ORCID Profile
0000-0002-8866-0913
Current Organisation
University of Western Australia
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.
Artificial Intelligence and Image Processing not elsewhere classified | Biomechanical Engineering | Computer Vision | Artificial Intelligence and Image Processing
Expanding Knowledge in the Physical Sciences | Expanding Knowledge in Engineering | Expanding Knowledge in Technology |
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JBIOMECH.2016.10.006
Abstract: The aims of this study were to: (i) establish a new criterion method to validate inertia tensor estimates by setting the experimental angular velocity data of an airborne objects as ground truth against simulations run with the estimated tensors, and (ii) test the sensitivity of the simulations to changes in the inertia tensor components. A rigid steel cylinder was covered with reflective kinematic markers and projected through a calibrated motion capture volume. Simulations of the airborne motion were run with two models, using inertia tensor estimated with geometric formula or the compound pendulum technique. The deviation angles between experimental (ground truth) and simulated angular velocity vectors and the root mean squared deviation angle were computed for every simulation. Monte Carlo analyses were performed to assess the sensitivity of simulations to changes in magnitude of principal moments of inertia within ±10% and to changes in orientation of principal axes of inertia within ±10° (of the geometric-based inertia tensor). Root mean squared deviation angles ranged between 2.9° and 4.3° for the inertia tensor estimated geometrically, and between 11.7° and 15.2° for the compound pendulum values. Errors up to 10% in magnitude of principal moments of inertia yielded root mean squared deviation angles ranging between 3.2° and 6.6°, and between 5.5° and 7.9° when lumped with errors of 10° in principal axes of inertia orientation. The proposed technique can effectively validate inertia tensors from novel estimation methods of body segment inertial parameter. Principal axes of inertia orientation should not be neglected when modelling human/animal mechanics.
Publisher: Springer Science and Business Media LLC
Date: 17-03-2018
DOI: 10.1007/S11517-018-1802-7
Abstract: An understanding of athlete ground reaction forces and moments (GRF/Ms) facilitates the biomechanist's downstream calculation of net joint forces and moments, and associated injury risk. Historically, force platforms used to collect kinetic data are housed within laboratory settings and are not suitable for field-based installation. Given that Newton's Second Law clearly describes the relationship between a body's mass, acceleration, and resultant force, is it possible that marker-based motion capture can represent these parameters sufficiently enough to estimate GRF/Ms, and thereby minimize our reliance on surface embedded force platforms? Specifically, can we successfully use partial least squares (PLS) regression to learn the relationship between motion capture and GRF/Ms data? In total, we analyzed 11 PLS methods and achieved average correlation coefficients of 0.9804 for GRFs and 0.9143 for GRMs. Our results demonstrate the feasibility of predicting accurate GRF/Ms from raw motion capture trajectories in real-time, overcoming what has been a significant barrier to non-invasive collection of such data. In applied biomechanics research, this outcome has the potential to revolutionize athlete performance enhancement and injury prevention. Graphical Abstract Using data science to model high-fidelity motion and force plate data frees biomechanists from the laboratory.
Publisher: Informa UK Limited
Date: 08-06-2022
DOI: 10.1080/02640414.2022.2086520
Abstract: The purpose of this study was to investigate the behaviour of physiological load measures as well as ground reaction forces (GRF) and acceleration load during a prolonged running task that simulated the running demands of an intermittent team sport. Nineteen males completed a maximal aerobic fitness test and an extended running protocol across two sessions. Participants wore a portable metabolic system, and four inertial measurement units (IMU), one on each foot, the lower back and upper back. GRF were measured via an instrumented treadmill. Change in metabolic, IMU and GRF variables across five blocks during the running protocol were assessed using a one-way repeated measures ANOVA. The running protocol elicited large increases in heart rate and oxygen consumption over time. No statistically significant changes in any peak impact accelerations were observed. Resultant acceleration area under the curve (AUC) increased at the lower and upper back locations but was unchanged at the foot. GRF active peak but not impact peak increased during the prolonged run. The results of this study indicate that the effect of an extended running task on IMU measures of external mechanical load is manifested in the upper body, and is effectively measured by AUC.
Publisher: SPIE
Date: 04-02-2010
DOI: 10.1117/12.840153
Publisher: Elsevier BV
Date: 08-2003
DOI: 10.1016/S0021-9290(03)00087-3
Abstract: Repeatability of traditional kinematic and kinetic models is affected by the ability to accurately locate anatomical landmarks (ALs) to define joint centres and anatomical coordinate systems. Numerical methods that define joint centres and axes of rotation independent of ALs may also improve the repeatability of kinematic and kinetic data. The purpose of this paper was to compare the repeatability of gait data obtained from two models, one based on ALs (AL model), and the other incorporating a functional method to define hip joint centres and a mean helical axis to define knee joint flexion/extension axes (FUN model). A foot calibration rig was also developed to define the foot segment independent of ALs. The FUN model produced slightly more repeatable hip and knee joint kinematic and kinetic data than the AL model, with the advantage of not having to accurately locate ALs. Repeatability of the models was similar comparing within-tester sessions to between-tester sessions. The FUN model may also produce more repeatable data than the AL model in subject populations where location of ALs is difficult. The foot calibration rig employed in both the AL and FUN model provided an easy alternative to define the foot segment and obtain repeatable data, without accurately locating ALs on the foot.
Publisher: Informa UK Limited
Date: 31-07-2020
Publisher: Springer Science and Business Media LLC
Date: 13-03-2009
DOI: 10.1007/S11517-009-0467-7
Abstract: This study aimed to find the most appropriate marker location, or combination thereof, for the centre of the humeral head (Wang et al. in J Biomech 31: 899-908, 1998) location representation during humeral motion. Ten male participants underwent three MRI scans in three different humeral postures. Seven technical coordinate systems (TCS) were defined from various combinations of an acromion, distal upper arm and proximal upper arm clusters of markers in a custom Matlab program. The CHH location was transformed between postures and then compared with the original MRI CHH location. The results demonstrated that following the performance of two near 180 degrees humeral elevations, a combined acromion TCS and proximal upper arm TCS produced an average error of 23 +/- 9 mm, and 18 +/- 4 mm, which was significantly smaller (p < 0.01) than any other TCS. A combination of acromion and proximal upper arm TCSs should therefore be used to reference the CHH location when analysing movements incorporating large ranges of shoulder motion.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2014
Publisher: Elsevier BV
Date: 2014
Publisher: Wiley
Date: 03-2016
DOI: 10.1111/SMS.12668
Abstract: Sidestepping in response to unplanned stimuli is a high-risk maneuver for anterior cruciate ligament (ACL) injuries. Yet, differences in body reorientation strategies between high- and low-level soccer players prior to sidestepping in response to quasi-game-realistic vs non-game-realistic stimuli, remain unknown. Fifteen high-level (semi-professional) and 15 low-level (amateur) soccer players responded to a quasi-game-realistic one-defender scenario (1DS) and two-defender scenario (2DS), and non-game-realistic arrow-planned condition (AP) and arrow-unplanned condition (AUNP). The AP, 1DS, 2DS to AUNP represented increasing time constraints to sidestep. Selected biomechanics from the penultimate step to foot-off were assessed using a mixed-model (stimuli × skill) ANOVA (P < 0.05). Step length decreased in the defender scenarios compared with the arrow conditions. Support foot placement increased laterally, away from mid-pelvis, with increasing temporal constraints. Greater trunk lateral flexion in the 1DS, 2DS, and AUNP has been associated with ACL injury onsets. Higher level players pushed off closer to their pelvic midline at initial foot contact in the 2DS especially. Higher level perception of game-realistic visual information could have contributed to this safer neuromuscular strategy that, when understood better, could potentially be trained in lower level players to reduce ACL injury risk associated with dangerous sidestepping postures.
Publisher: Informa UK Limited
Date: 09-2009
DOI: 10.1080/14763140903229476
Abstract: This study sought to identify kinematic differences in finger-spin bowling actions required to generate variations in ball speed and spin between different playing groups. A 12-camera Vicon system recorded the off-spin bowling actions of six elite and 13 high-performance spin bowlers, and the "doosra" actions of four elite and two high-performance players. Forearm abduction and fixed elbow flexion in the bowling arm were higher for the elite players compared with the high-performance players. The elite bowlers when compared with the high-performance players delivered the off-break at a statistically significant higher velocity (75.1 and 67.1 km/hr respectively) and with a higher level of spin (26.7 and 22.2 rev/s respectively). Large effect sizes were seen between ball rotation, pelvic and shoulder alignment rotations in the transverse plane. Elbow extension was larger for elite bowlers over the period upper arm horizontal to ball release. Compared to the off-break, larger ranges of shoulder horizontal rotation, elbow and wrist extension were evident for the "doosra". Furthermore, the "doosra" was bowled with a significantly longer stride length and lower ball release height. Although not significantly different, moderate to high effect size differences were recorded for pelvis rotation, elbow extension and elbow rotation ranges of motion.
