A step in the right direction: Delphi consensus on a UK and Australian paediatric podiatry curriculum.

BACKGROUND: Previous research shows considerable variation in pre-registration paediatric podiatry curricula, and thus the clinical skills realised prior to graduation. Whilst pre-registration training is guided by regulatory bodies, these high level principles only refer briefly to standards in paediatric practice. An estimated 9% of podiatry caseloads in the United Kingdom (UK) and Australia are dedicated to paediatric service provision. Therefore, it is imperative that curricula support the consistent development of paediatric practice enabling newly registered podiatrists to work safely and effectively with children. Given that the global healthcare work force provides unique opportunities to explicitly align international curricula, the aim of this study was to determine the priorities for a UK and Australian binational pre-registration paediatric podiatry curriculum. METHODS: A four round modified Delphi design was employed to ascertain consensus and agreement of a panel of experts with a special interest in paediatrics working in the UK and Australia. Round 1 contained open questions designed to promote diverse responses on the broad topics of lecturer experience and curriculum organisation and delivery. The answers from Round 1 were developed, through content analysis, into a series of statements presented to the panel for agreement in Rounds 2, 3 and 4. RESULTS: Of the 297 statements generated following Round 1, 183 were accepted and 114 rejected by the end of Round 4. 109 of the accepted statements related to curriculum content. Participants also agreed on areas relating to lecturer experience, clinical education, and assessment of paediatric skills. CONCLUSIONS: This study is the first of its kind to describe elements of a curriculum for pre-registration podiatry training. The recommendations highlight opportunities that education providers can work towards during curriculum design. They also emphasise the collaboration that is needed between professional bodies, clinicians and higher education institutions when defining guidelines and expectations for paediatric specific skills.

Longitudinal study of foot pressures during real-world walking as infants develop from new to confident walkers.

BACKGROUND: Onset of walking in infants leads to regular cyclic loading of the plantar foot surface for the first time. This is a critical period for evolving motor skills and foot structure and function. Plantar pressure literature typically studies gait only once walking is established and under conditions that artificially constrain the walking direction and bouts compared to how infants move in the real-world. We therefore do not know how the foot is loaded when self-directed walking is first achieved and whether it changes as walking is practiced. Research question How do pressures on the plantar foot in real-world walking change from new to confident walking? Methods Fifty-seven infants participated in a two-site longitudinal study. Bespoke child-friendly spaces incorporated large pressure platforms and video. Data was collected at two milestones: new (403 days) and confident (481 days) walking. Steps were defined as walking straight or turning medially/laterally. Pressure variables were calculated for eight-foot regions and compared between milestones. Results Confident walking resulted in more steps (median: 18 v 35) and almost twice as many turning steps. During straight-line steps, confident walking increased peak pressures in the medial heel (median: 99.3 v 106.7kPa, p < .05) and lateral forefoot (median: 53.9 v 65.3kPa, p < .001) and reduced medial toe pressure (median: 98.1 v 80.0kPa, p < .05). Relative medial midfoot contact area reduced (median: 12.4 v 11.2%, p < .05) as absolute foot contact increased. A faster transition across stance and a reduced relative contact time in the forefoot were recorded in confident walking. Significance Pressures change rapidly as walking is initiated with significant differences in foot loading evident within an average 77 days. Importantly, these changes differ in straight and turning walking. Continued reliance on assessment of straight-line walking during early stages of ambulation likely fails to characterise 26% of steps experienced by infant feet.

Dynamic Characteristics of Foot Development: A Narrative Synthesis of Plantar Pressure Data During Infancy and Childhood.

PURPOSE: Quantifying plantar pressure throughout childhood enables clinicians to enhance knowledge of typical changes in foot function. This narrative review aims to describe existing research reporting plantar pressure analysis in infants and children developing typically, to advance understanding of foot development. METHODS: A narrative approach was used; 263 articles were identified and 13 met inclusion criteria. RESULTS: Plantar pressures during walking rapidly change in infancy and childhood. With development, pressures increasingly resemble those in adults with the development of initial heel contact, shift in pressure distribution from medial to lateral foot side, decreasing midfoot pressure magnitude. The literature has a variety of study designs, data collection protocols, and analysis. CONCLUSION: This review describes plantar pressure changes occurring as walking develops, emphasizing the typical trajectory of foot function development in infancy and childhood. The present finding describes the complex biomechanical development of foot function in typically developing infancy and childhood.

