ORCID Profile
0000-0002-4599-8439
Current Organisations
The Univeristy of Queensland
,
Queensland University of Technology
,
Griffith University
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Publisher: Elsevier BV
Date: 10-2017
DOI: 10.1016/J.GAITPOST.2017.07.108
Abstract: Foot structure has been implicated as a risk factor of numerous overuse injuries, however, the mechanism linking foot structure and the development of soft-tissue overuse injuries are not well understood. The aim of this study was to identify factors that could predict foot function during walking. A total of eleven variables (including measures of foot structure, anthropometry and spatiotemporal gait characteristics) were investigated for their predictive ability on identifying kinematic, kinetic and energetic components of the foot. Three-dimensional motion capture and force data were collected at preferred walking speed on an instrumented treadmill. Mechanical measures were subsequently assessed using a custom multi-segment foot model in Opensim. Factors with significant univariate associations were entered into multiple linear regression models to identify a group of factors independently associated with the mechanical measures. Although no model could be created for any of the kinematic measures analysed, approximately 46% and 37% of the variance in the kinetic and energetic measures were associated with three or two factors respectively. Arch-height ratio, foot length and step width were associated with peak subtalar joint (STJ) moment, while greater STJ negative work was correlated to a low arch-height ratio and greater foot mobility. The models presented in this study suggest that the soft-tissue structures of a flat-arched, mobile foot are at a greater risk of injury as they have greater requirements to absorb energy and generate larger forces. However, as these associations are only moderate, other measures may also have an influence.
Publisher: Frontiers Media SA
Date: 10-03-2020
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 03-2020
Publisher: Elsevier BV
Date: 02-2023
Publisher: PeerJ
Date: 04-02-0100
DOI: 10.7717/PEERJ.8397
Abstract: Musculoskeletal models are important tools for studying movement patterns, tissue loading, and neuromechanics. Personalising bone anatomy within models improves analysis accuracy. Few studies have focused on personalising foot bone anatomy, potentially incorrectly estimating the foot’s contribution to locomotion. Statistical shape models have been created for a subset of foot-ankle bones, but have not been validated. This study aimed to develop and validate statistical shape models of the functional segments in the foot: first metatarsal, midfoot (second-to-fifth metatarsals, cuneiforms, cuboid, and navicular), calcaneus, and talus then, to assess reconstruction accuracy of these shape models using sparse anatomical data. Magnetic resonance images of 24 in iduals feet (age = 28 ± 6 years, 52% female, height = 1.73 ± 0.8 m, mass = 66.6 ± 13.8 kg) were manually segmented to generate three-dimensional point clouds. Point clouds were registered and analysed using principal component analysis. For each bone segment, a statistical shape model and principal components were created, describing population shape variation. Statistical shape models were validated by assessing reconstruction accuracy in a leave-one-out cross validation. Statistical shape models were created by excluding a participant’s bone segment and used to reconstruct that same excluded bone using full segmentations and sparse anatomical data (i.e. three discrete points on each segment), for all combinations in the dataset. Tali were not reconstructed using sparse anatomical data due to a lack of externally accessible landmarks. Reconstruction accuracy was assessed using Jaccard index, root mean square error (mm), and Hausdorff distance (mm). Reconstructions generated using full segmentations had mean Jaccard indices between 0.77 ± 0.04 and 0.89 ± 0.02, mean root mean square errors between 0.88 ± 0.19 and 1.17 ± 0.18 mm, and mean Hausdorff distances between 2.99 ± 0.98 mm and 6.63 ± 3.68 mm. Reconstructions generated using sparse anatomical data had mean Jaccard indices between 0.67 ± 0.06 and 0.83 ± 0.05, mean root mean square error between 1.21 ± 0.54 mm and 1.66 ± 0.41 mm, and mean Hausdorff distances between 3.21 ± 0.94 mm and 7.19 ± 3.54 mm. Jaccard index was higher ( P 0.01) and root mean square error was lower ( P 0.01) in reconstructions from full segmentations compared to sparse anatomical data. Hausdorff distance was lower ( P 0.01) for midfoot and calcaneus reconstructions using full segmentations compared to sparse anatomical data. For the first time, statistical shape models of the primary functional segments of the foot were developed and validated. Foot segments can be reconstructed with minimal error using full segmentations and sparse anatomical landmarks. In future, larger training datasets could increase statistical shape model robustness, extending use to paediatric or pathological populations.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2018
DOI: 10.1249/MSS.0000000000001591
Abstract: Foot orthoses maybe used in the management of musculoskeletal disorders related to abnormal subtalar joint (STJ) pronation. However, the precise mechanical benefits of foot orthoses for preventing injuries associated with the STJ are not well understood. The aim of this study was to investigate the immediate effect of foot orthoses on the energy absorption requirements of the STJ and subsequently tibialis posterior (TP) muscle function. Eighteen asymptomatic subjects with a pes planus foot posture were prescribed custom-made foot orthoses made from a plaster cast impression. Participants walked at preferred and fast velocities barefoot, with athletic footwear and with athletic footwear plus orthoses, as three-dimensional motion capture, force data, and intramuscular electromyography of the TP muscle were simultaneously collected. Statistical parametric mapping was used to identify time periods across the stride cycle during which footwear with foot orthoses significantly differed to barefoot and footwear only. During early stance, footwear alone and footwear with orthoses significantly reduced TP muscle activation (1%–12%), supination moments (3%–21%), and energy absorption (5%–12%) at the STJ, but had no effect on STJ pronation displacement. The changes in TP muscle activation and STJ energy absorption were primarily attributed to footwear because the addition of foot orthoses provided little additional effect. We speculate that these results are most likely a result of the compliant material properties of footwear. These results suggest that athletic footwear may be sufficient to absorb energy in the frontal plane and potentially reducing any benefit associated with the addition of foot orthoses.
