Thesis (M.Sc.(Sports Medicine))--University of the Witwatersrand, Faculty of Health Sciences, 2014. / Within the context of sports medicine, biomechanical corrective custom foot orthoses are utilised as a treatment intervention to correct pathological gait disorders. In order to manufacture such corrective devices a replicate model of the patients’ foot needs to be obtained. This study aimed to assess both the inter-rater reliability and the intra-rater repeatability of a semi weight bearing foot modelling technique employing a three dimensional white light surface foot scanner. The sample cohort included twenty healthy male and female subjects with ages ranging from 18-70 years. Six qualified Podiatrists were utilised as raters to perform the foot placements on the white light scanner. All raters and participants were given a ten minute training session to familiarise them with the equipment and scanning procedure. The subjects’ left foot was marked and raters positioned and scanned the left foot three times. Digital foot parameter measurements of medial arch height, forefoot width, foot length and rearfoot width were recorded and analysed. The results from this study showed high inter-rater reliability with intraclass correlation coefficients ranging from 0.997 to 1.00 with the specified foot parameter measurements. Intra-rater repeatability of the same specified foot parameter measurements demonstrated good repeatability with Pearson coefficients of correlation values ranging from 0.973 to 0.997. The assessment of the reliability of computerised digital white light scanning as an integral first step in the manufacture of custom foot orthoses has a direct effect on Podiatric practice and the outcomes of patient treatments with this therapeutic modality.

This thesis investigates the three-dimensional kinematics at the ankle joint complex in rheumatoid arthritis. Previous studies have identified the rearfoot as a common site for inflammatory activity in rheumatoid arthritis resulting in painful and disabling deformity for which there are no proven interventions. A generic electromagnetic tracking system was developed to undertake three-dimensional kinematics at the ankle joint complex in the bare and shod foot during gait. A joint simulator was designed, manufactured and commissioned in house to test the accuracy of the system. The results indicated errors of less than 1° in rotation and 1 mm in position measurements. Clinical testing of the measurement system was undertaken in both normal healthy adults and rheumatoid arthritis subjects. The technique was able to measure the characteristic three-dimensional kinematics for the ankle joint complex in the normal subjects and detected accurately abnormal angular rotations in the rheumatoid arthritis group. In both cohorts the within day repeatability of the measurements were good, and over a longer period data were stable in the rheumatoid arthritis group allowing the technique to be used in longitudinal studies. Finally, skin movement artefact where the electromagnetic sensor is attached on the heel was investigated using a magnetic resonance imaging technique and found to be less than 1° across the range of motion for the joint complex. Kinematic measurements were undertaken in two cohorts of rheumatoid arthritis subjects randomised to receive or not custom manufactured foot orthoses to correct early valgus heel deformity. The orthoses were constructed in rigid carbon graphite and modified to offer the correct degree of movement control for each patient. Kinematic data were compared between the rheumatoid arthritis groups and that measured from an age- and sex-matched healthy adult population. In both rheumatoid arthritis groups abnormal kinematics were easily detected with significant alteration of inversion/eversion and internal/external rotation. With foot orthoses the inversion/eversion angular rotations were almost fully restored to normal, but little effect was observed for internal/external rotation. The rheumatoid arthritis patients underwent repeat kinematic measurement over a period of 30-months. In the control group the angular rotations improved slightly from baseline, although in comparison with normal healthy population remained abnormal. In the intervention group the orthotic control of inversion/eversion was sustainable for 30 months. Furthermore, coupling between inversion/eversion and internal/external rotation was partially restored towards the end of the study. In barefoot walking the intervention group demonstrated a substantial correction of the deformity in the frontal plane. It was attempted to explain the results in terms of soft-tissue laxity and adaptation following correction of joint deformity. Three-dimensional kinematic measurements were also conducted at the knee and calcaneotalonavicular joint complex. Abnormal rotations and orthotic response were demonstrable at these joints but with less satisfactory results because of technical limitations of the measurement technique. Plantar pressure distribution was also studied using an in-shoe measurement technique. Custom designed orthoses were found to alter the pressure and force distribution at the interface with the foot. The largest effects were observed at the heel and midfoot regions and these were sustainable and significantly different from the non-intervention control group. The clinical effectiveness of the foot orthoses was also evaluated. A pragmatic randomised controlled trial was undertaken and serial measurements of foot pain and disability, using the Foot Function Index conducted at baseline and 3,6 12,18,24 and 30-months. The results revealed an immediate and significant reduction in foot pain and disability with foot orthoses. Minor adverse reactions were reported but overall comfort levels and compliance were high. The overall reduction in foot pain and disability was sustained up to 30 months.

