James Woodburn

The impact of rheumatoid arthritis on foot function in the early stages of disease: a clinical case series

BackgroundFoot involvement occurs early in rheumatoid arthritis but the extent to which this impacts on the structure and function leading to impairment and foot related disability is unknown. The purpose of this study was to compare clinical disease activity, impairment, disability, and foot function in normal and early rheumatoid arthritis (RA) feet using standardised clinical measures and 3D gait analysis.MethodsTwelve RA patients with disease duration ≤2 years and 12 able-bodied adults matched for age and sex underwent 3D gait analysis to measure foot function. Disease impact was measured using the Leeds Foot impact Scale (LFIS) along with standard clinical measures of disease activity, pain and foot deformity. For this small sample, the mean differences between the groups and associated confidence intervals were calculated using the t distributionResultsModerate-to-high foot impairment and related disability were detected amongst the RA patients. In comparison with age- and sex-matched controls, the patients with early RA walked slower (1.05 m/s Vs 1.30 m/s) and had a longer double-support phase (19.3% Vs 15.8%). In terminal stance, the heel rise angle was reduced in the patients in comparison with normal (-78.9° Vs -85.7°). Medial arch height was lower and peak eversion in stance greater in the RA patients. The peak ankle plantarflexion power profile was lower in the patients in comparison with the controls (3.4 W/kg Vs 4.6 W/kg). Pressure analysis indicated that the RA patients had a reduced lesser toe contact area (7.6 cm2Vs 8.1 cm2), elevated peak forefoot pressure (672 kPa Vs 553 kPa) and a larger mid-foot contact area (24.6 cm2Vs 19.4 cm2).ConclusionAnalysis detected small but clinically important changes in foot function in a small cohort of RA patients with disease duration <2 years. These were accompanied by active joint disease and impairment and disability.

Characterising the clinical and biomechanical features of severely deformed feet in rheumatoid arthritis

PURPOSE Foot deformity is a well-recognised impairment in patients with rheumatoid arthritis (RA) which results in functional disability. Deformity can occur at the rearfoot, midfoot, forefoot or in combination and the impact that site-specific foot deformities has on functional disability is largely unknown. The aim of this study was to describe the clinical and biomechanical characteristics of patients with severe rearfoot, forefoot or combined deformities and determine localised disease impact. METHODS Twenty-eight RA patients with severe forefoot (FF group n=12), rearfoot (RF group n=10) or combined deformities (COMB group n=6) were recruited. Each patient underwent 3D gait analysis and plantar pressure measurements. Localised disease impact and foot-specific disease activity were determined using the Leeds Foot Impact Scale and clinical examination respectively. Comparison was made against a normative control group (n=53). RESULTS Patients in the COMB group walked slowest and the double-support time was longer in the RF and COMB groups compared to those in the FF group. Patients in the RF and COMB group had higher levels of foot-related disability and demonstrated excessive rearfoot eversion and midfoot collapse compared to those in the FF group. Forefoot deformity was associated with reduced toe contact, high forefoot pressures and delayed heel lift. CONCLUSIONS Abnormal gait patterns were identified and were distinguishable among those patients with predominantly forefoot, rearfoot or combined foot deformity.

The use of 3D surface scanning for the measurement and assessment of the human foot

BackgroundA number of surface scanning systems with the ability to quickly and easily obtain 3D digital representations of the foot are now commercially available. This review aims to present a summary of the reported use of these technologies in footwear development, the design of customised orthotics, and investigations for other ergonomic purposes related to the foot.MethodsThe PubMed and ScienceDirect databases were searched. Reference lists and experts in the field were also consulted to identify additional articles. Studies in English which had 3D surface scanning of the foot as an integral element of their protocol were included in the review.ResultsThirty-eight articles meeting the search criteria were included. Advantages and disadvantages of using 3D surface scanning systems are highlighted. A meta-analysis of studies using scanners to investigate the changes in foot dimensions during varying levels of weight bearing was carried out.ConclusionsModern 3D surface scanning systems can obtain accurate and repeatable digital representations of the foot shape and have been successfully used in medical, ergonomic and footwear development applications. The increasing affordability of these systems presents opportunities for researchers investigating the foot and for manufacturers of foot related apparel and devices, particularly those interested in producing items that are customised to the individual. Suggestions are made for future areas of research and for the standardization of the protocols used to produce foot scans.

A systematic review of instruments measuring foot function, foot pain, and foot-related disability in patients with rheumatoid arthritis

OBJECTIVE To compose an inventory of instruments that have been described to measure foot function (i.e., pressure and/or gait parameters), foot pain, and foot-related disability in rheumatoid arthritis (RA), and to investigate the clinimetric quality of these measures. METHODS A systematic search was conducted in Medline, CINAHL, EMBase, and Sportdiscus. Standardized criteria, extended with levels of evidence, were applied to assess the quality of the clinimetric studies and the properties (i.e., reliability, validity, and responsiveness) of the described instruments. RESULTS A variety of measurement instruments were identified. Only 16 instruments have been studied for their measurement properties in RA patients: 7 for assessing foot function, 3 for measuring foot-related disability, and 6 for measuring both foot pain and foot-related disability. Thirteen instruments were rated for reliability, of which 10 were rated positively on different levels of evidence. No positive rating for absolute measurement error was applicable for any of the tests. Internal consistency was reported for 7 instruments; 3 assigned a positive rating. For 2 instruments, Rasch analysis was used to assess the methodologic quality. A positive rating was reported for goodness-of-fit only, not for item calibration. Seven instruments were rated for construct validity, and 3 assigned a positive rating. Only 2 instruments were rated positively for responsiveness. CONCLUSION This review offers a basis for choosing the most appropriate instruments for measuring foot function, foot pain, and foot-related disability in RA patients, both for clinical practice and for research. Further research on the quality of these measures is urgently needed.

