Effect of rocker shoe design features on forefoot plantar pressures in people with and without diabetes

BACKGROUND

There is no consensus on the precise rocker shoe outsole design that will optimally reduce plantar pressure in people with diabetes. This study aimed to understand how peak plantar pressure is influenced by systematically varying three design features which characterise a curved rocker shoe: apex angle, apex position and rocker angle.

METHODS

A total of 12 different rocker shoe designs, spanning a range of each of the three design features, were tested in 24 people with diabetes and 24 healthy participants. Each subject also wore a flexible control shoe. Peak plantar pressure, in four anatomical regions, was recorded for each of the 13 shoes during walking at a controlled speed.

FINDINGS

There were a number of significant main effects for each of the three design features, however, the precise effect of each feature varied between the different regions. The results demonstrated maximum pressure reduction in the 2nd-4th metatarsal regions (39%) but that lower rocker angles (<20°) and anterior apex positions (>60% shoe length) should be avoided for this region. The effect of apex angle was most pronounced in the 1st metatarsophalangeal region with a clear decrease in pressure as the apex angle was increased to 100°.

INTERPRETATION

We suggest that an outsole design with a 95° apex angle, apex position at 60% of shoe length and 20° rocker angle may achieve an optimal balance for offloading different regions of the forefoot. However, future studies incorporating additional design feature combinations, on high risk patients, are required to make definitive recommendations.

A systematic review and meta-analysis of the effect of an ankle-foot orthosis on gait biomechanics after stroke

OBJECTIVE

To systematically review the evidence on the effects of an ankle-foot orthosis on gait biomechanics after stroke.

DATA SOURCES

The following databases were searched; AMED, CINHAL, Cochrane Library (Stroke section), Medline, PubMed, Science Direct and Scopus. Previous reviews, reference lists and citation tracking of the selected articles were screened and the authors of selected trials contacted for any further unpublished data.

REVIEW METHODS

Controlled trials of an ankle-foot orthosis on gait biomechanics in stroke survivors were identified. A modified PEDro score evaluated trial quality; those scoring 4/8 or more were selected. Information on the trial design, population, intervention, outcomes, and mean and standard deviation values for the treatment and control groups were extracted. Continuous outcomes were pooled according to their mean difference and 95% confidence intervals in a fixed-effect model.

RESULTS

Twenty trials involving 314 participants were selected. An ankle-foot orthosis had a positive effect on ankle kinematics (P < 0.00001-0.0002); knee kinematics in stance phase (P < 0.0001-0.01); kinetics (P = 0.0001) and energy cost (P = 0.004), but not on knee kinematics in swing phase (P = 0.84), hip kinematics (P < 0.18-0.89) or energy expenditure (P = 0.43). There were insufficient data for pooled analysis of individual joint moments, muscle activity or spasticity. All trials, except one, evaluated immediate effects only.

CONCLUSIONS

An ankle-foot orthosis can improve the ankle and knee kinematics, kinetics and energy cost of walking in stroke survivors.

Foot orthoses for the management of low back pain: a qualitative approach capturing the patient's perspective

BACKGROUND

The onset of non specific low back pain is associated with heavy lifting, age, female gender, and poor general health, with psychological factors being predictors of it becoming chronic. Additionally, it is thought that altered lower limb biomechanics are a contributory factor, with foot orthoses increasingly being considered as an appropriate intervention by physiotherapists and podiatrists. However, research into the effect of foot orthoses is inconclusive, primarily focusing on the biomechanical effect and not the symptomatic relief from the patient's perspective. The aim of this study was to explore the breadth of patients' experiences of being provided with foot orthoses and to evaluate any changes in their back pain following this experience.

METHOD

Following ethical approval, participants (n = 25) with non-specific low back pain associated with altered lower limb biomechanics were provided with customised foot orthoses. At 16 weeks after being provided with the foot orthoses, conversational style interviews were carried out with each patient. An interpretivistic phenomenological approach was adopted for the data collection and analysis.