Publisher: Elsevier BV
Date: 07-2009
DOI: 10.1016/J.JBIOMECH.2009.03.039
Abstract: Identification of the centre of the glenohumeral joint (GHJ) is essential for three-dimensional (3D) upper limb motion analysis. A number of convenient, yet un-validated methods are routinely used to estimate the GHJ location in preference to the International Society of Biomechanics (ISB) recommended methods. The current study developed a new regression model, and simple 3D offset method for GHJ location estimation, employing easy to administer measures, and compared the estimates with the known GHJ location measured with magnetic resonance imaging (MRI). The accuracy and reliability of the new regression and simple 3D offset techniques were compared with six established predictive methods. Twenty subjects wore a 3D motion analysis marker set that was also visible in MRI. Immediately following imaging, they underwent 3D motion analysis acquisition. The GHJ and anatomical landmark positions of 15 participants were used to determine the new regression and simple 3D generic offset methods. These were compared for accuracy with six established methods using 10 subject's data. A cross validation on 5 participants not used for regression model development was also performed. Finally, 10 participants underwent a further two MRI's and subsequent 3D motion analysis analyses for inter-tester and intra-tester reliability quantification. When compared with any of the other established methods, our newly developed regression model found an average GHJ location closer to the actual MRI location, having an GHJ location error of 13+/-2 mm, and had significantly lower inter-tester reliability error, 6+/-4 mm (p<0.01).
Publisher: Science and Medicine, Inc.
Date: 06-2017
Abstract: BACKGROUND: Elite cello playing requires complex and refined motor control. Cellists are prone to right shoulder and thoracolumbar injuries. Research informing injury management of cellists and cello pedagogy is limited. The aims of this study were to quantify the torso, right shoulder, and elbow joint movement used by elite cellists while performing a fundamental playing task, a C major scale, under two volume conditions. METHODS: An eight degrees of freedom upper limb biomechanical model was applied to 3D motion capture data of the torso, upper arm, and forearm for 31 cellists with a mean experience of 19.4 yrs (SD 9.1). Two-factor ANOVA compared the joint positions between the four cello strings and two volume conditions. FINDINGS: Significant (p .05) effects were found for either the string and/or volume conditions across all torso, shoulder, and elbow joint degrees of freedom. The torso was consistently positioned in left rotation from 5.0° (SD 5.6) at the beginning of the scale, increasing to 16.3° (5.5) at its apogee. The greatest mean shoulder flexion, internal rotation, and abduction joint angles were observed when playing at the tip of the bow on the top string (A): 107.2° (11.6), 59.1° (7.1), and -76.9° (15.7), respectively, during loud playing. INTERPRETATION: Elite cellists use specific movement patterns to achieve string crossings and volume regulation during fundamental playing tasks. Implications of the static left-rotated torso posture and high degrees of combined shoulder flexion and internal rotation can be used to inform clinical and pedagogical practices.
Publisher: Elsevier BV
Date: 02-2016
DOI: 10.1016/J.JSAMS.2015.02.011
Abstract: This study aimed to identify modifiable mechanisms associated with low back injury in adolescent cricket fast bowlers. A prospective study design examined the association between intrinsic risk factors, workload, bowling kinematics, lumbar load and low back injury incidence. Twenty-five injury free fast bowlers, aged 14-19 years, were assessed prior to the start of a cricket season and observed during the season for low back injuries. The twelve bowlers who suffered a low back injury displayed decreased hip flexion at front foot contact (46±6° vs 51±6°), increased pelvis rotation (287±11° vs 277±11°) increased thorax lateral flexion (50±6° vs 40±8°) at ball release, and larger peak lumbar flexion (10.5±4.9Nmkg(-1)m(-1) vs 6.9±2.5Nmkg(-1)m(-1)) and lateral flexion moments (12.5±2.6Nmkg(-1)m(-1) vs 10.6±1.9Nmkg(-1)m(-1)). They also exhibited reduced muscular endurance of the back extensors (103±33s vs 132±33s) and increased knee valgus angle during a single leg decline squat on the dominant (9±3° vs 5±4°) and non-dominant leg (9±4° vs 6±3°) in comparison to uninjured bowlers. Bowlers who experience greater lumbar loads during bowling, have reduced back extensor muscle endurance, and demonstrate impaired control of the lumbo-pelvic-hip complex, are at increased risk of low back injury. This combination of strength, control and biomechanical factors may be key mechanical elements of low back injury causation in adolescent fast bowlers.
Publisher: MDPI AG
Date: 07-2021
DOI: 10.3390/S21134535
Abstract: The application of artificial intelligence techniques to wearable sensor data may facilitate accurate analysis outside of controlled laboratory settings—the holy grail for gait clinicians and sports scientists looking to bridge the lab to field ide. Using these techniques, parameters that are difficult to directly measure in-the-wild, may be predicted using surrogate lower resolution inputs. One ex le is the prediction of joint kinematics and kinetics based on inputs from inertial measurement unit (IMU) sensors. Despite increased research, there is a paucity of information examining the most suitable artificial neural network (ANN) for predicting gait kinematics and kinetics from IMUs. This paper compares the performance of three commonly employed ANNs used to predict gait kinematics and kinetics: multilayer perceptron (MLP) long short-term memory (LSTM) and convolutional neural networks (CNN). Overall high correlations between ground truth and predicted kinematic and kinetic data were found across all investigated ANNs. However, the optimal ANN should be based on the prediction task and the intended use-case application. For the prediction of joint angles, CNNs appear favourable, however these ANNs do not show an advantage over an MLP network for the prediction of joint moments. If real-time joint angle and joint moment prediction is desirable an LSTM network should be utilised.
Publisher: Elsevier BV
Date: 05-2012
DOI: 10.1016/J.JSAMS.2011.11.251
Abstract: To describe the prevalence and nature of lumbar spinal abnormalities in adolescent cricket fast bowlers. Observational study. 46 asymptomatic fast bowlers aged 13-18 years participated in the study and were grouped into under-15 (U15), under-17 (U17) and under-19 (U19) classifications. All participants underwent magnetic resonance imaging of the lumbar spine and abnormalities of the pars interarticularis and intervertebral discs were graded according to type and severity. Other abnormalities were also noted. Fifteen bowlers (33%) had at least one pars interarticularis abnormality. Six bilateral and 10 unilateral defects were identified. Of the 10 unilateral pars abnormalities, 6 occurred on the non-dominant side. Nineteen of the abnormalities occurred at the L5 vertebral level, 2 at L4 and 1 at L3. The most common type of pars abnormality was the subtotal stress fracture, which was found in 38% of bowlers aged 16 years and under. Sixteen participants (35%) were found to have degeneration of at least 1 lumbar disc and the prevalence increased with each successive age group (29% U15, 33% U17 and 43% U19). Of the 25 discs with signs of degeneration, 9 occurred at L4/5 and 7 at L5/S1. Eleven of these were classified as mild degeneration, 13 as moderate, and 1 as severe. Disc bulges were found in 33% of participants. Lumbar radiological abnormalities are common in asymptomatic adolescent fast bowlers. Acute bone stress reactions of the lumbar pars interarticularis are visible on magnetic resonance imaging and, in some instances, occur before the onset of activity-related pain.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.JBIOMECH.2016.11.057
Abstract: To appropriately use inverse kinematic (IK) modelling for the assessment of human motion, a musculoskeletal model must be prepared 1) to match participant segment lengths (scaling) and 2) to align the model׳s virtual markers positions with known, experimentally derived kinematic marker positions (marker registration). The purpose of this study was to investigate whether prescribing joint co-ordinates during the marker registration process (within the modelling framework OpenSim) will improve IK derived elbow kinematics during an overhead sporting task. To test this, the upper limb kinematics of eight cricket bowlers were recorded during two testing sessions, with a different tester each session. The bowling trials were IK modelled twice: once with an upper limb musculoskeletal model prepared with prescribed participant specific co-ordinates during marker registration - MR
Publisher: Informa UK Limited
Date: 22-05-2018
DOI: 10.1080/02640414.2017.1329547
Abstract: Spin bowling plays a fundamental role within the game of cricket yet little is known about the initial ball kinematics in elite and pathway spin bowlers or their relationship to performance. Therefore, the purpose of this study was to record three-dimensional ball kinematics in a large and truly high level cohort of elite and pathway finger-spin (FS) and wrist-spin (WS) bowlers, identifying potential performance measures that can be subsequently used in future research. A 22-camera Vicon motion analysis system captured retro-reflective markers placed on the seam (static) and ball (dynamic) to quantify ball kinematics in 36 FS (12 elite and 24 pathway) and 20 WS (eight elite and 12 pathway) bowlers. Results indicated that FS bowlers delivered the ball with an increased axis of rotation elevation, while wrist-spin bowlers placed greater amounts of revolutions on the ball. It also highlighted that ball release (BR) velocity, revolutions and velocity/revolution index scores for both groups and seam stability for FS bowlers, and seam azimuth angle and spin axis elevation angle for WS bowlers, were discriminators of playing level. As such these variables could be used as indicators of performance (i.e. performance measures) in future research.
