The Glasgow-Maastricht foot model, evaluation of a 26 segment kinematic model of the foot

BACKGROUND: Accurately measuring of intrinsic foot kinematics using skin mounted markers is difficult, limited in part by the physical dimensions of the foot. Existing kinematic foot models solve this problem by combining multiple bones into idealized rigid segments. This study presents a novel foot model that allows the motion of the 26 bones to be individually estimated via a combination of partial joint constraints and coupling the motion of separate joints using kinematic rhythms. METHODS: Segmented CT data from one healthy subject was used to create a template Glasgow-Maastricht foot model (GM-model). Following this, the template was scaled to produce subject-specific models for five additional healthy participants using a surface scan of the foot and ankle. Forty-three skin mounted markers, mainly positioned around the foot and ankle, were used to capture the stance phase of the right foot of the six healthy participants during walking. The GM-model was then applied to calculate the intrinsic foot kinematics. RESULTS: Distinct motion patterns where found for all joints. The variability in outcome depended on the location of the joint, with reasonable results for sagittal plane motions and poor results for transverse plane motions. CONCLUSIONS: The results of the GM-model were comparable with existing literature, including bone pin studies, with respect to the range of motion, motion pattern and timing of the motion in the studied joints. This novel model is the most complete kinematic model to date. Further evaluation of the model is warranted

What has finite element analysis taught us about diabetic foot disease and its management?:a systematic review

Over the past two decades finite element (FE) analysis has become a popular tool for researchers seeking to simulate the biomechanics of the healthy and diabetic foot. The primary aims of these simulations have been to improve our understanding of the foot's complicated mechanical loading in health and disease and to inform interventions designed to prevent plantar ulceration, a major complication of diabetes. This article provides a systematic review and summary of the findings from FE analysis-based computational simulations of the diabetic foot.A systematic literature search was carried out and 31 relevant articles were identified covering three primary themes: methodological aspects relevant to modelling the diabetic foot; investigations of the pathomechanics of the diabetic foot; and simulation-based design of interventions to reduce ulceration risk.Methodological studies illustrated appropriate use of FE analysis for simulation of foot mechanics, incorporating nonlinear tissue mechanics, contact and rigid body movements. FE studies of pathomechanics have provided estimates of internal soft tissue stresses, and suggest that such stresses may often be considerably larger than those measured at the plantar surface and are proportionally greater in the diabetic foot compared to controls. FE analysis allowed evaluation of insole performance and development of new insole designs, footwear and corrective surgery to effectively provide intervention strategies. The technique also presents the opportunity to simulate the effect of changes associated with the diabetic foot on non-mechanical factors such as blood supply to local tissues.While significant advancement in diabetic foot research has been made possible by the use of FE analysis, translational utility of this powerful tool for routine clinical care at the patient level requires adoption of cost-effective (both in terms of labour and computation) and reliable approaches with clear clinical validity for decision making

Generation of subject-specific, dynamic, multisegment ankle and foot models to improve orthotic design: a feasibility study

ABSTRACT: BACKGROUND: Currently, custom foot and ankle orthosis prescription and design tend to be based on traditional techniques, which can result in devices which vary greatly between clinicians and repeat prescription. The use of computational models of the foot may give further insight in the biomechanical effects of these devices and allow a more standardised approach to be taken to their design, however due to the complexity of the foot the models must be highly detailed and dynamic. METHODS: Functional and anatomical datasets will be collected in a multicentre study from 10 healthy participants and 15 patients requiring orthotic devices. The patient group will include individuals with metarsalgia, flexible flat foot and drop foot. Each participant will undergo a clinical foot function assessment, 3D surface scans of the foot under different loading conditions, and detailed gait analysis including kinematic, kinetic, muscle activity and plantar pressure measurements in both barefoot and shod conditions. Following this each participant will undergo computed tomography (CT) imaging of their foot and ankle under a range of loads and positions while plantar pressures are recorded. A further subgroup of participants will undergo magnetic resonance imaging (MRI) of the foot and ankle. Imaging data will be segmented to derive the size of bones and orientation of the joint axes. Insertion points of muscles and ligaments will be determined from the MRI and CT-scans and soft tissue material properties computed from the loaded CT data in combination with the plantar pressure measurements. Gait analysis data will be used to drive the models and in combination with the 3D surface scans for scaling purposes. Predicted plantar pressures and muscle activation patterns predicted from the models will be compared to determine the validity of the models. DISCUSSION: This protocol will lead to the generation of unique datasets which will be used to develop linked inverse dynamic and forward dynamic biomechanical foot models. These models may be beneficial in predicting the effect of and thus improving the efficacy of orthotic devices for the foot and ankle

The Glasgow-Maastricht foot model: development, repeatability and sources of error of a 26 segment multi-body foot model

This thesis describes the development of the Glasgow-Maastricht foot model, which allows the measurement of the movement of each individual foot and ankle bone. For example, the model allows the future measurement of the compensation required in the movement of joints after fixation of other foot joints. In addition to describing the development of the model, the thesis discusses the first steps towards validation and sources of model errors. The model shows similar results to previously conducted highly invasive research and is reproducible if the same researcher uses the model twice on the same person, and the error arising from skin movement is quantified

Veilig oversteken : inspiratiegids voor van-werk-naar werktransities : 10 paktijkvoorbeelden

De arbeidsmarkt vraagt er steeds vaker om dat werknemers van beroep veranderen of in een heel andere sector gaan werken. Zo doen zich momenteel tekorten voor in technische beroepen, maar zijn er tegelijkertijd enige honderdduizenden langdurig werklozen. Opleidingen sluiten lang niet altijd goed aan op wat de arbeidsmarkt vraagt, en de verwachting is dat de arbeidsmarkt steeds sneller verandert. In de Inspiratiegids Veilig oversteken zijn voorbeelden opgenomen van een aantal initiatieven om beter om te gaan met de veranderende arbeidsmarkt. Sleutelbegrip daarin is ‘van-werk-naar-werk’: zorgen dat werknemers die bij het ene bedrijf buiten de boot vallen snel en veilig door kunnen naar een heel andere baan bij een ander bedrijf, mogelijk ook in een andere sector, en werkloosheid zoveel mogelijk wordt voorkomen

The development of an innovative rehabilitation measurement system

Purpose: The aim of the work was to develop a rehabilitation analysis solution that was robust, simple to use, wireless and inexpensive that could facilitate research and application in areas that were previously impractical. Methods: The embodiment of this vision was a pressure measurement insole and optical knee angle sensor system capable of wirelessly logging data. A participant was equipped with an experimental version of the system and performed various gaits along a motion-lab runway. A Vicon system tracked the participant's motion along the runway and an embedded force plate measured contact forces. The motion-lab reference data was used to validate the system and identify correlations that could aid with data interpretation and possible applications of the system. Results: Validation of the insole device showed good correlation with reference data (r>0.9) for centre of pressure location and an accuracy of +/-0.2 ms for all timing parameters. The joint angle sensor demonstrated an accuracy of within +/-3 degrees. Further correlations in the data were identified enabling classification of gait patterns. Conclusion: The system proved to be reliable, robust and accurate enough to be used in a variety of "in the field" research and rehabilitation quantification product scenarios previously rendered impractical by existing technology products. © 2010 The authors and IOS Press. All rights reserved