RESULTS

For these participants, foot orthoses appeared to be effective. However, the main influence on this outcome was the consultation process and a patient focussed approach. The consultation was an opportunity for fostering mutual understanding, with verbal and visual explanation reassuring the patient and this influenced the patient's beliefs, their engagement with the foot orthoses (physical) and their experience of low back pain (psychological).

CONCLUSION

Clinicians need to adopt 'psychologically informed practice' in relation to the provision of foot orthoses. Likewise, researchers should consider all the influencing factors found in this study, both in relation to their study protocol and the outcomes they plan to measure.

Reliability of ultrasound to measure morphology of the toe flexor muscles

Background

Measuring the strength of individual foot muscles is very challenging; however, measuring muscle morphology has been shown to be associated with strength. A reliable method of assessing foot muscle atrophy and hypertrophy would therefore be beneficial to researchers and clinicians. Thus, the aim of this study was to evaluate the test-retest intra-observer reliability of ultrasound to measure the morphology of the primary toe flexor muscles.

Method

The abductor hallucis, flexor hallucis brevis, flexor digitorum brevis, quadratus plantae and abductor digiti minimi muscles in the foot, and the flexor digitorum longus and flexor hallucis longus muscles in the shank were assessed in five males and five females (mean age = 32.1 ± 10.1 years). Muscles were imaged using a GE Venue 40 ultrasound (6-9 or 7.6-10.7 MHz transducer) in a random order, and on two occasions 1-6 days apart. Muscle thickness and cross-sectional area were measured using Image J software with the assessor blinded to muscle and day of scan. Intraclass correlation coefficients (ICC) and limits of agreement were calculated to assess day-to-day repeatability of the measurements.

Results

The method was found to have good reliability (ICC = 0.89-0.99) with limits of agreement between 8-28% of the relative muscle size.

Conclusion

The protocol described in this paper showed that ultrasound is a reliable method to measure morphology of the toe flexor muscles. The portability and advantages of ultrasound make it a useful tool for clinical and research settings.

The effects of transcutaneous electrical nerve stimulation on strength, proprioception, balance and mobility in people with stroke: a randomized controlled cross-over trial

OBJECTIVE

To investigate the feasibility and potential efficacy of 'activeTENS' (that is transcutaneous electrical nerve stimulation (TENS) during everyday activities) by assessing the immediate effects on strength, proprioception, balance/falls risk and mobility after stroke.

DESIGN

A paired-sample randomized cross-over trial.

SUBJECTS

Twenty-nine mobile chronic stroke survivors with no pre-existing conditions limiting balance or mobility or contra-indications to TENS.

SETTING

University clinical research facility.

INTERVENTION

A single session of 'activeTENS' delivered via a 'sock electrode' (70-130 Hz, five second cycle) plus a session of control treatment (wearing the sock electrode with no stimulation), lasting approximately two hours in total.

MAIN OUTCOMES

Dorsiflexor and plantarflexor strength and proprioception using an isokinetic dyanometer, balance and falls risk (Standing Forward Reach Test) and gait speed (10-m walk test).

RESULTS

All participants tolerated 'active TENS'. Most parameters improved during stimulation with activeTENS; balance (p = 0.009), gait speed (p = 0.002), plantarflexor strength (p = 0.008) and proprioception of plantarflexion (p = 0.029), except dorsiflexor strength (p = 0.194) and dorsiflexion proprioception (p = 0.078).

CONCLUSIONS

The results provide initial evidence of the potential of 'active TENS' to benefit physical function after stroke which warrants further phase II trials to develop the intervention. Concerns that stimulation could have a detrimental impact on balance and increase risk of falls were not supported.