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2020
Publisher: Springer Science and Business Media LLC
Date: 11-06-2019
Publisher: Elsevier BV
Date: 10-2021
Publisher: BMJ
Date: 11-2007
Publisher: Elsevier BV
Date: 02-2014
DOI: 10.1016/J.HUMOV.2013.07.021
Abstract: This study aimed to investigate the kicking limb coordinative patterns adopted by karate practitioners (karateka) when impacting (IRK), or not impacting (NIRK) a target during a roundhouse kick. Six karateka performed three repetitions of both kicks while kicking limb kinematics were recorded using a stereophotogrammetric system. Intra-limb coordination was quantified for hip and knee flexion-extension from toe-off to kick completion, using the Continuous relative phase (CRP). Across the same time interval, thigh and shank angular momentum about the vertical axis of the body was calculated. For all trials, across all participants, CRP curve peaks and maximum and minimum angular momentum were determined. A RM-ANOVA was performed to test for differences between kicking conditions. The CRP analysis highlighted, during the central portion of both kicks, a delayed flexion of the hip with respect to the knee. Conversely, during the terminal portion of the CRP curves, the NIRK is performed with a more in-phase action, caused by a higher hip angular displacement. The NIRK is characterized by a lower angular momentum which may enhance control of the striking limb. It would seem that the issue of no impact appears to be solved through the control of all segments of the kicking limb, in contrast to the primary control of the lower leg only observed during the IRK.
Publisher: Elsevier BV
Date: 2011
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 03-2019
Publisher: Springer Singapore
Date: 22-12-2017
Publisher: Elsevier BV
Date: 05-2018
Publisher: Elsevier BV
Date: 02-2021
Publisher: Elsevier BV
Date: 2021
Publisher: Elsevier BV
Date: 07-2008
Publisher: Elsevier BV
Date: 2014
DOI: 10.1016/J.JSAMS.2013.04.013
Abstract: The mechanical properties of the floors used by dancers have often been suggested to be associated with injury, yet limited etiological evidence is available to support this hypothesis. The dance floors at three theatres regularly used by a touring professional ballet company were mechanically quantified with the aim of comparing floor properties with injury incidence in dancers. Cross sectional. Test points on the floors were quantified in accordance with European Sports Surface Standard protocols for force reduction. Injuries and associated variables occurring within the ballet company dancers during activity on the three floors were recorded by the company's medical staff. An injury was recorded if a dancer experienced an incident that restricted the dancer from performing all normal training or performance activities for a 24 h period. Injuries were delimited to those occurring in the lower limbs or lumbar region during non-lifting tasks. Floor construction varied between venues and a range of floor mechanical properties were observed. None of the floors complied with the range of force reduction values required by the European Sport Surface Standards. The highest injury rate was observed on the floor with the greatest variability of force reduction magnitudes. No difference in injury frequency was observed between the venues with the highest and lowest mean force reduction magnitudes. Professional dancers can be required to perform on floors that may be inadequate for safe dance practice. Intra-floor force reduction variability may have a stronger association with injury risk than mean floor force reduction magnitude.
Publisher: Public Library of Science (PLoS)
Date: 07-04-2016
Publisher: Elsevier BV
Date: 02-2021
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2019
DOI: 10.1519/JSC.0000000000002889
Abstract: Nicholas, JC, McDonald, KA, Peeling, P, Jackson, B, Dimmock, JA, Alderson, JA, and Donnelly, CJ. Pole dancing for fitness: The physiological and metabolic demand of a 60-minute class. J Strength Cond Res 33(10): 2704–2710, 2019—Little is understood about the acute physiological or metabolic demand of pole dancing classes. As such, the aims of this study were to quantify the demands of a standardized recreational pole dancing class, classifying outcomes according to American College of Sports Medicine (ACSM) exercise-intensity guidelines, and to explore differences in physiological and metabolic measures between skill- and routine-based class components. Fourteen advanced-level amateur female pole dancers completed three 60-minute standardized pole dancing classes. In one class, participants were fitted with a portable metabolic analysis unit. Overall, classes were performed at a mean V o 2 of 16.0 ml·kg −1 ·min −1 , total energy cost (EC) of 281.6 kcal (4.7 kcal·min −1 ), metabolic equivalent (METs) of 4.6, heart rate of 131 b·min −1 , rate of perceived exertion (RPE) of 6.3/10, and blood lactate of 3.1 mM. When comparing skill- and routine-based components of the class, EC per minute (4.4 vs. 5.3 kcal·min −1 ), peak V o 2 (21.5 vs. 29.6 ml·kg −1 ·min −1 ), METs (4.3 vs. 5.2), and RPE (7.2 vs. 8.4) were all greater in the routine-based component ( p 0.01), indicating that classes with an increased focus on routine-based training, as compared to skill-based training, may benefit those seeking to exercise at a higher intensity level, resulting in greater caloric expenditure. In accordance with ASCM guidelines, an advanced-level 60-minute pole dancing class can be classified as a moderate-intensity cardiorespiratory exercise when completed for ≥30 minutes, ≥5 days per week (total ≥150 minutes) satisfies the recommended level of exercise for improved health and cardiorespiratory fitness.
Publisher: SAGE Publications
Date: 30-07-2018
Abstract: Cricket bowlers must be able to deliver the ball with less than 15° of elbow extension or face suspension. The aim of this case study was to report the findings of a technique remediation programme on the elbow joint kinematics of an international cricket bowler. The bowler underwent a three-dimensional bowling analysis to measure his elbow joint kinematics before and after a technique remediation programme. The bowler was required to bowl six deliveries of each of his off-break, quicker and doosra variations. The remediation programme focussed on modifying the bowler’s run-up, shoulder alignment and ball/hand position at back foot impact. Elbow joint waveform data were analysed using statistical parametric mapping tests and coefficient of multiple determination. Elbow flexion–extension angles at discrete events were compared pre- and post-remediation using paired-s le t-tests. Results showed that the remediation programme was effective in reducing the amount of elbow flexion, particularly in the first 60% of the delivery cycle. Elbow extension range was significantly lower post-remediation for the off-break and quicker deliveries. It was concluded that basic short-term technique remediation can be effective in reducing elbow extension range.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2013
Publisher: Informa UK Limited
Date: 11-2006
DOI: 10.1080/02640410500497618
Abstract: The aim of this study was to examine the relationship between shoulder alignment and elbow angle during the delivery action of fast-medium bowlers. The elbow and upper trunk alignment were recorded for 13 high-performance bowlers (mean age 20 years) using a 12-camera Vicon motion analysis system operating at 250 Hz. The three highest velocity trials for "good" and "short" length deliveries were analysed. Results showed that bowlers with a more front-on shoulder alignment at back-foot impact and when the upper arm was horizontal to the ground experienced a significantly greater elbow flexion--extension range when compared with those who had a more side-on orientation at the same point in the delivery action. Bowlers with greater shoulder counter-rotation also recorded higher elbow flexion and subsequently extension during the period from upper arm horizontal to ball release. Shoulder alignment and elbow angles were similar for "short" and "good" length deliveries. It was concluded that bowlers with a more front-on shoulder orientation at back-foot impact demonstrated a higher elbow extension from upper arm horizontal to ball release and are therefore more likely to infringe International Cricket Council elbow tolerance levels, compared with those who adopt a more side-on shoulder orientation at back-foot impact.
Publisher: Elsevier BV
Date: 05-2010
DOI: 10.1016/J.GAITPOST.2010.02.015
Abstract: There is increasing demand for a standardised and reliable protocol for the objective assessment of upper limb motion in clinical populations. This paper describes the repeatability of a three-dimensional (3D) kinematic model and protocol to assess upper limb movement for children with and without cerebral palsy (CP). Ten typically developing (TD) children (m=10.5years+/-1.18) and seven children with CP (spastic hemiplegia) (m=11.14years+/-1.86) completed upper limb motion analysis on two occasions separated by at least one week. Participants performed three trials of four functional tasks, where 3D joint angles were calculated at the thorax, shoulder, elbow and wrist. Within and between-day repeatability was assessed using coefficients of multiple determination (CMD). There were distinct kinematic patterns for both groups for each functional task. In relation to their peers, children with CP consistently displayed reduced elbow extension, and compensatory patterns at the shoulder and thorax. High within and between-day CMD scores were revealed for specific rotations, with the highest being obtained at joints with large ranges of motion. The chosen tasks delineate the upper limb kinematic patterns of those with and without CP. The model has high within and between-day repeatability particularly where joint rotations demonstrate a large range of movement. 3D motion analysis is a feasible assessment tool for use with clinical populations.
Publisher: Wiley
Date: 04-03-2010
DOI: 10.1111/J.1469-8749.2009.03409.X
Abstract: To determine the neuromuscular outcomes of an eccentric strength-training programme for children and adolescents with cerebral palsy (CP). In this randomised, parallel-group trial with waiting control, 14 participants with CP (six males, eight females mean age 11y, SD 2y range 9-15y), diagnosed with upper-limb spasticity were compared with 14 age- and sex-matched typically developing participants. Participants with CP completed a 6-week progressive resistance-strengthening programme, performing eccentric lengthening contractions of their upper limb three times a week. Data from dynamometer and surface electromyography (EMG) assessments included peak torque normalised to body mass (T/Bm), work normalised to body mass (W/Bm), angle at peak torque, curve width, and EMG activation. After training, children with CP had improved eccentric T/Bm (p=0.009) and W/Bm (p=0.009) to a level similar to that of the typically developing children. No change in angle of peak torque occurred, although curve width increased both concentrically (p=0.018) and eccentrically (p=0.015). EMG activity was elevated before training in children with CP but decreased with training to levels similar to those of the typically developing children. With eccentric strength training, children with CP increased torque throughout range of motion. Results suggest that eccentric exercises may decrease co-contraction, improving net torque development. Eccentric actions may be important in the maintenance of the torque-angle relationship. These results have significant implications for the prescription of strength-training programmes for people with CP.