The development of prescription methods and evaluation of biomechanical performance of bespoke orthoses has been a source of research for the last 40 years. What started as anecdotal and experience–led knowledge has evolved into a more quantifiable paradigm utilising state of the art technologies commonly found in other high-precision industries. The manufacturing challenges associated with such customised products have been driven by the requirement to produce small (often one-off) batches, bespoke for the end user. The introduction of precise scanning equipment and CAD/CAM systems to the podiatry community is enabling the accurate and repeatable manufacture of orthoses that were previously predominantly hand crafted and shaped. Although these traditional production methods are still in use today, the advantages that scanning and CAD/CAM provide mean they are rapidly being adopted. Today, CNC machining and additive manufacture provide state of the art manufacturing methods for bespoke insoles prescribed and modelled in a CAD environment. However, the limitations of both these manufacturing methods relate to the materials that can be processed, which becomes problematic when manufacturing soft or semi-rigid orthoses. Hence an opportunity exists to develop a new and innovative method for processing foamed polymer materials that are typically vacuum formed today. This research explores the prescription and analysis methods attributed to insole design for sporting applications using specific sports shoes. The insole designs encompass material selection to deliver a product that provides control and function whilst also providing a degree of impact attenuation, recognising the dynamic and high-impact nature of the sportsspecific movements. Consideration is also given to the types of activities that function with the device. This research analyses characteristic plantar pressures experienced whilst undertaking sports-specific movements to aid in the prescription of bespoke insoles for the chosen sport. A design methodology encompassing state of the art scanning technologies and anthropometric measurements provides a repeatable and accurate means to produce the required geometry for a bespoke sport and symptom-specific insole. The research also presents the concept of cryogenic machining, a novel manufacturing method for the CNC machining of foamed polymers. The materials are cooled with the use of a liquid cryogen to below their glass transition temperature at which point relative motion at a molecular level is significantly reduced, providing a rigid and machineable form. This, along with a bespoke cryogenic facility encompassing a vertical 3 axis CNC machining centre, a pressurised liquid nitrogen dewar connected to a bespoke-designed fixture by a vacuum jacketed pipe, enables the dual-sided machining of an amorphous material, something which is not possible with conventional processes. The major contributions of this work are the design methodology to prescribe a sport and symptom-specific insole using state of the art scanning and CAM methods, the design and manufacture of a fixture to facilitate the dual-sided machining of a customised insole and the subsequent testing of the designs in a laboratory environment. In addition the research utilises motion analysis, force plate data and pressure measurement to explore the effects of the insoles on the kinetics, kinematics and peak plantar pressures at discrete anatomical regions during sport-specific manoeuvres.