A comparison of the biomechanical effects of valgus knee braces and lateral wedged insoles in patients with knee osteoarthritis

Increases in the external knee adduction moment (EKAM) have been associated with increased mechanical load at the knee and progression of knee osteoarthritis. Valgus knee braces and lateral wedged insoles are common approaches to reducing this loading; however no study has directly compared the biomechanical and clinical effects of these two treatments in patients with medial tibiofemoral osteoarthritis. A cross-over randomised design was used where each intervention was worn by 28 patients for a two week period. Pre- and post-intervention gait kinematic/kinetic data and clinical outcomes were collected to evaluate the biomechanical and clinical effects on the knee joint. The valgus knee brace and the lateral wedged insole significantly increased walking speed, reduced the early stance EKAM by 7% and 12%, and the knee adduction angular impulse by 8.6 and 16.1% respectively. The lateral wedged insole significantly reduced the early stance EKAM compared to the valgus knee brace (p=0.001). The valgus knee brace significantly reduced the knee varus angle compared to the baseline and lateral wedged insole. Improvements in pain and function subscales were comparable for the valgus knee brace and lateral wedged insole. There were no significant differences between the two treatments in any of the clinical outcomes; however the lateral wedged insoles demonstrated greater levels of acceptance by patients. This is the first study to biomechanically compare these two treatments, and demonstrates that given the potential role of knee loading in osteoarthritis progression, that both treatments reduce this but lateral wedge insoles appear to have a greater effect.

Inter-assessor reliability of practice based biomechanical assessment of the foot and ankle

Background

There is no consensus on which protocols should be used to assess foot and lower limb biomechanics in clinical practice. The reliability of many assessments has been questioned by previous research. The aim of this investigation was to (i) identify (through consensus) what biomechanical examinations are used in clinical practice and (ii) evaluate the inter-assessor reliability of some of these examinations.

Methods

Part1: Using a modified Delphi technique 12 podiatrists derived consensus on the biomechanical examinations used in clinical practice. Part 2: Eleven podiatrists assessed 6 participants using a subset of the assessment protocol derived in Part 1. Examinations were compared between assessors.

Results

Clinicians choose to estimate rather than quantitatively measure foot position and motion. Poor inter-assessor reliability was recorded for all examinations. Intra-class correlation coefficient values (ICC) for relaxed calcaneal stance position were less than 0.23 and were less than 0.14 for neutral calcaneal stance position. For the examination of ankle joint dorsiflexion, ICC values suggest moderate reliability (less than 0.61). The results of a random effects ANOVA highlight that participant (up to 5.7°), assessor (up to 5.8°) and random (up to 5.7°) error all contribute to the total error (up to 9.5° for relaxed calcaneal stance position, up to 10.7° for the examination of ankle joint dorsiflexion). Kappa Fleiss values for categorisation of first ray position and mobility were less than 0.05 and for limb length assessment less than 0.02, indicating slight agreement.

Conclusion

Static biomechanical assessment of the foot, leg and lower limb is an important protocol in clinical practice, but the key examinations used to make inferences about dynamic foot function and to determine orthotic prescription are unreliable.

Foot kinematics in patients with two patterns of pathological plantar hyperkeratosis

Background

The Root paradigm of foot function continues to underpin the majority of clinical foot biomechanics practice and foot orthotic therapy. There are great number of assumptions in this popular paradigm, most of which have not been thoroughly tested. One component supposes that patterns of plantar pressure and associated hyperkeratosis lesions should be associated with distinct rearfoot, mid foot, first metatarsal and hallux kinematic patterns. Our aim was to investigate the extent to which this was true.

Methods

Twenty-seven subjects with planter pathological hyperkeratosis were recruited into one of two groups. Group 1 displayed pathological plantar hyperkeratosis only under metatarsal heads 2, 3 and 4 (n = 14). Group 2 displayed pathological plantar hyperkeratosis only under the 1^st and 5^th metatarsal heads (n = 13). Foot kinematics were measured using reflective markers on the leg, heel, midfoot, first metatarsal and hallux.

Results

The kinematic data failed to identify distinct differences between these two groups of subjects, however there were several subtle (generally <3°) differences in kinematic data between these groups. Group 1 displayed a less everted heel, a less abducted heel and a more plantarflexed heel compared to group 2, which is contrary to the Root paradigm.