Publisher: SAGE Publications
Date: 06-2011
Abstract: Dance floor surfaces are important environmental factors in dance activity and have been suggested to be a factor in the aetiology of dance injury. Measurement of the injury risk associated with floor surfaces is difficult as the validity of the relationship between mechanical surface measures and human–surface interactions is unclear. Dancer perceptions of the mechanical properties of floor surfaces were investigated with reference to mechanical quantification measures. Student ( n = 27) and professional ( n = 27) dancers completed a questionnaire investigating their perceptions of the force reduction, vertical deformation, energy restitution and overall ratings of five s le dance floors. Dance floor mechanical properties were quantified using sport surface testing apparatus, the Advanced Artificial Athlete (AAA) (Metaalmaatwerk, Netherlands). Student and professional cohort perceptions were not significantly different for 18 of the 20 perception variables. Vertical deformation was the only mechanical variable to differ between cohort perceptions. Dancers demonstrated a preference for floors with greater force reduction magnitudes than specified by European sport surface standards, suggesting that bespoke floor standards for dance may be beneficial. Considerable discrepancies were found between particular dancer perceptions and related AAA outputs, highlighting the need for further investigation of valid mechanical tests that are used to represent human–surface interactions.
Publisher: BMJ
Date: 18-05-2007
Publisher: Informa UK Limited
Date: 19-11-2019
DOI: 10.1080/02640414.2018.1545276
Abstract: Increasing knee stability via appropriate muscle activation could reduce anterior cruciate ligament (ACL) injury risk during unplanned sidestepping. High-level athletes may activate their knee muscles differently from low-level athletes when responding to quasi-game realistic versus non game-realistic stimuli. Eleven high-level and 10 low-level soccer players responded to a non game-realistic arrow-planned condition (AP), a quasi game-realistic one-defender scenario (1DS) and two-defender scenario (2DS), and an arrow-unplanned condition (AUNP), that imposed increasing time constraints to sidestep. Activation from eight knee muscles during sidestepping was measured during pre-contact and weight-acceptance. Knee flexor-extensor co-activation ratios were established. Muscle activation levels increased by approximately 27% solely in the 1DS in both sidestepping phases. In the 2DS, the shift from a flexor dominant co-activation strategy in pre-contact toward extensor dominance in weight-acceptance commenced earlier for the high-level players. Quasi game-realistic information allowed for anticipatory increases in knee muscle activation regardless of expertise levels but only when the time demands to respond were low (1DS). High-level players were better at interpreting complex game-realistic information (2DS) to activate their knee extensors earlier in preparation for single-leg landing during weight-acceptance.
Publisher: Wiley
Date: 27-02-2018
DOI: 10.1111/SMS.13070
Abstract: With advances in technology, scientists are now able to more accurately measure elbow displacement changes during the cricket bowling action. This has led to the realization that the majority of bowlers undergo some degree of elbow extension during the forward swing phase of bowling. Consequently, the International Cricket Council were obliged to revise the once zero tolerance for elbow extension threshold to a 15° range. However, it is still not understood if bowling with >15° of elbow extension aids performance or alters other kinematic movements. The purpose of this study was to compare performance and technique measures between legal and illegal finger-spin bowlers. Data were collected from 48 pathway and elite bowlers using a 22-camera motion analysis system. Results indicated that the ball velocity and revolutions at ball release of pathway bowlers with illegal actions showed no significant difference and were similar to elite legal bowlers. Technique differences were also identified, with illegal bowlers being more front-on, forcing a reliance on increased elbow flexion and supination to impart effective ball kinematics at ball release. The performance benefit of greater ball velocity and revolutions is obtained when finger-spin bowlers deliver the ball with more than the allowable 15° of elbow extension, thus reinforcing the validity of the current bowling laws. To counteract bowling with an illegal action, it is recommended that a more side-on technique at back foot impact and rotating the trunk through to the point of ball release will assist bowlers in reducing undesirable elbow extension levels.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2013
Publisher: Elsevier BV
Date: 2007
DOI: 10.1016/J.JBIOMECH.2006.12.012
Abstract: The system and modelling errors of two fundamentally different motion capture systems (opto-reflective vs. video-based) were tested under various conditions, to determine their ability to accurately measure flexion-extension of the elbow angle in cricket bowling. A mechanical arm was used for all testing, that enabled known elbow flexion-extension and abduction ("carry") angles to be manually set. The root mean squared (RMS) error of 0.6 degrees for the opto-reflective system (Vicon-612) was more accurate in reconstructing a known angle than the video-based system (Peak Motus) (RMS error 2.3 degrees ) in the laboratory, when the same mathematical procedure (model) was applied to calculate the elbow flexion-extension angle. When different models were applied to the raw marker trajectories collected using the video-based system, RMS was lowest for the external marker segmental cluster models (2.3 degrees ) compared with 9.4 degrees for the vector and 4.5 degrees for the projected vector approaches, where joint centres were visually approximated. Real world, field-based comparisons using the video-based system showed that occluding the arm and therefore the shoulder, elbow and wrist joint centre locations by placing a shirt on the arm, increased RMS error for both vector (7.8 degrees -9.0 degrees ) and projected vector (4.3 degrees -5.1 degrees ) modelling approaches.
Publisher: Informa UK Limited
Date: 24-02-2017
DOI: 10.1080/14763141.2016.1246597
Abstract: This study aims to determine if biomechanically informed injury prevention training can reduce associated factors of anterior cruciate ligament injury risk among a general female athletic population. Female community-level team sport athletes, split into intervention (n = 8) and comparison groups (n = 10), completed a sidestepping movement assessment prior to and following a 9-week training period, in which kinetic, kinematic and neuromuscular data were collected. The intervention group completed a biomechanically informed training protocol, consisting of plyometric, resistance and balance exercises, adjunct to normal training, for 15-20 min twice a week. Following the 9-week intervention, total activation of the muscles crossing the knee (n = 7) decreased for both the training (∆ -15.02%, d = 0.45) and comparison (∆ -9.68%, d = 0.47) groups. This decrease was accompanied by elevated peak knee valgus (∆ +27.78%, d = -0.36) and internal rotation moments (∆ +37.50%, d = -0.56) in the comparison group, suggesting that female community athletes are at an increased risk of injury after a season of play. Peak knee valgus and internal rotation knee moments among athletes who participated in training intervention did not change over the intervention period. Results suggest participation in a biomechanically informed training intervention may mitigate the apparent deleterious effects of community-level sport participation.
Publisher: Springer Science and Business Media LLC
Date: 19-01-2016
DOI: 10.1038/SREP19403
Abstract: The energy-sparing spring theory of the foot’s arch has become central to interpretations of the foot’s mechanical function and evolution. Using a novel insole technique that restricted compression of the foot’s longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms −1 ) level running increased metabolic cost by + 6.0% ( p 0.001, d = 0.67 unaffected by foot strike technique). A simple model shows that the metabolic energy saved by the arch is largely explained by the passive-elastic work it supplies that would otherwise be done by active muscle. Both experimental and model data confirm that it is the end-range of arch compression that dictates the energy-saving role of the arch. Restricting arch compression had no effect on the cost of walking or incline running (3°), commensurate with the smaller role of passive-elastic mechanics in these gaits. These findings substantiate the elastic energy-saving role of the longitudinal arch during running and suggest that arch supports used in some footwear and orthotics may increase the cost of running.
Publisher: Elsevier BV
Date: 08-2019
DOI: 10.1016/J.JBIOMECH.2019.07.002
Abstract: In sports analytics, an understanding of accurate on-field 3D knee joint moments (KJM) could provide an early warning system for athlete workload exposure and knee injury risk. Traditionally, this analysis has relied on captive laboratory force plates and associated downstream biomechanical modeling, and many researchers have approached the problem of portability by extrapolating models built on linear statistics. An alternative approach would be to capitalize on recent advances in deep learning. In this study, using the pre-trained CaffeNet convolutional neural network (CNN) model, multivariate regression of marker-based motion capture to 3D KJM for three sports-related movement types were compared. The strongest overall mean correlation to source modeling of 0.8895 was achieved over the initial 33% of stance phase for sidestepping. The accuracy of these mean predictions of the three critical KJM associated with anterior cruciate ligament (ACL) injury demonstrate the feasibility of on-field knee injury assessment using deep learning in lieu of laboratory embedded force plates. This multidisciplinary research approach significantly advances machine representation of real-world physical models with practical application for both community and professional level athletes.