Background: Diabetic peripheral neuropathy (DPN) is diagnosed clinically as a loss of sensation in the feet and affects over 2 million people in the UK. One of the functional effects of DPN is a decrease in standing stability giving rise to a risk of falls. In an attempt to stabilise in the mediolateral direction, people with DPN frequently walk with a wider base of support and stand with a larger stance width. This is often seen in the elderly and is not always beneficial for stability contributing to falls risk. Standing balance requires the integration of sensory information from somatosensory, vestibular and visual systems. Alterations in distal sensory input may result in a re-weighting of the effectiveness of remaining sensations in mediating a stabilising postural response; termed sensory re-weighting. Alterations in posture such as adopting a wider stance width and wearing Ankle Foot Orthoses (AFOs) may also affect sensory input as well as altering the mechanics of the ankle and hip joints. The impact of distal sensory loss on the sensory control of balance in people with DPN compared to the healthy population is unknown. Moreover, it is not known whether standing balance or the sensory control of balance is affected by the adoption of an increased stance width and wearing (AFOs) that restrict mediolateral ankle motion. A better understanding of the mechanisms underlying balance dysfunction in diabetic peripheral neuropathy and how it might be manipulated could inform the development of future interventions to improve balance. Aim: To explore the effects of ankle foot orthoses and stance width on standing balance and the sensory control of mediolateral balance in people with DPN and healthy controls. Objectives: To assess how mediolateral postural stability and the sensory control of balance is affected by (a) AFO use and alterations in stance width in healthy participants (study 1) (b) acute distal sensory loss in healthy participants (study 2) (c) chronic sensory loss in people with DPN and how this in turn is modulated by AFO use and alterations in stance width (study 3). Methods: Postural stability and the response to selective muscle vibration that stimulates muscle spindle afferents was measured by 3D motion analysis. Study 1 investigated the effects of stance width and AFOs on postural sway and the response to selective hip proprioception stimulation induced by vibration of the hip abductors in healthy participants. Study 2 investigated the effect of an acute reduction of somatosensory information induced by cooling in healthy participants on the response to ankle evertor and hip abductor vibration. This provided a model of the acute effects of sensory loss. Study 3 compared healthy people with people with chronic DPN. It investigated the impact on stance stability and whether there was a change in the postural response (gain) to ankle evertor and hip abductor vibration. It further explored the effect of altering the stance width and wearing an AFO on stability and the postural response to hip abductor vibration. Results: Study 1: In healthy controls postural sway was significantly reduced when wearing an ankle foot orthoses and when standing at wider stance widths. Whilst this was also seen during balance perturbation, trunk motion increased at larger stance widths. This could be the result of the AFO restricting ankle motion and affecting the interpretation of the hip vibratory input by the postural control system. Study 2: Experimental reduction in distal sensation by cooling resulted in a reduction in postural responses to ankle evertor muscle vibration. Conversely postural responses at the level of the hip, to proximal (hip) muscle vibration, significantly increased. Study 3: Baseline sway velocity was higher in people with DPN compared to healthy controls. Postural strategies were modified in the DPN group, with increased motion at more proximal segments of the shoulder and head. In both groups, AFO and stance width significantly reduced baseline sway velocity, and the size of postural responses (translations) to hip abductor muscle vibration. Conclusion: Alterations in stance width and the use of AFOs can affect postural sway and the response to selective proprioceptive stimulation. Whilst acute reductions in distal sensory loss are associated with sensory re-weighting of distal and proximal proprioceptive information this is not seen in people with chronic DPN, possibly resulting from long term adaptive changes in the multi-sensory control of balance. Novel differences were found in postural strategies between healthy and DPN groups. The increase in head and trunk motion in people with DPN may have a negative impact on visual acuity and therefore a risk factor for falls. In people with diabetic peripheral neuropathy AFOs and increased stance width led to a reduction in postural response size and postural sway. The effect of AFO on sway velocity was more pronounced in those with DPN at smaller stance widths. Clinically this suggests that an AFO could be used in those with diabetic peripheral neuropathy to slow down the velocity of sway and increase stability.

Simulation has not been extensively studied for teaching rehabilitation practitioners technical skills. The purpose of this study is to test the efficacy of an artificial hand as a teaching tool for orthosis-making. Thirty-four participants were randomized into three groups. The first group made five orthoses on a human hand, the second made five orthoses on a model hand, and the third made one orthosis on a human hand. A one-week transfer test consisted of all participants making one orthosis on a human hand. Their performance and orthoses were evaluated using a validated checklist and global rating scale. No differences were found between groups for process-related measures. The model hand group did better on final product measures and had a larger movement time than the other two groups. Practicing on artificial hands is a useful way of learning to make orthoses. Additionally, higher practice volume did not lead to better performance.