Conclusions

There was some evidence of small differences between planter pathological hyperkeratosis groups. Nevertheless, there was too much similarity between the kinematic data displayed in each group to classify them as distinct foot types as the current clinical paradigm proposes.

Women's experiences of wearing therapeutic footwear in three European countries

BACKGROUND

Therapeutic footwear is recommended for those people with severe foot problems associated with rheumatoid arthritis (RA). However, it is known that many do not wear them. Although previous European studies have recommended service and footwear design improvements, it is not known if services have improved or if this footwear meets the personal needs of people with RA. As an earlier study found that this footwear has more impact on women than males, this study explores women's experiences of the process of being provided with it and wearing it. No previous work has compared women's experiences of this footwear in different countries, therefore this study aimed to explore the potential differences between the UK, the Netherlands and Spain.

METHOD

Women with RA and experience of wearing therapeutic footwear were purposively recruited. Ten women with RA were interviewed in each of the three countries. An interpretive phenomenological approach (IPA) was adopted during data collection and analysis. Conversational style interviews were used to collect the data.

RESULTS

Six themes were identified: feet being visibly different because of RA; the referring practitioners' approach to the patient; the dispensing practitioners' approach to the patient; the footwear being visible as different to others; footwear influencing social participation; and the women's wishes for improved footwear services. Despite their nationality, these women revealed that therapeutic footwear invokes emotions of sadness, shame and anger and that it is often the final and symbolic marker of the effects of RA on self perception and their changed lives. This results in severe restriction of important activities, particularly those involving social participation. However, where a patient focussed approach was used, particularly by the practitioners in Spain and the Netherlands, the acceptance of this footwear was much more evident and there was less wastage as a result of the footwear being prescribed and then not worn. In the UK, the women were more likely to passively accept the footwear with the only choice being to reject it once it had been provided. All the women were vocal about what would improve their experiences and this centred on the consultation with both the referring practitioner and the practitioner that provides the footwear.

CONCLUSION

This unique study, carried out in three countries has revealed emotive and personal accounts of what it is like to have an item of clothing replaced with an 'intervention'. The participant's experience of their consultations with practitioners has revealed the tension between the practitioners' requirements and the women's 'social' needs. Practitioners need greater understanding of the social and emotional consequences of using therapeutic footwear as an intervention.

International Foot and Ankle Biomechanics Community (i-FAB): past, present and beyond

The International Foot and Ankle Biomechanics Community (i-FAB) is an international collaborative activity which will have an important impact on the foot and ankle biomechanics community. It was launched on July 2^nd 2007 at the foot and ankle session of the International Society of Biomechanics (ISB) meeting in Taipei, Taiwan. i-FAB is driven by the desire to improve our understanding of foot and ankle biomechanics as it applies to health, disease, and the design, development and evaluation of foot and ankle surgery, and interventions such as footwear, insoles and surfaces.

Lessons from dynamic cadaver and invasive bone pin studies: do we know how the foot really moves during gait?

BACKGROUND

This paper provides a summary of a Keynote lecture delivered at the 2009 Australasian Podiatry Conference. The aim of the paper is to review recent research that has adopted dynamic cadaver and invasive kinematics research approaches to better understand foot and ankle kinematics during gait. It is not intended to systematically cover all literature related to foot and ankle kinematics (such as research using surface mounted markers). Since the paper is based on a keynote presentation its focuses on the authors own experiences and work in the main, drawing on the work of others where appropriate

METHODS

Two approaches to the problem of accessing and measuring the kinematics of individual anatomical structures in the foot have been taken, (i) static and dynamic cadaver models, and (ii) invasive in-vivo research. Cadaver models offer the advantage that there is complete access to all the tissues of the foot, but the cadaver must be manipulated and loaded in a manner which replicates how the foot would have performed when in-vivo. The key value of invasive in-vivo foot kinematics research is the validity of the description of foot kinematics, but the key difficulty is how generalisable this data is to the wider population.