Publisher: Informa UK Limited
Date: 07-2005
DOI: 10.1080/02640410400022177
Abstract: The aim of this study was to assess the effect of pitch length (20.12 m [full length], 18 m and 16 m) on the fast bowling performance and technique of junior cricketers. Performance measures included ball release speed and accuracy, while technique variables evaluated were those shown to be related to the aetiology of lower back injury. Thirty-seven fast bowlers from the under-11 (n=14), under-13 (n=11) and under-15 (n=12) age groups were filmed bowling five deliveries at each of the above pitch lengths. Two synchronized NAC video cameras operating at 200 Hz permitted three-dimensional reconstruction of the hip and shoulder alignments, while a standard digital video camera operating at 50 Hz (positioned perpendicular to the bowling action) was used to measure front knee angle and ball release speed. Accuracy scores were taken from a zoned target at the batsman's stumps. A two-way analysis of variance with repeated measures (with age and pitch length as the between- and within-participant variables, respectively) was used to compare each age group at the 0.05 significance level. Results showed that accuracy improved in all age groups at shorter pitch lengths, although ball velocity remained constant throughout all trials. Shoulder counter-rotation increased significantly for the under-13 bowlers when bowling on the full-length pitch in comparison with the two shorter lengths. Counter-rotation also increased on the full-length pitch in the under-11 age group, although this increase was not significant. The under-15 bowlers' techniques did not change as pitch length increased. As under-11 and under-13 bowlers adopted a "safer" bowling action with superior accuracy on the 18?m compared with the full length pitch, it was concluded that these age groups should bowl on an 18?m pitch to reduce the likelihood of lower back injuries and improve accuracy.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2008
DOI: 10.1249/MSS.0B013E31815C6D61
Abstract: To examine the relationship between variable lower-limb coordination and shoulder joint kinetics and kinematics in the high-performance flat first serve in tennis. Three-dimensional data describing three flat serve (FS) techniques, each executed with varying lower-limb involvement: foot-up (FU), foot-back (FB), and minimal leg drive (ARM), as performed by 12 high-performance male players were recorded using a 12-camera Vicon MX motion analysis system operating at 250 Hz. A discriminant analysis determined the lower-limb kinematics that distinguished serve technique, and by extension, leg drive. A total of 18 one-way ANOVA ascertained statistically significant differences in the kinematic and kinetic variables considered to relate to or represent shoulder joint loading in FU, FB, and ARM serves. The lower-limb kinematics shown to best discriminate between service techniques were range of rear and front knee joint extension, and peak angular velocity of rear knee joint extension. The forward swings of the FU (43.6 +/- 3.0 m.s(-1), P < 0.05) and FB (42.6 +/- 3.1 m.s(-1), P < 0.05) techniques were characterized by higher peak racket speeds than those generated in the ARM (39.4 +/- 3.4 m.s(-1)) serve. Regardless of stance and leg drive, similar pre- and post-impact shoulder joint kinetics were developed. Knowledge of a server's range of front and rear knee joint extension as well as his/her peak angular velocity of rear knee joint extension is sufficient to ascertain the stance and quality of leg drive used. When facilitated by a leg drive, high-performance players generate similar resultant pre-impact racket velocities independent of stance. With no leg drive, players develop lower resultant racket velocities. Comparable shoulder joint kinetics, however, evolved from the differential lower-limb mechanics that characterized the FU, FB, and ARM techniques.
Publisher: Springer Science and Business Media LLC
Date: 10-04-2012
Publisher: Georg Thieme Verlag KG
Date: 10-01-2019
DOI: 10.1055/A-0756-9659
Abstract: This study aimed to develop a 2-dimensional (2D) video screening tool capable of predicting an athlete’s peak 3-dimensional (3D) knee moments during unplanned sidestepping. 2D video-based kinematic measures were simultaneously captured with 3D peak knee moments for 30 female field hockey players (15 junior, 15 senior). Intra- and intertester repeatability of 2D kinematic measures was performed. Then, linear regression models were used to model 3D knee moments from 2D kinematic variables utilizing 80% of the s le (n=24). Regression equations were then validated on the remaining 20% of the s le (n=6). Angular 2D measures had good-excellent intra- (ICC=0.936–0.998) and intertester (ICC=0.662–0.949) reliability. Displacement measures had poor-excellent intra- (ICC=0.377–0.539) and inter-tester (ICC=0.219–0.869) reliability. Significant independent predictors of peak knee moments were dynamic knee valgus, knee flexion angle at foot strike, trunk flexion range of motion (ROM), trunk lateral flexion, hip abduction and knee flexion ROM (P .05). Regression equations generated from these models effectively predicted peak knee extension, valgus and internal rotation moments (i. e., were not different from measured values P .05, ES .4) in the 20% subs le. 2D video-based measurements of an athlete's full body kinematics during unplanned sidestepping provide a reliable, specific, sensitive and cost-effective means for screening female team sport athletes.
Publisher: MDPI AG
Date: 29-08-2022
DOI: 10.3390/S22176522
Abstract: To increase the utility of legacy, gold-standard, three-dimensional (3D) motion capture datasets for computer vision-based machine learning applications, this study proposed and validated a method to synthesise two-dimensional (2D) video image frames from historic 3D motion data. We applied the video-based human pose estimation model OpenPose to real (in situ) and synthesised 2D videos and compared anatomical landmark keypoint outputs, with trivial observed differences (2.11–3.49 mm). We further demonstrated the utility of the method in a downstream machine learning use-case in which we trained and then tested the validity of an artificial neural network (ANN) to estimate ground reaction forces (GRFs) using synthesised and real 2D videos. Training an ANN to estimate GRFs using eight OpenPose keypoints derived from synthesised 2D videos resulted in accurate waveform GRF estimations (r 0.9 nRMSE 14%). When compared with using the smaller number of real videos only, accuracy was improved by adding the synthetic views and enlarging the dataset. The results highlight the utility of the developed approach to enlarge small 2D video datasets, or to create 2D video images to accompany 3D motion capture datasets to make them accessible for machine learning applications.
Publisher: Elsevier BV
Date: 12-2014
Publisher: Springer Science and Business Media LLC
Date: 16-07-2020
Publisher: SAGE Publications
Date: 15-03-2016
Abstract: An international cricket spin bowler was experiencing asymmetrical low back pain while bowling his off-break delivery. The aim of this study was to identify technical discrepancies between the bowler’s off-break delivery and his other variations, which did not cause low back pain. The bowler underwent a three-dimensional kinematic bowling analysis based on data captured using a 14-camera Vicon system operating at 250 images per second. To increase task representativeness, the analysis was undertaken outdoors on a turf cricket pitch. The bowler was required to bowl six deliveries of his off-break delivery and three variations. A range of pelvic and trunk kinematics were measured. A one-way independent s les analysis of variance with planned comparisons and a bootstrapping procedure was used to identify technical differences between the delivery types. Results showed that the off-break delivery displayed significantly higher trunk alignment, shoulder counter-rotation, trunk contralateral flexion and ‘crunch factor’ when compared with other delivery variations. It was concluded that the bowler who participated in this study was using an off-break technique that exhibited technical characteristics that have previously been associated with an increased likelihood of sustaining a lower back injury.
Publisher: Springer International Publishing
Date: 2022
Publisher: Informa UK Limited
Date: 03-09-2019
DOI: 10.1080/02640414.2018.1512845
Abstract: Magnetic and inertial measurement units (MIMUs) may provide an accessible, three-dimensional, in-field alternative to laboratory-restricted marker-based motion capture. Existing upper limb MIMU models have predominantly been validated with low-velocity motion and their suitability for use with sport-based movements remains relatively untested. We propose a MIMU system approach to enable the estimation of anatomically meaningful and participant-specific elbow kinematics with considerations for use with cricket bowling. A novel standardised elbow reference posture of 90 degrees flexion and 0 deg pronation, and functional definition of elbow joint axes of rotation calibrated the MIMU method model before it was validated across three experiments: (1) simple elbow rotations with a mechanical linkage (2) low-velocity elbow rotations in human participants and (3) low-medium velocity sport-based movements in human participants. The proposed MIMU method demonstrated high elbow kinematic measurement agreement when compared with a criterion measure across all three conditions. However, during experiment 3, sensor components neared their measurement capacity and the MIMU method elbow flexion measurement variability increased. We conclude that the proposed MIMU method can estimate anatomically referenced, participant-specific joint angles, however, the hardware specifications of currently available systems may limit application in high-velocity/acceleration situations, preventing the measurement of cricket bowling in-field for now.
Publisher: Informa UK Limited
Date: 25-11-2019
DOI: 10.1080/02640414.2019.1696265
Abstract: Delivering a cricket ball with a wrist-spin (WS) bowling technique is considered one of the game's most difficult skills. Limited biomechanical information exists for WS bowlers across skill levels. The purpose of this study was to compare biomechanical, isokinetic strength and anthropometric measures between elite (12) and pathway bowlers (eight). Data were collected using a motion analysis system, dynamometer and a level-two anthropometrist. A regression analysis identified that performance was best explained by increased wrist radial deviation torque and longitudinal axis rotational moments at the shoulder and wrist. From back foot impact (BFI) to ball release (BR), elite bowlers rotated their trunks less, experienced less trunk deceleration resulting in a more front-on position and increased pelvis rotation angular velocity. They also displayed an increased shoulder internal rotation moment as the upper arm moved from external into internal rotation and was a major contributor in the subsequent differences observed in the distal segments of the bowling limb. Anthropometric differences were observed at the wrist and finger joints and may be used to form the basis for talent identification programmes. This study highlights the important contribution to bowling performance of the musculature responsible for producing long axis rotations of the bowling limb.