The biopsychosocial-digital continuum of foot orthosis practice and research: the VALUATOR model.

Foot orthoses have been used for decades despite uncertainty surrunding their therapeutic efficacy. Orthoses have been used exclusively to affect neuro-biomechanical input and outcome variables, however, there is emerging evidence that therapeutic efficacy may be affected by a psychological stimulus. Critical appraisal of the literature highlights that there is no holistic model upon which foot orthosis practice is taught, practised nor investigated. This paper introduces a conceptual model of foot orthosis practice (Value Based Foot Orthosis Practice (VALUATOR) model) that embraces a broader range of factors that are pertinent to orthosis practice, incorporating contemporary health service behaviours and values into orthosis practice for the first time.Within the VALUATOR model, foot orthosis design and clinical value is considered along a bio-psycho-social-digital continuum that reflects the reality of foot orthosis practice. The model contextualises the variable outcomes that are observed in research and practice within 6 key areas: 1) value, 2) person-centered approach, 3) zone of optimal bio-psycho-social stress, 4) bio-psycho-social assessment, 5) monitoring, 6) primary and secondary clinical strategies.The VALUATOR model is targeted at students, lecturers, scientists and practitioners and includes carefully chosen terminology to support a robust basis for educational and scientific discussion. It is believed that it provides a contemporary viewpoint and a structured conceptual metaphor that builds on existing evidence from a wide range of sources, invites constructive intellectual debate, and is anchored in the experiences of practitioners too. Stress testing the VALUATOR model will help determine its model and support further developments and evolution of orthotic practice in a evidence based way.

A conceptual framework for contemporary professional foot care practice: ''The value based digital foot care framework''.

BACKGROUND: A small minority of countries around the globe have podiatry as a recognized profession, hence, there are considerable differences among these countries when it comes to the curricula, the duration of training and legislation regulating the profession. The growth in research led evidence based practice, and the emerging digital landscape of health care practice, occur alongside trends in disease and health behaviours that strongly impact on foot health. As such, the changing complex role of the podiatrist requires critical reflection on current frameworks of practice and whether they are fit for purpose. This commentary presents a conceptual framework which sets the scene for further development of concepts in a podiatry context, reflecting contemporary health care beliefs and the changing expectations of health care and society. The proposed conceptual framework for podiatry practice utilizes the metaphor of an electronic circuit to reflect the vast and complex interconnections between factors that affect practice and professional behaviours. The framework helps in portraying and defining drivers of practice, actual practice as well potential barriers for current and future practice. The circuit emphasis the interconnectedness/interaction of three clusters: 1) internal factors, 2) interaction factors, 3) external factors. CONCLUSION: Whatever promise this new framework holds, it will only be realised through conscious development of community consensus, respectful dialogue, constructive critical appraisal, and maintaining passion and focus on improving the health of people with foot related problems.

Effects of intermittent claudication due to arterial disease on pain-free gait.

INTRODUCTION: Studies of intermittent claudication gait report inconsistent outcomes. Changes in gait are often attributed to degradation of calf muscles, but causation has not been proven through real-time electromyographic data. Neither have effects of walking speed been fully considered. This study aimed to investigate the effect of intermittent claudication on kinematics, kinetics and muscle activity during pain-free gait. METHODS: 18 able bodied individuals and 18 with intermittent claudication walked at their preferred speed while lower limb kinematic, kinetic and electromyography data were collected. FINDINGS: People with intermittent claudication walk slower and with reduced step length. Internal ankle plantarflexion moment (P = 0.004, effect size = 0.96) and ankle power generation (P < 0.001, effect size = 1.36) in late stance were significantly reduced for individuals with intermittent claudication. Significant moment and power reductions at the knee and power reduction at hip occurred in early stance, with similar reductions in early and late stance for ground reaction forces. Peak electromyography of soleus activity was significantly reduced in late stance (P = 0.01, effect size = 1.1, n = 13). Effects were independent of walking speed. INTERPRETATION: Reductions in ankle plantarflexion moments and power generation were consistent with reduced soleus electromyography activity and reduced peak vertical ground reaction forces during late stance. These effects are not due to a reduced walking speed. Changes in knee and hip function are also unrelated to walking speed. These outcomes provide a platform for the design and evaluation of interventions that seek to restore normal walking and improve pain-free walking distances for people with intermittent claudication.