RESULTS

Through these techniques a great deal has been learnt. We better understand the valuable contribution mid and forefoot joints make to foot biomechanics, and how the ankle and subtalar joints can have almost comparable roles. Variation between people in foot kinematics is high and normal. This includes variation in how specific joints move and how combinations of joints move. The foot continues to demonstrate its flexibility in enabling us to get from A to B via a large number of different kinematic solutions.

CONCLUSION

Rather than continue to apply a poorly founded model of foot type whose basis is to make all feet meet criteria for the mechanical 'ideal' or 'normal' foot, we should embrace variation between feet and identify it as an opportunity to develop patient-specific clinical models of foot function.

Rheumatoid arthritis patients' experiences of wearing therapeutic footwear - a qualitative investigation

BACKGROUND

Specialist 'therapeutic' footwear is recommended for patients with diseases such as rheumatoid arthritis (RA) as a beneficial intervention for reducing foot pain, improving foot health, and increasing general mobility. However, many patients choose not to wear this footwear. Recommendations from previous studies have been implemented but have had little impact in improving this situation. The aim of this study was to explore RA patients' experiences of this footwear to ascertain the factors which influence their choice to wear it or not.

METHOD

Ten females and three males with RA and experience of wearing specialist footwear were recruited from four National Health Service orthotic services. Semi-structured interviews were carried out in the participants own homes. A hermeneutic phenomenological analysis of the transcripts was carried out to identify themes.

RESULTS

The analysis revealed two main themes from both the female and male groups. These were the participants' feelings about their footwear and their experiences of the practitioner/s involved in providing the footwear. In addition, further themes were revealed from the female participants. These were feelings about their feet, behaviour associated with the footwear, and their feelings about what would have improved their experience.

CONCLUSION

Unlike any other intervention specialist therapeutic footwear replaces something that is normally worn and is part of an individual's body image. It has much more of a negative impact on the female patients' emotions and activities than previously acknowledged and this influences their behaviour with it. The patients' consultations with the referring and dispensing practitioners are pivotal moments within the patient/practitioner relationship that have the potential to influence whether patients choose to wear the footwear or not.

The Development and Validity of the Salford Gait Tool: An Observation-Based Clinical Gait Assessment Tool

OBJECTIVES

To develop the construct, content, and criterion validity of the Salford Gait Tool (SF-GT) and to evaluate agreement between gait observations using the SF-GT and kinematic gait data.

DESIGN

Tool development and comparative evaluation.

SETTING

University in the United Kingdom.

PARTICIPANTS

For designing construct and content validity, convenience samples of 10 children with hemiplegic, diplegic, and quadriplegic cerebral palsy (CP) and 152 physical therapy students and 4 physical therapists were recruited. For developing criterion validity, kinematic gait data of 13 gait clusters containing 56 children with hemiplegic, diplegic, and quadriplegic CP and 11 neurologically intact children was used. For clinical evaluation, a convenience sample of 23 pediatric physical therapists participated.

INTERVENTIONS

We developed a sagittal plane observational gait assessment tool through a series of design, test, and redesign iterations. The tool's grading system was calibrated using kinematic gait data of 13 gait clusters and was evaluated by comparing the agreement of gait observations using the SF-GT with kinematic gait data.

MAIN OUTCOME MEASURES

Criterion standard kinematic gait data.

RESULTS

There was 58% mean agreement based on grading categories and 80% mean agreement based on degree estimations evaluated with the least significant difference method.

CONCLUSIONS

The new SF-GT has good concurrent criterion validity.

Inter- and Intraobserver Repeatability of the Salford Gait Tool: An Observation-Based Clinical Gait Assessment Tool

OBJECTIVE

To evaluate the inter- and intraobserver repeatability of the Salford Gait Tool (SF-GT), a new observation-based gait assessment tool for evaluating sagittal plane cerebral palsy (CP) gait.

DESIGN

Masked comparative evaluation.

SETTING

University in the United Kingdom.

