Deborah E Turner

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.

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.

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.

Frequent discordance between clinical and musculoskeletal ultrasound examinations of foot disease in juvenile idiopathic arthritis.

To evaluate the levels of agreement from independent clinical examination (CE) by a pediatric rheumatologist and podiatrist and an ultrasound (US) examination of articular and periarticular foot disease in juvenile idiopathic arthritis (JIA).

Tibialis posterior in health and disease: a review of structure and function with specific reference to electromyographic studies

Tibialis posterior has a vital role during gait as the primary dynamic stabiliser of the medial longitudinal arch; however, the muscle and tendon are prone to dysfunction with several conditions. We present an overview of tibialis posterior muscle and tendon anatomy with images from cadaveric work on fresh frozen limbs and a review of current evidence that define normal and abnormal tibialis posterior muscle activation during gait. A video is available that demonstrates ultrasound guided intra-muscular insertion techniques for tibialis posterior electromyography.Current electromyography literature indicates tibialis posterior intensity and timing during walking is variable in healthy adults and has a disease-specific activation profile among different pathologies. Flat-arched foot posture and tibialis posterior tendon dysfunction are associated with greater tibialis posterior muscle activity during stance phase, compared to normal or healthy participants, respectively. Cerebral palsy is associated with four potentially abnormal profiles during the entire gait cycle; however it is unclear how these profiles are defined as these studies lack control groups that characterise electromyographic activity from developmentally normal children. Intervention studies show antipronation taping to significantly decrease tibialis posterior muscle activation during walking compared to barefoot, although this research is based on only four participants. However, other interventions such as foot orthoses and footwear do not appear to systematically effect muscle activation during walking or running, respectively. This review highlights deficits in current evidence and provides suggestions for the future research agenda.

Methodological considerations for a randomised controlled trial of podiatry care in rheumatoid arthritis: lessons from an exploratory trial

BackgroundWhilst evidence exists to support the use of single treatments such as orthoses and footwear, the effectiveness of podiatry-led care as a complex intervention for patients with rheumatoid arthritis (RA) related foot problems is unknown. The aim of this study was to undertake an exploratory randomised controlled parallel arm clinical trial (RheumAFooT) to inform the design and implementation of a definitive trial and to understand the potential benefits of this care.MethodsPatients with a definite diagnosis of RA, stable drug management 3 months prior to entry, and a current history of foot problems (pain, deformity, stiffness, skin or nail lesions, or footwear problems) were recruited from a hospital outpatient rheumatology clinic and randomised to receive 12 months of podiatry treatment or no care. The primary outcome was change in foot health status using the impairment/footwear (LFISIF) and activity limitation/participation restriction (LFISAP) subscales of the Leeds Foot Impact Scale. Disease Activity Score (DAS), Health Assessment Questionnaire (HAQ) score and walking speed (m/s) were also recorded.ResultsOf the 80 patients identified, 64 patients were eligible to participate in the pilot and 34 were recruited. 16 patients were randomised to receive podiatry led foot care and 18 received no care. Against a backdrop of stable disease (DAS and HAQ scores), there was a statistically significant between group difference in the change in foot health status for foot impairment (LFISIF) but not activity/participation (LFISAP) or function (walking speed) over 12 months. In the podiatry arm, 1 patient declined treatment following randomisation (did not want additional hospital visits) and 3 self-withdrew (lost to follow-up). Patients received an average of 3 consultations for assessment and treatment comprising routine care for skin and nail lesions (n = 3), foot orthoses (n = 9), footwear referral to the orthotist (n = 5), and ultrasound guided intra-articular steroid injection (n = 1).ConclusionIn this exploratory trial patients were difficult to recruit (stable drug management and co-morbid disease) and retain (lack of benefit/additional treatment burden) but overall the intervention was safe (no adverse reactions). Twelve months of podiatry care maintained but did not improve foot health status. These observations are important for the design and implementation of a definitive randomised controlled trial.Trial RegistrationISRCTN: 01982076

A reliability study of biomechanical foot function in psoriatic arthritis based on a novel multi-segmented foot model

The objective of this study was to determine the within-and between-day reliability of spatio-temporal, plantar pressure, kinematic and kinetic measurements based on a novel, seven segment foot model applied in patients with Psoriatic Arthritis (PsA). Nine PsA patients and matched healthy adult controls underwent three-dimensional gait analysis on two occasions, one week apart using a seven segment foot model. A core-set of functional variables including inter-segment kinematics, kinetics, spatio-temporal and plantar pressure distribution were analysed using the coefficient of multiple correlation (CMC), Bland-Altman plots, intraclass correlation coefficients (ICC) and the standard error of measurement (SEM). Results showed excellent within- and between-day reliability for intersegment kinematic and kinetic data patterns with CMC values typically greater than 0.950 in a clinically stable cohort of PsA patients. Between-day reliability ranged from poor to excellent for absolute CMC values. Corrected CMC values were consistently higher across all variables ranging from fair-to-good to excellent. ICC values indicated excellent reliability for discrete spatio-temporal, plantar pressure, and ankle moment and power variables for both groups. Reliability for ground reaction forces and kinematic discrete variables ranged from fair-to-good to excellent. Standard error of measurement values ranged from 0.7° to 3.0° for discrete kinematic variables across both groups with greater variability in the PsA patients. In conclusion, intersegment kinematics and kinetics as well as spatio-temporal and plantar pressure can be reliably measured in PsA patients using a novel seven segment foot model. Some discrete kinematic variables have poor reliability and should not be used in prospective cohort and intervention studies.