Publisher: Human Kinetics
Date: 08-2022
Abstract: Humans have the remarkable ability to run over variable terrains. During locomotion, however, humans are unstable in the mediolateral direction and this instability must be controlled actively—a goal that could be achieved in more ways than one. Walking research indicates that the subtalar joint absorbs energy in early stance and returns it in late stance, an attribute that is credited to the tibialis posterior muscle-tendon unit. The purpose of this study was to determine how humans (n = 11) adapt to mediolateral perturbations induced by custom-made 3D-printed “footwear” that either enhanced or reduced pronation of the subtalar joint (modeled as motion in 3 planes) while running (3 m/s). In all conditions, the subtalar joint absorbed energy (ie, negative mechanical work) in early stance followed by an immediate return of energy (ie, positive mechanical work) in late stance, demonstrating a “spring-like” behavior. These effects increased and decreased in footwear conditions that enhanced or reduced pronation ( P ≤ .05), respectively. Of the recorded muscles, the tibialis posterior ( P ≤ .05) appeared to actively change its activation in concert with the changes in joint energetics. We suggest that the “spring-like” behavior of the subtalar joint may be an inherent function that enables the lower limb to respond to mediolateral instabilities during running.
Publisher: Springer Science and Business Media LLC
Date: 20-12-2017
DOI: 10.1038/S41598-017-17771-7
Abstract: During human walking, the tibialis posterior (TP) tendon absorbs energy in early stance as the subtalar joint (STJ) pronates. However, it remains unclear whether an increase in energy absorption between in iduals, possibly a result of larger STJ pronation displacement, is fulfilled by greater magnitudes of TP tendon or muscle fascicle strain. By collecting direct measurements of muscle fascicle length (ultrasound), MTU length (3D motion capture and musculoskeletal modelling), and TP muscle activation (intramuscular electromyography) we endeavoured to illustrate that the TP tendinous tissue fulfils the requirements for energy absorption at the STJ as a result of an increase in muscle force production. While a significant relationship between TP tendon strain, energy absorption at the STJ (R 2 = 0.53, P = 0.01) and STJ pronation (R 2 = 0.53, P = 0.01) was evident, we failed to find any significant associations between tendon strain and surrogate measure of TP muscle force (TP muscle activation together with ankle and subtalar joint moments). These results suggest that TP tendon compliance may explain the variance in pronation and energy absorption at the STJ. Therefore, as the tendinous tissue of the TP is accountable for the absorption of energy at the STJ it may be predisposed to strain-induced injury.
Publisher: Elsevier BV
Date: 06-2023
Publisher: BMJ
Date: 07-2019
DOI: 10.1136/BMJOPEN-2018-026240
Abstract: Peripheral neuropathy is a major risk factor for falls in adults with diabetes. Innovative footwear devices which artificially manipulate the sensory environment at the feet, such as textured shoe insoles, are emerging as an attractive option to mitigate balance and walking problems in neuropathic populations. This study aims to explore whether wearing textured insoles for 4 weeks alters balance performance in adults with diabetic peripheral neuropathy. A prospective, single-blinded randomised controlled trial with parallel groups will be conducted on 70 adults with diabetic peripheral neuropathy. Adults with a diagnosis of peripheral neuropathy (secondary to type 2 diabetes), aged ≥18 years, ambulant over 20 m (with/without an assistive device), will be recruited. Participants will be randomised to receive a textured insole (n=35) or smooth insole (n=35), to be worn for 4 weeks. During baseline and post intervention assessments, standing balance (foam/firm surface eyes open/closed) and walking tasks will be completed barefoot, wearing standard shoes only, and two different insoles (smooth, textured). The primary outcome measure will be centre of pressure (CoP) velocity, with higher values indicating poorer balance. Secondary outcome measures include walking quality (gait velocity, base of support, stride length and double-limb support time), physical activity levels, foot sensation (light-touch pressure, vibration) and proprioception (ankle joint position sense), and other balance parameters (CoP path length, anteroposterior and mediolateral excursion). Patient-reported outcomes will be completed evaluating foot health, frequency of falls and fear of falling. Data will be analysed using a repeated measures mixed models approach (including covariates) to establish any differences between-groups, for all outcome measures, over the intervention period. Ethical approval has been obtained from the institutional Human Research Ethics Committee (#2017000098). Findings will be disseminated at national and international conferences, through peer-reviewed journals, workshops and social media. ACTRN12617000543381 Pre-results.