PARTICIPANTS

A convenience sample of 23 pediatric physical therapists with varying degrees of clinical experience recruited from the Greater Manchester area.

INTERVENTION

Participants viewed videotapes of the sagittal plane gait of 13 children and used the SF-GT to analyze their 13 different gait styles on 2 occasions. Eleven children had hemiplegic, diplegic, or quadriplegic CP and 2 were neurologically intact.

MAIN OUTCOME MEASURES

Inter- and intraobserver repeatability of hip, knee, and ankle joint positions at 6 different phases of the gait cycle.

RESULTS

The SF-GT demonstrated good interobserver (77%) and intraobserver (75%) repeatability.

CONCLUSIONS

We have established that the SF-GT is a repeatable clinical assessment tool with which to guide the diagnosis, treatment planning, and evaluation of interventions by pediatric physical therapists of sagittal plane gait deviations in CP.

Cluster analysis for the extraction of sagittal gait patterns in children with cerebral palsy

Classification of gait disorders would facilitate standardisation of gait management and communication across professional boundaries. In the past, such classification was undertaken using a variety of approaches with often unclear methodology and validation procedures. This study describes the application of hierarchical cluster analysis on sagittal kinematic gait data derived from 56 children with cerebral palsy and 11 neurologically intact children in order to define existing clusters of gait patterns in the children's data. A structured rationale was developed to seek and validate the optimal number of homogenous gait types within the data resulting in 13 different gait clusters that were organised into 'crouch gait type', 'equinus gait type' and 'other gait type'. Applying cluster analysis in combination with visual assessment of gait data and a structured protocol, we have been able to define valid gait groupings.

In vitro study of foot kinematics using a dynamic walking cadaver model

There is a dearth of information on navicular, cuboid, cuneiform and metatarsal kinematics during walking and our objective was to study the kinematic contributions these bones might make to foot function. A dynamic cadaver model of walking was used to apply forces to cadaver feet and mobilise them in a manner similar to in vivo. Kinematic data were recorded from 13 cadaver feet. Given limitations to the simulation, the data describe what the cadaver feet were capable of in response to the forces applied, rather than exactly how they performed in vivo. The talonavicular joint was more mobile than the calcaneocuboid joint. The range of motion between cuneiforms and navicular was similar to that between talus and navicular. Metatarsals four and five were more mobile relative to the cuboid than metatarsals one, two and three relative to the cuneiforms. This work has confirmed the complexity of rear, mid and forefoot kinematics. The data demonstrate the potential for often-ignored foot joints to contribute significantly to the overall kinematic function of the foot. Previous emphasis on the ankle and sub talar joints as the principal articulating components of the foot has neglected more distal articulations. The results also demonstrate the extent to which the rigid segment assumptions of previous foot kinematics research have over simplified the foot.

Foot pathology in patients with Paget's disease of bone

The characteristic bone deformities associated with advanced Paget's disease of bone may result in abnormal gait and plantar foot pressures, which contribute to the development of pressure-related skin problems. This study aimed to characterize the foot problems and foot-care needs in this patient group and to investigate the effect of disease distribution on the occurrence of foot pathology. One hundred thirty-four patients with Paget's disease were assessed clinically, and the Foot Structure Index was completed for each patient. Patients completed self-administered questionnaires concerning foot function (Foot Function Index) and quality of life (12-Item Short Form). The results of this study suggest that foot-health and footwear problems are common in patients with Paget's disease. Forty percent of the patients required professional foot care in addition to those already receiving it. The site of pagetic involvement did not affect the occurrence of foot pathology. Further research is required on the impact of the extent of any femoral or tibial deformity on foot symptoms and pathology. Biomechanical studies of the forces and motion in the foot related to different degrees of femoral and tibial deformity might also help determine the impact of deformity on foot pathology.

A clinical trial of specialist footwear for patients with rheumatoid arthritis

OBJECTIVES

The structural and functional changes in the RA foot often affect the patient's gait and mobility, impacting on the patient's quality of life. Successful management of these foot pathologies and resultant problems can involve the provision of specialist therapeutic footwear. The aim of the study was to evaluate the value of a new footwear design based on patients' opinions compared with a traditional footwear design.