Simulation has not been extensively studied for teaching rehabilitation practitioners technical skills. The purpose of this study is to test the efficacy of an artificial hand as a teaching tool for orthosis-making. Thirty-four participants were randomized into three groups. The first group made five orthoses on a human hand, the second made five orthoses on a model hand, and the third made one orthosis on a human hand. A one-week transfer test consisted of all participants making one orthosis on a human hand. Their performance and orthoses were evaluated using a validated checklist and global rating scale. No differences were found between groups for process-related measures. The model hand group did better on final product measures and had a larger movement time than the other two groups. Practicing on artificial hands is a useful way of learning to make orthoses. Additionally, higher practice volume did not lead to better performance.

Athletic pelvic/groin injuries can be difficult to define, diagnose and therefore manage. These injuries are often the result of multifactorial dysfunction, making them susceptible to becoming chronic. Transverse pelvic belts have shown effectiveness in reducing pain and improving function in athletes with pelvic/groin pain, but there may be better alternatives. Exploring different pelvic belt configurations with athletes with pelvic/groin pain confirmed the role of a transverse belt but also found that diagonal belts produced significantly (< 0.05) greater effects upon clinical measures of pain and function. Dynamic elastomeric fabric orthoses (DEFOs) are Lycra®-based orthoses theorised as providing stability and enhancing proprioception. A DEFO was designed to apply diagonal force to the pelvic girdle and mimic transverse belt application. In a series of single case studies the DEFO was found to have beneficial effects upon pain and/or function in selected athletes with pelvic/groin pain. Athletes’ subjective reports suggested that balance and power may have also been positively influenced. Further work exploring appropriate measures of athletic balance led to the investigation of the intra-rater reliability of a functional measure; the multiple single-leg hop-stabilisation test. Good to excellent reliability (ICC = 0.85; CI 0.61-0.90) confirmed this measure as being reliable for use in a future study, and highlighted relationships with other factors such as age and training status. The findings of a pilot RCT indicated that with minor revisions this protocol could be effectively implemented in informing a future RCT. Findings also indicated that the DEFO led to moderate to large effect sizes on clinical measures (d = 0.6-1.1) of active straight leg raise and squeeze test force, and negligible to small effects on measures of power and functional balance (d = 0.1-0.3). This thesis therefore outlines the development and initial evaluation of a novel DEFO for supporting the management of athletic pelvic/groin injury. Further work is required to undertake a fully powered RCT, and to explore the mechanistic action of this DEFO.