Foot problems in psoriatic arthritis: high burden and low care provision

Global functional and disability are equivalent for psoriatic arthritis (PsA) and rheumatoid arthritis (RA) despite lower levels of peripheral joint damage in PsA for equivalent disease duration.1 Turner et al 2 have recently shown that RA is associated with moderate to high levels of foot and ankle-related impairment and disability. We have extended this observation to patients with PsA and included provision of foot care. A total of 104 consecutive patients with PsA (60 women, 44 men) of mean (SD) age 51 (12) years and a mean disease duration of 10 (9) years were assessed by a single clinician (DET). Foot and ankle-related impairment and disability were measured using …

Protocol for the Foot in Juvenile Idiopathic Arthritis trial (FiJIA): a randomised controlled trial of an integrated foot care programme for foot problems in JIA

BackgroundFoot and ankle problems are a common but relatively neglected manifestation of juvenile idiopathic arthritis. Studies of medical and non-medical interventions have shown that clinical outcome measures can be improved. However existing data has been drawn from small non-randomised clinical studies of single interventions that appear to under-represent the adult population suffering from juvenile idiopathic arthritis. To date, no evidence of combined therapies or integrated care for juvenile idiopathic arthritis patients with foot and ankle problems exists.Methods/designAn exploratory phase II non-pharmacological randomised controlled trial where patients including young children, adolescents and adults with juvenile idiopathic arthritis and associated foot/ankle problems will be randomised to receive integrated podiatric care via a new foot care programme, or to receive standard podiatry care. Sixty patients (30 in each arm) including children, adolescents and adults diagnosed with juvenile idiopathic arthritis who satisfy the inclusion and exclusion criteria will be recruited from 2 outpatient centres of paediatric and adult rheumatology respectively. Participants will be randomised by process of minimisation using the Minim software package. The primary outcome measure is the foot related impairment measured by the Juvenile Arthritis Disability Index questionnaires impairment domain at 6 and 12 months, with secondary outcomes including disease activity score, foot deformity score, active/limited foot joint counts, spatio-temporal and plantar-pressure gait parameters, health related quality of life and semi-quantitative ultrasonography score for inflammatory foot lesions. The new foot care programme will comprise rapid assessment and investigation, targeted treatment, with detailed outcome assessment and follow-up at minimum intervals of 3 months. Data will be collected at baseline, 6 months and 12 months from baseline. Intention to treat data analysis will be conducted.A full health economic evaluation will be conducted alongside the trial and will evaluate the cost effectiveness of the intervention. This will consider the cost per improvement in Juvenile Arthritis Disability Index, and cost per quality adjusted life year gained. In addition, a discrete choice experiment will elicit willingness to pay values and a cost benefit analysis will also be undertaken.Trial RegistrationTrial registration number: UKCRN5045

Measurement of functional heel pad behaviour in-shoe during gait using orthotic embedded ultrasonography

The ability to measure the functional behaviour of the plantar heel pad is clinically relevant in dystrophic or pathological heel conditions and may help to inform the design and development of interventions that attempt to restore normal function. In this study we present a novel technique which utilises orthotic heel inserts with an embedded ultrasound (US) transducer to allow the functional, dynamic behaviour of the heel pad to be measured in-shoe during gait. The aim of this study was to demonstrate feasibility of the technique, determine the reproducibility of measurements, and to compare the effects of two orthotic inserts: (i) a flat orthotic heel raise and (ii) a contoured heel cup insert on the behaviour of the heel pad during gait. Dynamic compression of the heel pads of 16 healthy participants was recorded during treadmill walking and combined with plantar pressure measurements to allow stiffness and energy disappation ratio (EDR) to be estimated. Inter-session reliability of the US measurements was found to be excellent (ICC2,1=0.94-0.95), as was inter-rater reliability (ICC2,1=0.89). Use of the heel cup insert significantly reduced the maximum compression of the heel pad (p<0.0001) as well as the overall stiffness of the pad (p<0.001). There was no change in EDR (p=0.949). In-shoe embedded US is a reliable method to establish person-specific functional geometry of plantar soft tissues. Use of a contoured heel cup reduces the compression of the mid portion of the heel pad.