METHOD

A total of 80 patients with RA of 5 yrs or more duration, foot deformity, difficulty in being able to obtain suitable retail footwear and self-reported foot pain were recruited. Patients were randomly assigned to either an intervention group (new design) or the control group (traditional design). Patients completed two specific health-related quality of life scales (Foot Health Status Questionnaire and the Foot Function Index) at baseline and after 12 weeks.

RESULTS

Only 36 patients completed the trial. Ten refused the footwear outright and 34 withdrew from the study after the footwear was supplied, due to either non-footwear related problems or reasons related to the footwear. Both the specific health-related quality of life scales demonstrated significant improvement from baseline to week 12 with the intervention group (P < 0.05). There was no significant difference in both specific health-related quality of life scales after week 12 with the traditional group (P > 0.05).

CONCLUSIONS

Improvement in pain and patient satisfaction with the new design of footwear for patients with RA over the traditional design indicates the importance of patient involvement in the design process and throughout the process of supplying and monitoring the footwear. The fact that the new-design shoe was based on patients' involvement in the design process in a previous study may be the most important factor in its success. In order to meet the clinical goals of this footwear the patients need to wear them, and to achieve this the patients' requirements need to be acknowledged.

Clinical and experimental models of the midtarsal joint: proposed terms of reference and associated terminology

Recent debate and literature have provided impetus to the growing body of thought that we should not model the midtarsal joint as having two simultaneous axes of rotation but as having a single instantaneous axis of rotation. Building on this concept, we present new reference terminology and propose that descriptions of midtarsal joint kinetics and kinematics relate to moments and motion in the cardinal body planes as defined by the x-, y-, and z-axes of the local reference system of the calcaneus. This replaces the existing terminology that describes the oblique and longitudinal axes for the midtarsal joint. The purpose of the new terms of reference and terminology is to aid in the communication of ideas and concepts regarding the biomechanics of the midtarsal joint among clinicians and between researchers and clinicians. It will also allow integration of the midtarsal joint into the emerging biomechanical model of the lower limb, promote consistency in discussions of the joint, and ease understanding of the interrelationships between the kinetics and the kinematics of the articulations in the foot and lower limb and their relationship to pathology and clinical practice.

Patient perceptions of stock footwear design features

Patients with diseases which impact on foot health, for example diabetes and rheumatoid arthritis, are known to have some benefit from prescribed stock footwear with regards to clinical outcomes. Achieving this is not just about getting the footwear designed and fitted to meet the clinical needs, but it also requires that the patient wears the shoes. This means meeting the non-clinical needs or criteria of patients. The aim of this study was to compare perceptions of the same footwear between patients with diabetes and patients with rheumatoid arthritis (RA) with regard to specific design features. Fifty-four patients with RA and 40 patients with diabetes who required prescription footwear were asked to identify issues of importance, and to assess the features of five different pairs of stock footwear using a Likert scale scoring form. There was a difference between the RA and the diabetes groups with regards their overall requirements from the footwear with comfort being a priority in RA and style a priority for diabetes. Both groups rated the same footwear as overall best from the selection, but the scores suggest that there were features with the 'best' shoe which were not acceptable suggesting that even the 'best' shoe was a compromise This possibly indicates that existing footwear ranges do not meet all the patients' requirements. Patients have different perceptions with regard to what is important to them in terms of footwear with regards to the specific features of the footwear and one of the influences appears to be the underlying systemic disease. Patient-based criteria may be an important consideration in the design of the footwear.