Children with cerebral palsy (CP) have a higher than normal O2 uptake (VO2) during walking. While various interventions are used to improve locomotion, little is known about their effect on the metabolic and cardiopulmonary cost of walking. We therefore assessed the effects of one popular intervention, hinged ankle foot orthoses (AFO), on cardiopulmonary and metabolic variables during 2 min of steady state treadmill walking at three speeds: 3 kph, comfortable walking speed (CWS) and fast walking speed (FWS). We also assessed the effect of these braces on comfortable and maximum ground walking speed and on gross motor abilities using the Gross Motor Function Measure. Ten children with spastic diplegic CP (9.01 years ± 2.10) who habitually used hinged AFO participated. Not all children could walk at all speeds on the treadmill however, and some cardiopulmonary and metabolic data on three children were missing due to equipment failure. We performed an ANOVA on data for children who walked at 3 kph and CWS (n=8 for heart rate (HR); n=9 for pulmonary ventilation and metabolic variables) and a t-test on data at FWS (n=9 for HR, n=8 for pulmonary ventilation and metabolic variables). When children wore AFO, absolute VO2 was reduced by 4.6% at 3 kph and by 4.1% at FWS, and absolute VO2 per metre walked by 4.6% and 4.4% at the same speeds, respectively. Adjusting VO2 for body mass, or for resting VO2 or calculating energy expenditure in kJ, revealed the same pattern. Pulmonary ventilation was lower with AFO on by 7.17%, but only at 3 kph. AFO did not affect gross motor abilities. Nor did it affect HR, or the respiratory exchange ratio at any speed, nor any physiologic variable at CWS. We suggest the lower O2 cost may reflect an increase in stability and a corresponding decrease in coactivation of lower limb antagonistic muscles. / Thesis / Master of Science (MSc)

Aim: A study to investigate the potential feasibility (including estimated effect-size), acceptability and health benefits of DEFO and physiotherapy in treatment of spasticity following intramuscular injection of BT. Participants: Adults living in the community with focal spasticity of the upper or lower limb (Modified Ashworth Scale 2-3) recruited at a regional Spasticity Clinic. Intervention: provision of an individually fitted DEFO (worn daily up to 8 hours) usual care and physiotherapy (as required) for 6 weeks. Methods: Mixed methods embedded design feasibility study: Quantitative: Feasibility single-blind RCT: Intervention Group: DEFO intervention protocol, usual care and physiotherapy, Control Group: usual care and physiotherapy. Qualitative: Topic guided interviews of the intervention group and clinicians. Measures: Goal Attainment Scale (GAS) primary measure and secondary measures for function and care benefit; Arm Activity measure (ArmA), Leeds Arm Impact Score (LASIS), VAS for pain, European Quality of Life-5 Dimensions (EQ-5D), gait velocity (10MTT). Variance and fidelity was captured with: DEFO wearing record, Activity Log, clinical records and Physiotherapy modalities. Analysis: ANCOVA adjusted means and statistical comparison for significance of measures (at baseline, after six weeks and twelve weeks) between groups and to inform power calculations. Thematic Analysis of clinician and participant transcribed interviews. Quantitative and qualitative findings were integrated and triangulated to inform a larger study. Results: Participants (n=25) recruited over twelve months, (n=22) completed study. Statistical analysis showed improvements in both groups with greater health benefit in the intervention group with mean difference in the GAS of 12.17 (95% CI: 3.16 to 21.18; p = 0.014) but no statistical significance in the secondary measures. Effect-size was estimated from the GAS findings for 200 per group for a larger study. Physiotherapy modalities for spasticity were linked to 'passive' and 'active' function. Feasibility and acceptability was established with Thematic Analysis providing valuable insight into patient and clinician perspectives on disability. Conclusions: Findings indicated potential added health benefits including carer benefit. Feasibility, acceptability and clinical application of DEFO as a potential new intervention were established. This has implications for future spasticity management with patient benefit for passive and active function. Further research is indicated with a fully powered study (based on the GAS sample results) to evaluate DEFO efficacy in people with spasticity following BT.