The "price-tag" of foot health in infancy and early childhood: a cross sectional survey of UK parents.

Children's feet are complex structures and strategies for supporting good foot health throughout childhood can be challenging. Greater awareness of the contemporary factors influencing decisions, such as footwear purchases, is needed to inform health narratives which are more closely aligned to parents' attitude and behaviours. The aim of this study was to explore parent's knowledge of children's foot health, understand the common foot health concerns and experiences with footcare services. A purposeful sampling approach was used to recruit parents of children aged 5 years and under. Participants completed a self-administered, online survey which consisted of 39 questions across six sections: (1) Participant demographics; (2) Developmental events (milestones such as crawling and walking); (3) Foot health concerns; (4) Developmental aids (products such as baby bouncers and baby walkers); (5) Footwear; and (6) Foot health information. Both adaptive and mandatory questions were used. Descriptive statistics were used to summarise closed-ended questions, and a summative content analysis was adopted to draw inferences from the text data. Two-hundred thirty-nine parents completed the survey, and this represented female participants (n = 213) aged between the ages 34-42 (n = 126) or 25-34 (n = 83) years of age. The survey generated responses from a wide geographical spread across the UK, but the majority of these were from the North West of England (n = 75) and South East of England (n = 46). Four main themes were drawn from the content analysis: (1) foot health concerns and seeking advice; (2) information and advice; (3) how parents support infant milestone events; and (4) footwear.Conclusion: This work provides insight into parents' perspective on the broad topics of children's foot health, identifying common experiences and concerns about their children's foot health and the factors which influence decision making. Understanding more about these issues will help health professionals support parents during infancy and early years. What is Known: • Maintaining good foot health throughout childhood is important and many factors influence decision making. • There is little understanding about how parents care for their children feet and their understanding of good foot health practices and services. What is New: • Insight into the common factors which influence parents' approaches to supporting early development and the typical concerns that parents encountered about their children's overall foot health and footwear. • Identifies areas of children's foot health for health professionals to target when developing information sources for parents.

Comfortably numb? Experiences of people with stroke and lower limb sensation deficits: impact and solutions.

PURPOSE: To explore personal experiences of loss of foot sensation following stroke in order to inform the focus of clinical assessments and development of a vibrotactile insole. METHODS: Qualitative design with an interpretive phenomenological approach to data collection and analysis. Eight community dwelling adults with stroke (>6 months) and sensory impairment in the feet participated. Data was collected via conversational style interviews which were transcribed and analyzed using a thematic framework. Themes were verified with co-researchers and a lay advisory group. RESULTS: Data formed four themes: Sensory deficits are prevalent and constant, but individual and variable; Sensory deficits have a direct impact on balance, gait, mobility and falls; Sensory deficits have consequences for peoples' lives; Footwear is the link between function, the environment and identity. They embraced the concept of discrete vibrotactile insoles, their potential benefits and demonstrated a willingness to try it. CONCLUSIONS: Sensory deficit contributes to effects upon physical function, mobility and activity. Clinical outcome measures need to capture the emotional, psychological and social impacts of sensory deficit. Participants demonstrated a resilience and resourcefulness through adaption in daily living and self-management of footwear. The participants focus on footwear provides the opportunity to develop discrete and non-burdensome vibrotactile insoles for this patient group.IMPLICATIONS FOR REHABILITATIONSensory deficits are wide ranging and varied and are not distinct from motor deficits though contribute to the overall effect on physical function, mobility and activity.The physical effects impact on participants' lives emotionally, psychologically and socially. Measurement of outcomes need to capture specific activities that are valued by patients.The participants have revealed resilience and resourcefulness to create a "new normal" for their lives through adaption and self-management with a focus being on footwear as a solution.The participants have revealed the need for insole interventions to be discreet and non-burdensome, welcoming insole technology and contributing to the design and features of such insoles.

Development and evaluation of a dual density insole for people standing for long periods of time at work.