Automated Design of Robust Discriminant Analysis Classifier for Foot Pressure Lesions Using Kinematic Data

In the recent years, the use of motion tracking systems for acquisition of functional biomechanical gait data, has received increasing interest due to the richness and accuracy of the measured kinematic information. However, costs frequently restrict the number of subjects employed, and this makes the dimensionality of the collected data far higher than the available samples. This paper applies discriminant analysis algorithms to the classification of patients with different types of foot lesions, in order to establish an association between foot motion and lesion formation. With primary attention to small sample size situations, we compare different types of Bayesian classifiers and evaluate their performance with various dimensionality reduction techniques for feature extraction, as well as search methods for selection of raw kinematic variables. Finally, we propose a novel integrated method which fine-tunes the classifier parameters and selects the most relevant kinematic variables simultaneously. Performance comparisons are using robust resampling techniques such as Bootstrap 632+ and k-fold cross-validation. Results from experimentations with lesion subjects suffering from pathological plantar hyperkeratosis, show that the proposed method can lead to approximately 96% correct classification rates with less than 10% of the original features.

Regression Techniques for the Prediction of Lower Limb Kinematics

This work presents a novel and extensive investigation of mathematical regression techniques, for the prediction of laboratory-type kinematic measurements during human gait, from wearable measurement devices, such as gyroscopes and accelerometers. Specifically, we examine the hypothesis of predicting the segmental angles of the legs (left and right foot, shank and thighs), from rotational foot velocities and translational foot accelerations. This first investigation is based on kinematic data emulated from motion-capture laboratory equipment. We employ eight established regression algorithms with different properties, ranging from linear methods and neural networks with polynomial support and expanded nonlinearities, to radial basis functions, nearest neighbors and kernel density methods. Data from five gait cycles of eight subjects are used to perform both inter-subject and intra-subject assessments of the prediction capabilities of each algorithm, using cross-validation resampling methods. Regarding the algorithmic suitability to gait prediction, results strongly indicate that nonparametric methods, such as nearest neighbors and kernel density based, are particularly advantageous. Numerical results show high average prediction accuracy (ρ=0.98∕0.99,RMS=5.63°∕2.30°,MAD=4.43°∕1.52° for inter∕intra-subject testing). The presented work provides a promising and motivating investigation on the feasibility of cost-effective wearable devices used to acquire large volumes of data that are currently collected only from complex laboratory environments.

Sagittal plane compensations for artificially induced limitation of the first metatarsophalangeal joint: a preliminary study

This study was undertaken to establish whether reduced dorsiflexion at the first metatarsophalangeal joint affects sagittal plane kinematics at the ankle, knee, and hip. Twenty individuals with symptom-free metatarsophalangeal joints were studied as they walked with and without an insole designed to restrict first metatarsophalangeal joint dorsiflexion. Sagittal plane kinematics at the ankle, knee, and hip were compared in the two conditions. When walking with the insole, the ankle was more dorsiflexed during late midstance and less plantarflexed during propulsion, the knee was more flexed during midstance, and the hip was less extended during late midstance. This evidence of a link between the first metatarsophalangeal joint and the kinematics of the proximal joints demonstrates the potential for the clinical entities of hallux rigidus and hallux limitus to influence gait and justifies more detailed study of this relationship.

Effect of foot orthoses on the kinematics and kinetics of normal walking gait

Despite their wide clinical application and success, our understanding of the biomechanical effects of foot orthoses is relatively limited. The aim of this study was to assess the effect of medially wedged and laterally wedged foot orthoses on the kinematics and joint moments of the rearfoot complex, knee, hip and pelvis and the ground reaction forces. The principal effect of the foot orthoses was on the rearfoot complex, where significant changes in joint rotations and moments were observed. Medially wedged orthoses decreased rearfoot pronation and increased the laterally directed ground reaction force during the contact phase, suggesting reduced shock attenuation. The laterally wedged orthoses increased rearfoot pronation and decreased the laterally directed ground reaction force during the contact phase, suggesting increased shock attenuation. The effects of the orthoses on knee, hip and pelvis kinematics were generally minimal. In view of the minimal effect the orthoses had on joints proximal to the foot, it is suggested that the orthoses may have additional effects on the passive and active soft tissues of the lower limb and it is these changes that result in the documented clinical success.