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: 05-2022
Publisher: University of Queensland Library
Date: 2018
Publisher: Elsevier BV
Date: 11-2017
Publisher: Informa UK Limited
Date: 15-09-2022
Publisher: Cambridge University Press (CUP)
Date: 20-12-2023
Abstract: Innovative shoe insoles, designed to enhance sensory information on the plantar surface of the feet, could help to improve walking in people with Multiple Sclerosis. To compare the effects of wearing textured versus smooth insoles, on measures of gait, foot sensation and patient-reported outcomes, in people with Multiple Sclerosis. A prospective, randomised controlled trial was conducted with concealed allocation, assessor blinding and intention-to-treat analysis. Thirty ambulant men and women with multiple sclerosis (MS) (Disease Steps rating 1–4) were randomly allocated to wear textured or smooth insoles for 12 weeks. Self-reported insole wear and falls diaries were completed over the intervention period. Laboratory assessments of spatiotemporal gait patterns, foot sensation and proprioception, and patient-reported outcomes, were performed at Weeks 0 (Baseline 1), 4 (Baseline 2) and 16 (Post-Intervention). The primary outcome was the size of the mediolateral base of support (stride/step width) when walking over even and uneven surfaces. Independent t -tests were performed on change from baseline (average of baseline measures) to post-intervention. There were no differences in stride width between groups, when walking over the even or uneven surfaces ( P ≥ 0.20) at post-intervention. There were no between-group differences for any secondary outcomes including gait (all P values 0.23), foot sensory function (all P values ≥ 0.08) and patient-reported outcomes (all P values ≥ 0.23). In our small trial, prolonged wear of textured insoles did not appear to alter walking or foot sensation in people with MS who have limited foot sensory loss. Further investigation is needed to explore optimal insole design. Australian and New Zealand Clinical Trials Registry (ACTRN12615000421538).
Publisher: Elsevier BV
Date: 07-2019
DOI: 10.1016/J.JBIOMECH.2019.05.021
Abstract: The subtalar joint (STJ) contributes to the absorption and generation of mechanical energy (and power) during walking to maintain frontal plane stability. Previous observational studies have suggested that there may be a relationship between step width and STJ supination moment. This study directly tests the hypothesis that walking with a step width greater than preferred would reduce STJ moments, energy absorption, and power generation requirements, while increasing energy absorption at the hip during initial contact. Participants (n = 12, 7 females) were asked to walk on an instrumented treadmill at a constant velocity and cadence at a range of fixed step widths ranging from 0.1 to 0.4 times leg length (L). Walking at step widths greater than preferred (0.149 ± 0.04 L) reduced peak STJ moments at initial contact and propulsion which subsequently reduced the negative and positive work performed at the STJ. There was a 43% reduction in energy absorption (negative work) and approximately 30% decrease in positive work at the STJ as step width increased from 0.1 L to 0.4 L. An increase in energy absorption at the knee and hip was evident with an increase in step width during initial contact, although minimal mechanical changes were observed at the proximal joints during propulsion. These results suggest an increase in step width reduces the forces generated by muscles at the STJ across stance and is therefore likely to be beneficial in the prevention and treatment of their injuries. In terms of rehabilitation, the increase in mechanical costs occurring due to an increase in energy absorption by the hip and knee is of minimal concern.
Publisher: Informa UK Limited
Date: 26-10-2021
DOI: 10.1080/10255842.2021.1968844
Abstract: We developed and validated a multi-segment foot and ankle model for human walking and running. The model has 6-segments, and 7 degrees of freedom motion between foot segments were constrained with a single oblique axis to enable triplanar motion [Joint Constrained (JC) model]. The accuracy of the JC model and that of a conventional model using a 6 degrees of freedom approach were assessed by comparison to segment motion determined with biplanar videoradiography. Compared to the 6-DoF model, our JC model demonstrated significantly smaller RMS differences [JC: 2.19° (1.43-2.73) 6-DoF: 3.25° (1.37-5.89)] across walking and running. The JC model is thus capable of more accurate musculoskeletal analyses and is also well suited for predictive simulations.