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.GAITPOST.2010.11.008
Abstract: To determine changes in upper limb movement substructures that denote fluency of movement in children with cerebral palsy (CP) following lycra(®) splint wear. Secondarily, to explore the efficacy of lycra(®) splints for those with spastic and dystonic hypertonia. Randomised clinical trial whereby participants were randomised to parallel groups with waiting list control. Sixteen children (mean age 11.5 years SD=2.2) with hypertonic upper limb involvement (13 hemiplegia, 4 quadriplegia) were recruited. Children were randomly allocated either to a control group or to wear the lycra(®) splint for a period of three months. Three-dimensional (3D) upper limb kinematics was used to assess four functional tasks at baseline, on initial lycra(®) splint application, three months after lycra(®) splint wear, and immediately after splint removal. Movement substructures of the motion of the wrist joint center were analysed. A significant difference was observed between baseline and three months of lycra(®) splint wear in the movement substructures movement time, percentage of time and distance in primary movement, jerk index, normalised jerk and percentage of jerk in primary and secondary movements. The magnitude of changes in normalised jerk and the percentage of jerk in the primary movement from baseline to three months was greatest in children with dystonic hypertonia. The results indicate that lycra(®) arm splinting induced significant changes in movement substructures and motor performance in children with CP. This research demonstrates that fluency of movement can be quantified and is amenable to change with intervention.
Publisher: No publisher found
Date: 2022
DOI: 10.1111/SMS.14194
Abstract: Frontal plane postures during the ultimate step of sidestepping are linked to increased anterior cruciate ligament injury risk. However, there is a lack of research detailing the kinematic strategies present in the penultimate step. This study, therefore, investigated penultimate and ultimate step kinematics of planned sidestepping (pSS) and unplanned sidestepping (upSS) to further understand the effect of planning time on known ultimate step kinematic and kinetic differences. Sixty male amateur Australian Rules football players performed three trials of straight-line running (RUN), pSS, and upSS in a randomized order. Mediolateral foot placement and three-dimensional joint kinematics for the knee, pelvis, and trunk were measured at final foot contact of the penultimate step and initial foot contact of the ultimate step. Peak knee moments were measured during the weight acceptance phase of the ultimate step. In pSS, at the penultimate step final foot contact, the support foot was placed across the midline of the center of mass, in the frontal plane, contralateral to the sidestep direction. Greater trunk lateral flexion toward the sidestep direction and greater negative pelvic lateral tilt were observed in pSS compared with upSS and RUN. Differences between pSS and upSS frontal plane kinematics at penultimate step final foot contact suggest preparatory reorientation strategies are likely constrained by the amount of planning time available. As there are clear differences in preparatory kinematics, we recommend that planning time be considered when training and assessing sidestepping maneuvers and planned and unplanned maneuvers not be treated as interchangeable skills.
Publisher: Informa UK Limited
Date: 06-2013
DOI: 10.1080/02640414.2012.762601
Abstract: This study aimed to assess changes in bowling technique and lumbar load over the course of a bowling spell in adolescent fast bowlers, and to investigate the relationship between lumbar loads during fast bowling and kinematic factors which have previously been associated with low back injury. Three-dimensional motion analysis was carried out on forty participants who performed an 8-over bowling spell. There were no significant changes in bowling technique or lumbar loads over the course of the spell. Bowling with a more extended front knee, faster ball release speed and increased shoulder counter-rotation were related to increased lumbo-pelvic loading - in particular peak transverse plane rotation moments and anterior-posterior shear forces. These lumbar loads may be a factor in low back injury aetiology and future studies should investigate the relationship between lumbar loading, injury incidence and other risk factors.
Publisher: Elsevier BV
Date: 11-2018
Publisher: Springer Science and Business Media LLC
Date: 03-04-2018
DOI: 10.1007/S11517-018-1820-5
Abstract: This study investigates the inter-tester repeatability of an upper limb direct kinematic (ULDK) model specifically for the reporting of elbow flexion-extension (FE) during overhead sporting movements, such as cricket bowling. The ULDK model consists of an upper arm and a forearm connected with a 6° of freedom elbow joint. The ULDK model was assessed for inter-tester repeatability by calculating elbow FE during cricket bowling in two sessions, with unique testers applying the kinematic marker set in each session. Analysis of both elbow FE time-varying waveforms (statistical parametric mapping = 0% time different) and extracted discrete events (no statistical differences, strong correlations > 0.9) support that this model is inter-tester repeatable at assessing elbow FE within the context of cricket bowling. This model is recommended as a framework in future studies for measuring elbow kinematics during other overhead sporting tasks, with recommendations for further participant-specific considerations. Graphical abstract ᅟ.
Publisher: Science and Medicine, Inc.
Date: 09-2022
Abstract: OBJECTIVE: Pole dancing is a challenging physical activity. Prospective injury studies in pole dancing are lacking. The aim of this study was to describe the incidence, mechanisms, and characteristics of injuries in pole dancers. METHODS: A total of 66 pole dancers from 41 studios across Australia were prospectively followed over 12 months. An intake questionnaire was administered including items on pole dancers’ demographics and training characteristics. Exposure was assessed using a daily online training diary. Self-reported injury data were collected via an incident report form and subsequently coded using the Orchard Sports Injury Classification System. Injuries occurring during pole-specific and pole-related activities were included in the analyses. RESULTS: The s le included 63 females and 3 males, mean age 32.3 ± 8.9 years and mean pole training experience 3.5 ± 2.8 years. 25 of 66 participants completed the full study. The 1-year incidence of all new injuries was 8.95/1,000 exposure hours (95% CI 6.94 – 10.96), 7.65/1,000 hrs (95% CI 5.79 – 9.51) for pole-specific injuries and 1.29/1,000 hrs (95% CI 0.53 – 2.06) for pole-related injuries. A total of 103 injuries occurred, 62.1% of which were sudden onset and 37.9% gradual onset. Mechanism of onset included 54.4% acute and 45.6% repetitive in nature. Shoulder (20.4%) and thigh (11.7%, majority ham¬string) were the most reported anatomic injury sites. Non-contact mechanisms accounted for the majority of injuries (57.3%). The most reported primary contributor to injury onset at the shoulder were manoeuvres characterised by loaded internal humeral rotation (33.3%), and at the hamstring were manoeuvres and postures involving front splits (100.0%). CONCLUSION: The findings indicate that pole dancers are at high risk for injuries. Future research is needed to understand the biomechani¬cal demand of manoeuvres and training characteristics of pole dancing (e.g., workload and recovery) to guide the development of preventative interventions, particularly targeted toward the shoulder and hamstring.
Publisher: Springer Science and Business Media LLC
Date: 12-2001
DOI: 10.1007/BF03178367
Publisher: Springer Singapore
Date: 10-10-2017
Publisher: Informa UK Limited
Date: 22-04-2021
Publisher: Springer Science and Business Media LLC
Date: 16-09-2021
DOI: 10.1007/S11517-021-02440-9
Abstract: Magneto-inertial measurement unit (MIMU) systems allow calculation of simple sensor-to-sensor Euler angles, though this process does not address sensor-to-segment alignment, which is important for deriving meaningful MIMU-based kinematics. Functional sensor-to-segment calibrations have improved concurrent validity for elbow and knee angle measurements but have not yet been comprehensively investigated for trunk or sport-specific movements. This study aimed to determine the influence of MIMU functional calibration on thorax and lumbar joint angles during uni-planar and multi-planar, sport-specific tasks. It was hypothesised that functionally calibrating segment axes prior to angle decomposition would produce smaller differences than a non-functional method when both approaches were compared with concurrently collected 3D retro-reflective derived angles. Movements of 10 fast-medium cricket bowlers were simultaneously recorded by MIMUs and retro-reflective motion capture. Joint angles derived from four different segment definitions were compared, with three incorporating functionally defined axes. Statistical parametric mapping and root mean squared differences (RMSD) quantified measurement differences one-dimensionally and zero-dimensionally, respectively. Statistical parametric mapping found no significant differences between MIMU and retro-reflective data for any method across bowling and uni-planar trunk movements. The RMSDs for the functionally calibrated methods and non-functional method were not significantly different. Functional segment calibration may be unnecessary for MIMU-based measurement of thorax and lumbar joint angles.
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.JELEKIN.2016.10.001
Abstract: There is a large and growing body of surface electromyography (sEMG) research using laboratory-specific signal processing procedures (i.e., digital filter type and litude normalisation protocols) and data analyses methods (i.e., co-contraction algorithms) to acquire practically meaningful information from these data. As a result, the ability to compare sEMG results between studies is, and continues to be challenging. The aim of this study was to determine if digital filter type, litude normalisation method, and co-contraction algorithm could influence the practical or clinical interpretation of processed sEMG data. Sixteen elite female athletes were recruited. During data collection, sEMG data was recorded from nine lower limb muscles while completing a series of calibration and clinical movement assessment trials (running and sidestepping). Three analyses were conducted: (1) signal processing with two different digital filter types (Butterworth or critically d ed), (2) three litude normalisation methods, and (3) three co-contraction ratio algorithms. Results showed the choice of digital filter did not influence the clinical interpretation of sEMG however, choice of litude normalisation method and co-contraction algorithm did influence the clinical interpretation of the running and sidestepping task. Care is recommended when choosing litude normalisation method and co-contraction algorithms if researchers/clinicians are interested in comparing sEMG data between studies.