Custom foot orthoses for rheumatoid arthritis: A systematic review

To identify and critically appraise the evidence for the effectiveness of custom orthoses for the foot and ankle in rheumatoid arthritis.

The relationship between passive range of motion and range of motion during gait and plantar pressure measurements

Aims  To investigate the relationship between limited joint mobility (LJM; measured both passively and during gait) and plantar pressure measurements.

Embracing additive manufacture: implications for foot and ankle orthosis design

BackgroundThe design of foot and ankle orthoses is currently limited by the methods used to fabricate the devices, particularly in terms of geometric freedom and potential to include innovative new features. Additive manufacturing (AM) technologies, where objects are constructed via a series of sub-millimetre layers of a substrate material, may present the opportunity to overcome these limitations and allow novel devices to be produced that are highly personalised for the individual, both in terms of fit and functionality.Two novel devices, a foot orthosis (FO) designed to include adjustable elements to relieve pressure at the metatarsal heads, and an ankle foot orthosis (AFO) designed to have adjustable stiffness levels in the sagittal plane, were developed and fabricated using AM. The devices were then tested on a healthy participant to determine if the intended biomechanical modes of action were achieved.ResultsThe adjustable, pressure relieving FO was found to be able to significantly reduce pressure under the targeted metatarsal heads. The AFO was shown to have distinct effects on ankle kinematics which could be varied by adjusting the stiffness level of the device.ConclusionsThe results presented here demonstrate the potential design freedom made available by AM, and suggest that it may allow novel personalised orthotic devices to be produced which are beyond the current state of the art.

Tibialis posterior tenosynovitis and associated pes plano valgus in rheumatoid arthritis : electromyography, multisegment foot kinematics, and ultrasound features

To compare electromyographic (EMG), kinematic, kinetic, and ultrasound (US) features of pes plano valgus associated with US‐confirmed tibialis posterior (TP) tenosynovitis in rheumatoid arthritis (RA) and healthy control subjects.

A survey of foot problems in juvenile idiopathic arthritis

BACKGROUND Evidence suggests that foot problems are common in juvenile idiopathic arthritis (JIA), with prevalence estimates over 90%. The aim of this survey was to describe foot-related impairment and disability associated with JIA and foot-care provision in patients managed under modern treatment paradigms, including disease-modifying anti-rheumatic drugs (DMARDs) and biologic therapies. METHODS The Juvenile Arthritis Foot Disability Index (JAFI), Child Health Assessment Questionnaire (CHAQ), and pain visual analogue scale (VAS) were recorded in 30 consecutive established JIA patients attending routine outpatient clinics. Foot deformity score, active/limited joint counts, walking speed, double-support time (s) (DS) and step length symmetry index % (SI) were also measured. Foot-care provision in the preceding 12 months was determined from medical records. RESULTS Sixty-three per cent of children reported some foot impairment, with a median (range) JAFI subscale score of 1 (0-3); 53% reported foot-related activity limitation, with a JAFI subscale score of 1 (0-4); and 60% reported participation restriction, with a JAFI subscale score of 1 (0-3). Other reported variables were CHAQ 0.38 (0-2), VAS pain 22 (0-79), foot deformity 6 (0-20), active joints 0 (0-7), limited joints 0 (0-31), walking speed 1.09 m/s (0.84-1.38 m/s), DS 0.22 s (0.08-0.26 s) and SI +/-4.0% (+/-0.2-+/-31.0%). A total of 23/30 medical records were reviewed and 15/23 children had received DMARDS, 8/23 biologic agents and 20/23 multiple intra-articular corticosteroid injections. Ten children received specialist podiatry care comprising footwear advice, orthotic therapy and silicone digital splints together with intrinsic muscle strengthening exercises. CONCLUSION Despite frequent use of DMARD/biologic therapy and specialist podiatry-led foot care, foot-related impairment and disability persists in some children with JIA.

A clinically applicable six-segmented foot model.

We describe a multi‐segmented foot model comprising lower leg, rearfoot, midfoot, lateral forefoot, medial forefoot, and hallux for routine use in a clinical setting. The Ghent Foot Model describes the kinematic patterns of functional units of the foot, especially the midfoot, to investigate patient populations where midfoot deformation or dysfunction is an important feature, for example, rheumatoid arthritis patients. Data were obtained from surface markers by a 6 camera motion capture system at 500 Hz. Ten healthy subjects walked barefoot along a 12 m walkway at self‐selected speed. Joint angles (rearfoot to shank, midfoot to rearfoot, lateral and medial forefoot to midfoot, and hallux to medial forefoot) in the sagittal, frontal, and transverse plane are reported according to anatomically based reference frames. These angles were calculated and reported during the foot rollover phases in stance, detected by synchronized plantar pressure measurements. Repeated measurements of each subject revealed low intra‐subject variability, varying between 0.7° and 2.3° for the minimum values, between 0.5° and 2.1° for the maximum values, and between 0.8° and 5.8° for the ROM. The described movement patterns were repeatable and consistent with biomechanical and clinical knowledge. As such, the Ghent Foot model permits intersegment, in vivo motion measurement of the foot, which is crucial for both clinical and research applications.