Publisher: Public Library of Science (PLoS)
Date: 19-11-2021
DOI: 10.1371/JOURNAL.PONE.0256528
Abstract: Rupture of the scapholunate interosseous ligament can cause the dissociation of scaphoid and lunate bones, resulting in impaired wrist function. Current treatments (e.g., tendon-based surgical reconstruction, screw-based fixation, fusion, or carpectomy) may restore wrist stability, but do not address regeneration of the ruptured ligament, and may result in wrist functional limitations and osteoarthritis. Recently a novel multiphasic bone-ligament-bone scaffold was proposed, which aims to reconstruct the ruptured ligament, and which can be 3D-printed using medical-grade polycaprolactone. This scaffold is composed of a central ligament-scaffold section and features a bone attachment terminal at either end. Since the ligament-scaffold is the primary load bearing structure during physiological wrist motion, its geometry, mechanical properties, and the surgical placement of the scaffold are critical for performance optimisation. This study presents a patient-specific computational biomechanical evaluation of the effect of scaffold length, and positioning of the bone attachment sites. Through segmentation and image processing of medical image data for natural wrist motion, detailed 3D geometries as well as patient-specific physiological wrist motion could be derived. This data formed the input for detailed finite element analysis, enabling computational of scaffold stress and strain distributions, which are key predictors of scaffold structural integrity. The computational analysis demonstrated that longer scaffolds present reduced peak scaffold stresses and a more homogeneous stress state compared to shorter scaffolds. Furthermore, it was found that scaffolds attached at proximal sites experience lower stresses than those attached at distal sites. However, scaffold length, rather than bone terminal location, most strongly influences peak stress. For each scaffold terminal placement configuration, a basic metric was computed indicative of bone fracture risk. This metric was the minimum distance from the bone surface to the internal scaffold bone terminal. Analysis of this minimum bone thickness data confirmed further optimisation of terminal locations is warranted.
Publisher: The Company of Biologists
Date: 2019
DOI: 10.1242/JEB.191247
Abstract: The elastic tendinous tissues of distal lower limb muscles can improve the economy of walking and running, lify the power generated by a muscle as well as absorb energy. This paper explores the behaviour of the tibialis anterior (TA) muscle and its tendinous tissue during gait, as it absorbs energy during contact and controls foot position during swing. Simultaneous measurements of ultrasound, surface electromyography and 3-dimensional motion capture with musculoskeletal modelling from twelve healthy participants were recorded as they walked at preferred and fast walking speeds. We quantified the length changes and velocities of the TA muscle-tendon unit and its fascicles across the stride at each speed. Fascicle length changes and velocities were relatively consistent across speeds, although the magnitude of fascicle length change differed between the deep and superficial regions. At contact, when the TA is actively generating force, the fascicles remained relatively isometric as the MTU actively lengthened, presumably stretching the TA tendinous tissue and absorbing energy. This potentially protects the muscle fibres from damage during weight acceptance and allows energy to be returned to the system later in the stride. During early swing the fascicles and MTU both actively shortened to dorsiflex the foot, clearing the toes from the ground although, at the fast walking velocity the majority of the shortening occurred through tendinous tissue recoil, highlighting its role in accelerating ankle dorsi-flexion to power rapid foot clearance in swing.
Publisher: Elsevier BV
Date: 10-2016
DOI: 10.1016/J.JBIOMECH.2016.08.006
Abstract: The tibialis posterior (TP) muscle is believed to provide mediolateral stability of the subtalar joint during the stance phase of walking as it actively lengthens to resist pronation at foot contact and then actively shortens later in stance to contribute to supination. Because of its anatomical structure of short muscle fibres and long series elastic tissue, we hypothesised that TP would be a strong candidate for energy storage and return. We investigated the potential elastic function of the TP muscle and tendon through simultaneous measurements of muscle fascicle length (ultrasound), muscle tendon unit length (musculoskeletal modelling) and muscle activation (intramuscular electromyography). In early stance, TP fascicles actively shortened as the entire muscle-tendon unit lengthened, resulting in the absorption of energy through stretch of the series elastic tissue. Energy stored in the tendinous tissue from early stance was maintained during mid-stance, although a small amount of energy may have been absorbed via minimal shortening in the series elastic elements and lengthening of TP fascicles. A significant amount of shortening occurred in both the fascicles and muscle-tendon unit in late stance, as the activation of TP decreased and power was generated. The majority of the shortening was attributable to shortening of the tendinous tissue. We conclude that the tendinous tissue of TP serves two primary functions during walking: 1) to buffer the stretch of its fascicles during early stance and 2) to enhance the efficiency of the TP through absorption and return of elastic strain energy.
Publisher: Elsevier BV
Date: 11-2017
No related grants have been discovered for Jayishni Maharaj.