BACKGROUND: Appropriate footwear is important for those who stand for prolonged periods of time at work, enabling them to remain comfortable, healthy and safe. Preferences for different footwear cushioning or hardness are often person specific and one shoe or insole will not be the choice for all. The aim of this study was to develop a range of insole options to maintain comfort during long periods of standing at work and test insole material preferences in the workplace. METHODS: The study consisted of two parts. Part one evaluated 9 insoles of the same geometry that varied in hardness under 2 different plantar regions (n = 34). Insole preference, plantar pressure and selected anthropometric foot measures were taken. Three insole designs based on the most preferred options were identified from this part. In part two, these three insoles were evaluated with 22 workers immediately after trying them on (1 min) and after a working day. Foot anthropometric measures and subjective questions concerning material hardness preferences and self-reported foot characteristics were used to investigate whether either had a relationship with insole preference. RESULTS: Part one found insole preference predominantly varied according to material hardness under the medial arch rather than the heel/forefoot. Softer material under the heel and forefoot was associated with a reduction in peak pressures in these regions (p < 0.05). The most preferred insole had lower pressures under the hallux and first metatarsal phalangeal joint, and greater pressures and contact area under the medial midfoot (p < 0.05) compared to the least preferred insole. Height and foot anthropometrics were related to insole preference. In part two, under real world conditions, insole preference changed for 65% of participants between the immediate assessment (1 min) and after a whole workday, with dorsum height related to the latter (p < 0.05). Subjective questions for self-assessed arch height and footwear feel identified 66.7% of the insole preferences after 1 day at work, compared to 36% using immediate assessment of insole preference. CONCLUSION: Preference for material hardness varies underneath the medial arch of the foot and is time dependent. Simple foot measures and questions about comfort can guide selection of preferred insoles.

Steps towards evidence-based foot-care for children: Behaviour and opinions of health professionals.

Allied health professionals (AHPs) working with children need the appropriate knowledge, skills and experiences to provide high-quality care. This includes using research to drive improvements in care and ensuring that knowledge and practices are consistent and build upon the best available evidence. The aim of this work was to understand more about the shared behaviours and opinions of health professionals supporting children's foot health care; how they find information that is both relevant to their clinical practice as well as informing the advice they share. A qualitative design using semi-structured, one-to-one, telephone interviews with AHPs was adopted. Thematic analysis was used to generate meaning, identify patterns and develop themes from the data. Eight interviews were conducted with physiotherapists, podiatrists and orthotists. Five themes were identified relating to health professionals: (a) Engaging with research; (b) Power of experience; (c) Influence of children's footwear companies; (d). Dr Google - the new expert and (e) Referral pathways for children's foot care. The findings indicate that the AHPs adopted a number of strategies to develop and inform their own professional knowledge and clinical practice. There could be barriers to accessing information, particularly in areas where there is limited understanding or gaps in research. The availability of online foot health information was inconsistent and could impact on how AHPs were able to engage with parents during consultations.

Symptomatic pes planus in children: a synthesis of allied health professional practices.

BACKGROUND: This study sought to explore professional perspectives on the assessment and management of symptomatic pes planus in children. METHODS: Data was collected from three professional groups (podiatrists, physiotherapists, and orthotists) with experience of managing foot problems in children. The survey was undertaken in the United Kingdom via a self-administered, online survey. Data was captured over a four-month period in 2018. RESULTS: Fifty-five health professionals completed the survey and the results highlighted that assessment techniques varied between professions, with standing tip-toe and joint range of motion being the most common. Treatment options for children were diverse and professionals were adopting different strategies as their first line intervention. All professions used orthoses. CONCLUSIONS: There were inconsistencies in how the health professionals assessed children presenting with foot symptoms, variation in how the condition was managed and differences in outcome measurement. These findings might be explained by the lack of robust evidence and suggests that more effort is needed to harmonise assessment and treatment approaches between professions. Addressing discrepancies in practice could help prioritise professional roles in this area, and better support the management of children with foot pain.

Professional appraisal of online information about children's footwear measurement and fit: readability, usability and quality.

BACKGROUND: Parents increasingly use the internet to seek health information, share information and for purchasing textiles and footwear. This shift in footwear purchasing habits raises concern about how (and if) parents are getting their children's feet measured, and what support strategies are in place to support the fit of footwear. In response to this, some companies and healthcare organisations have developed resources to support home measurement of foot size, and link these measures to footwear selection, measurement and fitting. The aim of this research was to undertake an appraisal of web-based resources about measurement and fit of children's footwear, focussing specifically on readability, usability and quality. METHODS: Search terms relating to children's foot measurement were compiled and online searching was undertaken. Search results were saved and screened for relevance. Existing resources were categorised based on their source e.g. a footwear company or a health website. The 15 most commonly identified resources were reviewed by a professional panel for readability, content, usability and validity. One researcher also assessed the accessibility and reading ease of the resources. RESULTS: Online resources were predominantly from commercial footwear companies (54%). Health information sources from professional bodies made up 4.2% of the resources identified. The top 15 resources had appropriate reading ease scores for parents (SMOG Index 4.3-8.2). Accessibility scores (the product of the number of times it appeared in search results and its ranking in the results) were highest for commercial footwear companies. The panel scores for readability ranged from 2.7 to 9 out of 10, with a similar range for content, usability and validity. CONCLUSIONS: Information for parents seeking to purchase footwear for their children is readily available online but this was largely dominated by commercial footwear companies. The quality and usability of this information is of a moderate standard; notable improvements could be made to the validity of the task the child is asked to undertake and the measures being taken. Improvements in these resources would improve the data input to the selection of footwear and therefore have a beneficial impact on footwear fit in children.