Publisher: MDPI AG
Date: 06-02-2018
DOI: 10.3390/NU10020176
Publisher: IEEE
Date: 2013
Publisher: Informa UK Limited
Date: 03-2013
DOI: 10.1080/00222895.2012.760512
Abstract: The authors aimed to identify differences in (a) visual search and (b) reaction time when athletes sidestepped to intercept 2D versus 3D videoed opponents. They hypothesized that participants would (a) fixate on different parts of the opponent's body and (b) react quicker when responding to the 3D versus 2D opponent due to the added depth cues. A customized integrated stereoscopic system projected the video stimuli and synchronously recorded the gaze and motor behaviors of 10 men when they responded to two- (2D) and three-dimensional (3D) opponents. The number and duration of gaze fixations were coded according to locations on the opponent's body (head, shoulders, arms, trunk, pelvis, legs) or otherwise (other). Mediolateral pelvic movement was used to infer reaction time. Participants spent 16% less time fixating on the trunk and 23% more time outside the 3D opponent's body compared with the 2D stimulus. No reaction time differences were found. Although participants fixated less on the 3D opponent's body and, by inference, invested less perceptual processing toward interpreting the opponent's movements compared with the 2D condition, they performed the interception task equally fast in both conditions. Three-dimensional depth cues may provide more meaningful information per fixation for successful task performance.
Publisher: Informa UK Limited
Date: 02-02-2015
DOI: 10.1080/02640414.2014.1003586
Abstract: This modelling study sought to describe the relationships between elbow joint kinematics and wrist joint linear velocity in cricket fast bowlers, and to assess the sensitivity of wrist velocity to systematic manipulations of empirical joint kinematic profiles. A 12-camera Vicon motion analysis system operating at 250 Hz recorded the bowling actions of 12 high performance fast bowlers. Empirical elbow joint kinematic data were entered into a cricket bowling specific "Forward Kinematic Model" and then subsequently underwent fixed angle, angular offset and angle lification manipulations. A combination of 20° flexion and 20° abduction at the elbow was shown to maximise wrist velocity within the experimental limits. An increased elbow flexion offset manipulation elicited an increase in wrist velocity. Amplification of elbow joint flexion-extension angular displacement indicated that, contrary to previous research, elbow extension range of motion and angular velocity at the time of ball release were negatively related to wrist velocity. Some relationships between manipulated joint angular waveforms and wrist velocity were non-linear, supporting the use of a model that accounts for the non-linear relationships between execution and outcome variables in assessing the relationships between elbow joint kinematics and wrist joint velocity in cricket fast bowlers.
Publisher: Elsevier BV
Date: 04-2019
DOI: 10.1016/J.JSAMS.2018.10.006
Abstract: Appropriate statistical analysis of clustered data necessitates accounting for within-participant effects to ensure results are repeatable and translatable to real-world applications. This study aimed to compare statistical output and injury risk interpretation differences from two statistical regression models built from a clinical movement sidestepping database. A "naïve" regression model, which does not account for within-participant effects, was compared with an appropriately applied mixed effects model. Comparative study. Three-dimensional unplanned sidestepping joint angle data (trunk, hip, and knee) from 35 males (112 observations) were used to model peak knee valgus moments and anterior cruciate ligament injury risk during the impact phase of stance. Both statistical models were cross-validated using a k-fold analysis. The naïve regression returned inflated goodness of fit statistics (R A regression model naïvely applied to clustered observations of sidestepping data resulted in erroneous parameter estimates and goodness of fit statistics which have the potential to mislead future research and real-world applications. It is important for sport and clinical scientists to use statistically appropriate mixed effects models when modelling clustered motion capture data for injury biomechanics research to protect the translatability of the findings.
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.JSAMS.2016.06.002
Abstract: Compare the lower-limb mechanics and anterior cruciate ligament (ACL) injury risk of athletes using a habitual rear-foot (RF) and fore-foot (FF) fall pattern during unplanned sidestepping (UnSS). Experimental cross-sectional. Nineteen elite female field hockey players attended one biomechanical motion capture testing session, which consisted of a random series of pre-planned and unplanned sidestepping sport tasks. Following data collection, participants were classified as possessing a habitual RF or FF fall pattern during UnSS. Hip, knee and ankle joint angles, moments, instantaneous powers and net joint work were calculated during weight acceptance. Between group differences were evaluated using independent s le t-tests (α=0.05). Athletes using a habitual RF fall pattern during UnSS absorbed significantly more work and power through their knee joint (p<0.001), which was coupled with significantly elevated externally applied peak non-sagittal plane peak ankle moments (p<0.05) as well as peak flexion and abduction knee moments (p<0.005). Athletes using a habitual FF fall pattern during UnSS absorbed more power through their ankle joint (p<0.001). A RF fall pattern during UnSS places a large mechanical demand on the knee joint, which is associated with elevated ACL injury risk. Conversely, a FF fall pattern placed a large mechanical demand on the ankle joint. Modifying an athlete's foot fall pattern during UnSS may be viable technique recommendation when returning from knee or ankle injury.
Publisher: Informa UK Limited
Date: 2007
DOI: 10.1080/14763140601058623
Abstract: In cricket bowling, the reconstruction of elbow angle data is of utmost importance to the bowling versus throwing argument. This paper reviews system and modelling errors inherent in three-dimensional reconstruction processes with respect to the elbow extension tolerance set by the International Cricket Council. An understanding of these factors will enable more informed decisions about the choice of in-field versus laboratory testing in the calculation of elbow extension during bowling in cricket. Although there is a paucity of objective data related to in-field and laboratory testing, biomechanists must be guided by the greater accuracy of opto-reflective than video-based systems and so testing, at least for the present, should be conducted in a laboratory setting.
Publisher: Informa UK Limited
Date: 18-04-2016
DOI: 10.1080/14763141.2016.1163413
Abstract: The aim of this study was to compare the associations between lower limb biomechanics and ball release speed in 15 high-performance (HP) and 15 amateur fast bowlers. Kinematic and kinetic variables of the lower limbs collected in the laboratory environment with a 3D Vicon motion analysis system were compared between groups, as well as their associations with ball release speed. HP bowlers had a significantly higher run-up velocity at back foot impact but this difference became non-significant at ball release. Front knee kinematics were not statistically different, however effect sizes revealed medium-large differences with the HP group displaying a more extended knee joint at maximum flexion (d = 0.72) and ball release (d = 0.76). Only front hip positive power was significantly higher in the HP group and it was suggested that the probable cause was the HP bowlers having less knee flexion after front foot impact. From a joint power analysis, the extensor muscle groups of the hip and knee were shown to be important in developing ball release speed. This highlights the need for lower limb/core strength programmes to be multifaceted and focus on the muscles associated with both power and stability.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2013
Publisher: Georg Thieme Verlag KG
Date: 14-06-2018
DOI: 10.1055/A-0592-7422
Abstract: Unplanned sidestepping and single-leg landing have both been used to screen athletes for injury risk in sport. The aim of this study was to directly compare the lower limb mechanics of three single-leg landing tasks and an unplanned sidestepping task. Thirteen elite female team sport athletes completed a series of non-contact single-leg drop landings, single-leg countermovement jumps, single-leg jump landings and unplanned sidestepping in a randomized counterbalanced design. Three dimensional kinematics (250 Hz) and ground reaction force (2,000 Hz) data with a participant specific lower limb skeletal model were used to calculate and compare hip, knee and ankle joint kinematics, peak joint moments, instantaneous joint power and joint work during the weight acceptance phase of each sporting task (α=0.05). Peak knee joint moments and relevant injury risk thresholds were used to classify each athlete's anterior cruciate ligament injury risk during unplanned sidestepping and single-leg jump landing. Results showed that peak joint moments, power and work were greater during the single-leg jump landing task when compared to the single-leg drop landings and single-leg countermovement jumps tasks. Peak frontal and sagittal plane knee joint moments, knee joint power, as well as hip and knee joint work were greater during unplanned sidestepping when compared to the landing tasks. Peak ankle joint moments, power and work were greater during the landing tasks when compared to unplanned sidestepping. For 4 of the 13 athletes tested, their anterior cruciate ligament injury risk classification changed depending on whether they performed an unplanned sidestepping or single-leg jump landing testing procedure. To summarize, a single-leg jump landing testing procedure places a larger mechanical on the ankle joint when compared to single-leg drop landings, single-leg countermovement jumps and unplanned sidestepping. An unplanned sidestepping testing procedure places a larger mechanical demand on the knee joint when compared to single-leg landing tasks. Both unplanned sidestepping and single-leg jump landing testing procedures are recommended for classifying an athlete's anterior cruciate ligament injury risk in sport.