INTRODUÇÃO: Estudo prévio do nosso grupo demonstrou que uso de palmilha em cunha medial associada ao estabilizador de tornozelo produz uma melhora clínica na osteoartrite do joelho valgo. No entanto, não existem dados na literatura sobre os efeitos biomecânicos destas órteses. OBJETIVO: Avaliação biomecânica dos pés, de maneira estática e dinâmica na osteoartrite do joelho valgo com a utilização de palmilha em cunha medial associada ao estabilizador de tornozelo. MÉTODO: Um total de 42 pés de 21 mulheres com osteoartrite de joelho bilateral (critérios ACR) e deformidade em valgo > 8 graus, foram avaliadas quanto a dados clínicos e biometria. As pacientes foram avaliadas em esteira ergométrica elétrica com: 1. calçado padrão sem a palmilha (controle), 2. palmilha em cunha medial (com 8 mm de elevação medial no retropé) e 3. com essas palmilhas e estabilizador de tornozelo em neoprene. O sistema FSCAN® versão 3.816, com palmilhas flexíveis e 960 sensores de carga na superfície foi utilizado para obter a força plantar vertical. RESULTADOS: Houve redução no pico de pressão plantar estático (PP) com a utilização da palmilha em cunha (P = 0,001) e com a palmilha e estabilizador (P < 0,001) vs. controle em ambos os lados. Além disso, o uso da palmilha associada ao estabilizador de tornozelo resultou em uma redução mais efetiva neste parâmetro em comparação ao uso somente da palmilha (P = 0,027). A avaliação dinâmica deste parâmetro revelou resultado similar no lado direito, com uma redução mais significativa com o uso da palmilha (P < 0,001) e com palmilha e estabilizador de tornozelo (P < 0,001) em relação ao controle. Não foi observada diferença no lado esquerdo (osteoartrite mais grave). A força vertical máxima estática (FVM) também demonstrou diminuição em ambos os lados com o uso da palmilha (P = 0,001) e palmilha associada ao estabilizador de tornozelo (P < 0,001) em relação ao controle. Além disso, o uso da palmilha associada ao estabilizador de tornozelo resultou em uma redução mais efetiva da força vertical máxima estática em comparação ao uso somente da palmilha (P = 0,041). Da mesma forma, na condição dinâmica, esse parâmetro foi significativamente reduzido com o uso da palmilha associada ao estabilizador de tornozelo em comparação à condição controle (P < 0,001). Também houve redução na FVM entre o uso de palmilha com e sem estabilizador (P = 0,003). A avaliação qualitativa revelou que a órtese altera significativamente a trajetória do vetor de força (P < 0,001). CONCLUSÃO: O uso da palmilha em cunha medial associada ao estabilizador de tornozelo promoveu uma redução no pico de pressão plantar e na força vertical máxima em condições estática e dinâmica, subjacente à melhora clínica na osteoartrite do joelho valgo / INTRODUCTION: We have previously demonstrated a significant clinical improvement in valgus knee osteoarthritis with the use of medial-wedge insole associated with ankle support. There is, however, no data regarding the foot plantar forces underlying this beneficial effect. Objective: Static and dynamic feet plantar biomechanical evaluation of medial-wedge insole associated with ankle support in valgus knee osteoarthritis. METHOD: A total of 42 feet of 21 women with bilateral knee osteoarthritis (ACR criteria), with valgus deformity were evaluated regarding clinical and biometric data. Patients were assessed with: 1. standard shoes without the insoles (control); 2. medial-wedge insole; 3. insoles/neoprene ankle support. The system FSCAN® 3816 version, with flexible soles and 960 load sensors on the surface was used to obtain the foot plantar vertical forces. RESULTS: A decreased peak plantar pressure was observed with insoles (P = 0,001) and insoles/ankle support (P < 0,001) vs. control while standing motionless in both sides. In addition, insoles/ankle support resulted in a more effective reduction in this parameter than solely insoles (P = 0,027). The dynamic evaluation of this parameter revealed a similar finding on the right side with a more significant reduction with use of insoles (P < 0,001) and with insoles/ankle support (P < 0,001) compared to controls. No difference was observed on the left side (more severe OA). The static maximum vertical force was also decreased in both sides with insoles (P = 0,001) and insoles/ankle support (P < 0,001) compared to control. In addition, the later condition provided a more significant reduction in the static maximum vertical force than solely insoles (P = 0,041). Likewise, in the dynamic condition this parameter was significantly reduced with insoles/ankle support compared with control condition (P < 0,001) and solely insoles (P = 0,003). The qualitative evaluation revealed that orthoses significantly changed the center of force shift (P < 0,001). CONCLUSION: We have identified that a reduction in the feet plantar peak and maximum vertical force in valgus knee osteoarthritis in static and dynamic conditions underlies the clinical improvement of medial-wedge insole associated with ankle support