International approaches to paediatric podiatry curricula: It's the same, but different.

INTRODUCTION: Pre-registration / entry-level programmes of study provide the core knowledge, skills and abilities required for clinical practice. These programmes are where students are introduced to specialist domains of practice and begin to shape their professional interests. The aim of this research was to describe paediatric curricula within pre-registration and entry level podiatry programmes across comparable universities and offer a contemporary synthesis of international practices. METHODS: An exploratory, cross-sectional, online survey was undertaken across a three-month period. Representatives from podiatry programmes delivering pre-registration or entry level podiatry degrees in which graduates are eligible for Professional and Statutory Body registration within their country (deemed at a Bachelor degree or higher), were invited to participate. The survey was administered online using Online Surveys. Descriptive statistics were used to describe the data due to the exploratory nature of the research question and design. RESULTS: There were responses from seven (54% of 13) universities in the United Kingdom (UK), nine (100% of nine) universities in Australia and four (50% of eight) of the invited universities external to the UK and Australia (New Zealand, Malta, Ireland, South Africa). There was some variation in curriculum content, but all universities reported to cover ontogeny and developmental milestones and general paediatric orthopaedic conditions. There was further discrepancy with the number of hours dedicated to paediatric podiatry within the curricula (ranging from < 5 h to > 26 h). CONCLUSION: The findings from this study highlight some disparity in the delivery of training for students relating to paediatrics. The data suggests that there is a need for international coordination in establishing priorities for the paediatric curricula. This will ensure consistency in baseline knowledge, modes of training, amount and nature of curriculum delivery during undergraduate or entry level podiatry training.

Big issues for small feet: developmental, biomechanical and clinical narratives on children's footwear.

The effects of footwear on the development of children's feet has been debated for many years and recent work from the developmental and biomechanical literature has challenged long-held views about footwear and the impact on foot development. This narrative review draws upon existing studies from developmental, biomechanical and clinical literature to explore the effects of footwear on the development of the foot. The emerging findings from this support the need for progress in [children's] footwear science and advance understanding of the interaction between the foot and shoe. Ensuring clear and credible messages inform practice requires a progressive evidence base but this remains big issue in children's footwear research.

Subject-specific finite element modelling of the human foot complex during walking: sensitivity analysis of material properties, boundary and loading conditions.

The objective of this study was to develop and validate a subject-specific framework for modelling the human foot. This was achieved by integrating medical image-based finite element modelling, individualised multi-body musculoskeletal modelling and 3D gait measurements. A 3D ankle-foot finite element model comprising all major foot structures was constructed based on MRI of one individual. A multi-body musculoskeletal model and 3D gait measurements for the same subject were used to define loading and boundary conditions. Sensitivity analyses were used to investigate the effects of key modelling parameters on model predictions. Prediction errors of average and peak plantar pressures were below 10% in all ten plantar regions at five key gait events with only one exception (lateral heel, in early stance, error of 14.44%). The sensitivity analyses results suggest that predictions of peak plantar pressures are moderately sensitive to material properties, ground reaction forces and muscle forces, and significantly sensitive to foot orientation. The maximum region-specific percentage change ratios (peak stress percentage change over parameter percentage change) were 1.935-2.258 for ground reaction forces, 1.528-2.727 for plantar flexor muscles and 4.84-11.37 for foot orientations. This strongly suggests that loading and boundary conditions need to be very carefully defined based on personalised measurement data.

Time to revise our dialogue: how flat is the paediatric flatfoot?