Publisher: Informa UK Limited
Date: 14-11-2019
DOI: 10.1080/02640414.2019.1692997
Abstract: Accelerometers are often placed on the tibia to measure segmental accelerations, and external mechanical load during running. However, in applied sport settings it is sometimes preferable to place accelerometers on the dorsal foot to avoid tibial impact injuries. This study aimed to quantify the differences in accelerations measured at the dorsal foot compared with the distal tibia during running. Sixteen recreationally active participants performed a sprint protocol on a non-motorised treadmill. Accelerometers were positioned bilaterally on the medial tibia (TIB
Publisher: Wiley
Date: 05-11-2019
DOI: 10.1111/SMS.13571
Abstract: There is strong evidence linking an athlete's movement technique during sidestepping with anterior cruciate ligament (ACL) injury risk. However, it is unclear how these injurious postures are influenced by prior movement. We aim to describe preparatory trunk and thigh kinematics at toe-off of the penultimate-step and flight-phase angular momenta, and explore their associations with frontal-plane risk factors during unplanned sidestepping maneuvers. We analyzed kinematic and kinetic data of 33 male Australian Football players performing unplanned sidestepping tasks (103 trials). Linear mixed models tested for reliable associations between ACL injury risk during weight acceptance of the execution-step, with preparatory kinematics and angular momenta of the trunk and thigh during the penultimate-step. Multi-planar flight-phase trunk momenta along with hip abduction angle at penultimate-step toe-off were significantly associated with peak knee valgus moments during the execution-step (R
Publisher: MDPI AG
Date: 21-12-2022
DOI: 10.3390/S23010078
Abstract: The adoption of computer vision pose estimation approaches, used to identify keypoint locations which are intended to reflect the necessary anatomical landmarks relied upon by biomechanists for musculoskeletal modelling, has gained increasing traction in recent years. This uptake has been further accelerated by keypoint use as inputs into machine learning models used to estimate biomechanical parameters such as ground reaction forces (GRFs) in the absence of instrumentation required for direct measurement. This study first aimed to investigate the keypoint detection rate of three open-source pose estimation models (AlphaPose, BlazePose, and OpenPose) across varying movements, camera views, and trial lengths. Second, this study aimed to assess the suitability and interchangeability of keypoints detected by each pose estimation model when used as inputs into machine learning models for the estimation of GRFs. The keypoint detection rate of BlazePose was distinctly lower than that of AlphaPose and OpenPose. All pose estimation models achieved a high keypoint detection rate at the centre of an image frame and a lower detection rate in the true sagittal plane camera field of view, compared with slightly anteriorly or posteriorly located quasi-sagittal plane camera views. The three-dimensional ground reaction force, instantaneous loading rate, and peak force for running could be estimated using the keypoints of all three pose estimation models. However, only AlphaPose and OpenPose keypoints could be used interchangeably with a machine learning model trained to estimate GRFs based on AlphaPose keypoints resulting in a high estimation accuracy when OpenPose keypoints were used as inputs and vice versa. The findings of this study highlight the need for further evaluation of computer vision-based pose estimation models for application in biomechanical human modelling, and the limitations of machine learning-based GRF estimation models that rely on 2D keypoints. This is of particular relevance given that machine learning models informing athlete monitoring guidelines are being developed for application related to athlete well-being.
Publisher: SAGE Publications
Date: 22-12-2021
Publisher: IEEE
Date: 06-2013
Publisher: Springer Science and Business Media LLC
Date: 09-01-2021
DOI: 10.1186/S40798-020-00292-5
Abstract: To examine the test re-test reliability of isometric maximal voluntary contractions (MVC) of hip adduction (ADD ISO ), hip abduction (ABD ISO ), and multijoint leg extension (SQUAT ISO ) in sub-elite female Australian footballers. Data were collected from 24 sub-elite female Australian footballers (age 22.6 ± 4.5 years height 169.4 ± 5.5 cm body mass 66.6 ± 8.0 kg 4.5 ± 4.4 years sport-specific training 2.5 ± 2.0 years unstructured resistance training) from the same club on two non-consecutive days. Participants performed three isometric MVCs of ADD ISO , ABD ISO , and SQUAT ISO . The SQUAT ISO was performed at 140° knee flexion with a vertical trunk position and ADD ISO and ABD ISO measures were performed in a supine position at 60° of knee flexion and 60° hip flexion. Reliability was assessed using paired t tests and the intraclass correlation coefficient (ICC) with 95% confidence intervals (CI), typical error (TE), and coefficient of variation (CV%) with 95% CI. SQUAT ISO peak force (ICC .95 CV% 4.1), ABD ISO for left, right, and sum (ICC .90–.92 CV% 5.0–5.7), and ADD ISO for left, right, and sum (ICC .86–.91 CV% 6.2–6.9) were deemed acceptably reliable based on predetermined criteria (ICC ≥ .8 and CV% ≤ 10). SQUAT ISO , ABD ISO , and ADD ISO tests demonstrated acceptable reliability for the assessment of peak force in sub-elite female Australian footballers, suggesting these assessments are suitable for muscle strength testing and monitoring adaptations to training.
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.GAITPOST.2021.11.012
Abstract: There is a range of magneto-inertial measurement unit (MIMU) systems commercially available, however sensor specifications and fusion methods vary considerably between manufacturers. Such variability can influence the concurrent validity of MIMUs relative to reference standard measurement devices. Different MIMUs have been compared during static or low-velocity conditions, with higher-velocity movements assessed in robotic-based studies. However, there is a need for the concurrent validity of higher-velocity movements to be established in human-based studies. This study aimed to assess the concurrent validity of two commercial MIMU systems (Noraxon and Xsens), relative to a 'gold-standard' retro-reflective motion capture system, when measuring trunk angles during uni-planar range of motion (ROM) and cricket bowling, which involves high-speed, multi-planar movements. For this criterion-based validity study, both MIMU systems incorporated comparable sensor specifications and employed Kalman filter sensor fusion algorithms. The MIMU based angles were compared with angles derived from concurrently captured three-dimensional retro-reflective data for 10 fast-medium bowlers. Statistical parametric mapping and root mean squared differences (RMSD) were computed for both MIMU systems. One-dimensional statistical parametric mapping showed no significant differences for angles from both MIMU systems when compared with retro-reflective based angle outputs. The MIMU systems produced ROM RMSDs between 1.4 ± 1.0° and 2.6 ± 1.5°. One system displayed RMSDs between 4.6 ± 1.4° and 7.4 ± 1.9° during bowling, indicating functionally relevant differences to retro-reflective derived angles. There were some small but statistically significant differences in RMSDs between the MIMU systems. MIMU-based angle accuracy is poorer during high-speed, multi-planar movement than uni-planar tasks. Comparable MIMU systems can produce varying measurements during ROM and bowling tasks. It is likely that varying s le rates and sensor fusion algorithm parameters contributed to the differences.
Publisher: PeerJ
Date: 23-06-2020
DOI: 10.7717/PEERJ.9366
Abstract: Quantifying lower-limb load and asymmetry during team sport match-play may be important for injury prevention and understanding performance. However, current analysis methods of lower-limb symmetry during match-play employ wearable microtechnology that may not be best suited to the task. A popular microtechnology is global positioning systems (GPS), which are torso worn. The torso location, and the summary workload measures calculated by GPS are not suited to the calculation of lower-limb load. Instead, research grade accelerometers placed directly on the lower-limb may provide better load information than GPS. This study proposes a new technique to quantify external mechanical load, and lower-limb asymmetry during on-field team sport play using inertial measurement units. Four professional rugby league players (Age: 23.4 ± 3.1 years Height: 1.89 ± 0.05 m Mass: 107.0 ± 12.9 kg) wore two accelerometers, one attached to each foot by the boot laces, during match simulations. Custom Matlab (R2017b, The Mathworks Inc, Natick, MA) code was used to calculate total time, area under the curve (AUC), and percentage of time (%Time) spent in seven acceleration categories (negative to very high, g to g), as well as minimum and maximum acceleration during match simulations. Lower-limb AUC and %Time asymmetry was calculated using the Symmetry Angle Equation, which does not require normalization to a reference leg. The range of accelerations experienced across all participants on the left and right sides were 15.68–17.53 g, and 16.18–17.69 g, respectively. Clinically significant asymmetry in AUC and %Time was observed for all but one participant, and only in negative ( g) and very high accelerations ( g). Clinically significant AUC differences in very high accelerations ranged from 19.10%–26.71%. Clinically significant %Time differences in negative accelerations ranged from 12.65%–25.14%, and in very high accelerations from 18.59%–25.30%. All participants experienced the most AUC at very low accelerations (2–4 g), and the least AUC at very high accelerations (165.00–194.00 AU vs. 0.32–3.59 AU). The %Time results indicated that all participants spent the majority of match-play (73.82–92.06%) in extremely low (0–2 g) to low (4–6 g) acceleration intensities, and the least %Time in very high accelerations (0.01%–0.05%). A wearable located on the footwear to measure lower-limb load and asymmetry is feasible to use during rugby league match-play. The location of the sensor on the boot is suited to minimize injury risk occurring from impact to the sensor. This technique is able to quantify external mechanical load and detect inter limb asymmetries during match-play at the source of impact and loading, and is therefore likely to be better than current torso based methods. The results of this study may assist in preparing athletes for match-play, and in preventing injury.
Publisher: Elsevier BV
Date: 11-2018
Start Date: 2011
End Date: 12-2014
Amount: $254,329.00
Funder: Australian Research Council
View Funded Activity