.2010.11.017
Abstract: The purposes of this study were to quantify stability during recovery from forward loss of balance in young and older adults, older single steppers (OSS) and older multiple steppers (OMS), and to identify the biomechanical factors associated with stability during balance recovery. Forward loss of balance was achieved by releasing participants from a static forward lean angle. Participants regained balance by taking one or more rapid steps. Stability was quantified using the margin of stability (MoS), which was computed as the anterio-posterior distance between the forward boundary of the base-of-support and the vertical projection of the velocity adjusted centre of mass. MoS at foot contact and at maximal knee joint flexion angle following foot contact (KJ(MAX)) were smaller in older compared to young adults, and in OMS compared to OSS. Compared to young adults, older adults exhibited a shorter recovery step length, greater trunk flexion angles and exhibited smaller peak knee flexion angles. Trunk flexion angle at foot contact (r=-0.55) and step length (r=0.54) were significantly correlated with MoS at foot contact and together accounted for 51% of the variance in MoS at foot contact. MoS at foot contact was significantly correlated with MoS at KJ(MAX) (r=0.88) and together with peak knee flexion angle during the landing phase (r=0.60) and peak knee extension moment during the landing phase (r=0.47) accounted for 84% of the variance in MoS at KJ(MAX). Overall findings suggest that stability in the first step is lower for older compared to young adults and for multiple compared to single steppers, and that spatial-temporal, kinematic and kinetic factors are associated with stability during recovery from forward loss of balance.
Publisher: Elsevier BV
Date: 09-2020
Publisher: Human Kinetics
Date: 10-2017
Abstract: Gait analysis together with musculoskeletal modeling is widely used for research. In the absence of medical images, surface marker locations are used to scale a generic model to the in idual’s anthropometry. Studies evaluating the accuracy and reliability of different scaling approaches in a pediatric and/or clinical population have not yet been conducted and, therefore, formed the aim of this study. Magnetic resonance images (MRI) and motion capture data were collected from 12 participants with cerebral palsy and 6 typically developed participants. Accuracy was assessed by comparing the scaled model’s segment measures to the corresponding MRI measures, whereas reliability was assessed by comparing the model’s segments scaled with the experimental marker locations from the first and second motion capture session. The inclusion of joint centers into the scaling process significantly increased the accuracy of thigh and shank segment length estimates compared to scaling with markers alone. Pelvis scaling approaches which included the pelvis depth measure led to the highest errors compared to the MRI measures. Reliability was similar between scaling approaches with mean ICC of 0.97. The pelvis should be scaled using pelvic width and height and the thigh and shank segment should be scaled using the proximal and distal joint centers.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.GAITPOST.2014.05.066
Abstract: The purpose of this study was to systematically review the current literature to determine the effect of a femoral derotation osteotomy (FDRO) on hip and pelvic rotation kinematics during gait compared to no intervention in children with spastic cerebral palsy (CP). We performed a systematic search for prospective and retrospective cohort studies of children with CP, who were treated with a FDRO, and were assessed with pre and post surgery three-dimensional gait analysis. Medline, CINAHL, EMBASE, the Cochrane Library and Web of Science were searched up to December 2013. Data sources were prospective and retrospective studies. Mean differences were calculated on pooled data for both pelvic and hip rotation kinematics. Thirteen of 196 articles met the inclusion criteria (5 prospective, 8 retrospective). All included studies were of sufficient quality for meta-analysis as assessed using a customised version of the STROBE checklist. Meta-analysis showed that FDRO significantly reduced pelvic retraction by 9.0 degrees and hip internal rotation by 17.6 degrees in participants with unilateral CP involvement and hip internal rotation by 14.3 degrees in participants with bilateral CP involvement. Pelvic symmetry in children with unilateral spastic CP is significantly improved by FDRO. Patients with bilateral involvement do not improve their transverse plane pelvic rotation profiles during gait as a result to FDRO, although this result should be interpreted with caution due to the heterogeneous nature of these participants and of the methods used in the studies assessed.
Start Date: 09-2019
End Date: 07-2025
Amount: $4,000,000.00
Funder: Australian Research Council
View Funded Activity