A recent systematic review of measures of foot development used the medial longitudinal arch profile as its primary indicator of development. A comparative analysis of existing studies was undertaken. This work confirmed changes with arch profile were age-dependent, although the age at which foot development ceased remains unknown. This work also highlighted the abundance of clinical measures used in existing research and outlined the challenges with drawing consensus from available data. There is a clear need to move this debate forward and, to do so, it is essential that scientific and clinical communities unite. It is time to abandon ill-defined measures of foot position, look beyond the medial longitudinal arch as a sole parameter of foot development and re-focus our perspective(s) on the paediatric foot in order to make advances with clinical practice and research.

The effect of intracortical bone pin application on kinetics and tibiocalcaneal kinematics of walking gait.

Bone anchored markers using intracortical bone pins are one of the few available methods for analyzing skeletal motion during human gait in-vivo without errors induced by soft tissue artifacts. However, bone anchored markers require local anesthesia and may alter the motor control and motor output during gait. The purpose of this study was to examine the effect of local anesthesia and the use of bone anchored markers on typical gait analysis variables. Five subjects were analyzed in two different gait analysis sessions. In the first session, a protocol with skin markers was used. In the second session, bone anchored markers were added after local anesthesia was applied. For both sessions, three dimensional infrared kinematics of the calcaneus and tibia segments, ground reaction forces, and plantar pressure data were collected. 95% confidence intervals and boxplots were used to compare protocols and assess the data distribution and data variability for each subject. Although considerable variation was found between subjects, within-subject comparison of the two protocols revealed non-systematic effects on the target variables. Two of the five subjects walked at reduced gait speed during the bone pin session, which explained the between-session differences found in kinetic and kinematic variables. The remaining three subjects did not systematically alter their gait pattern between the two sessions. Results support the hypothesis that local anesthesia and the presence of bone pins still allow a valid gait pattern to be analyzed.

Early observations of the effects of lateral wedge orthoses on lower limb muscle length and potential for exacerbating spasticity.

Lateral wedge orthoses are often prescribed to correct varus deformity after stroke. Spasticity is implicated in varus deformity and is caused by velocity-related muscle length changes, so a lateral wedge may affect spasticity by manipulating foot and ankle kinematics which, in turn, may alter the length of these muscles. We sought to test this theory in healthy participants. Eight volunteers walked with no wedge and with lateral wedges of 5 and 8.5 degrees in both shoes. Qualysis motion capture system collected kinematic data and SIMM musculoskeletal modeling software calculated muscle tendon length of plantarflexor and peroneal muscle groups using 3-D ankle and knee joint angle data. The wedges increased ankle eversion (p < 0.0001) and total excursion of tibialis posterior, peroneus longus and brevis by 13-29% (p < 0.05). Muscle length of peroneus longus and brevis increased by <1% (p < 0.005). Potentially clinical meaningful effects were found for tibialis posterior (15%), peroneus brevis (23%) and peroneus tertius (13%). Further research is required to be conclusive and to explore the effects of lateral wedge orthoses in patients with stroke. If such changes are seen in people with stroke, a change in orthotic prescription practice could be indicated as lateral wedge orthoses may exacerbate spasticity.

A generic analytical foot rollover model for predicting translational ankle kinematics in gait simulation studies.

The objective of this paper is to develop an analytical framework to representing the ankle-foot kinematics by modelling the foot as a rollover rocker, which cannot only be used as a generic tool for general gait simulation but also allows for case-specific modelling if required. Previously, the rollover models used in gait simulation have often been based on specific functions that have usually been of a simple form. In contrast, the analytical model described here is in a general form that the effective foot rollover shape can be represented by any polar function rho=rho(phi). Furthermore, a normalized generic foot rollover model has been established based on a normative foot rollover shape dataset of 12 normal healthy subjects. To evaluate model accuracy, the predicted ankle motions and the centre of pressure (CoP) were compared with measurement data for both subject-specific and general cases. The results demonstrated that the ankle joint motions in both vertical and horizontal directions (relative RMSE approximately 10%) and CoP (relative RMSE approximately 15% for most of the subjects) are accurately predicted over most of the stance phase (from 10% to 90% of stance). However, we found that the foot cannot be very accurately represented by a rollover model just after heel strike (HS) and just before toe off (TO), probably due to shear deformation of foot plantar tissues (ankle motion can occur without any foot rotation). The proposed foot rollover model can be used in both inverse and forward dynamics gait simulation studies and may also find applications in rehabilitation engineering.