The Structural Index Score and its relation to foot function, disability and physical performance tests in rheumatoid arthritis (RA) - A cross-sectional study.

OBJECTIVES: To evaluate the Structural Index Score (SIS) - a clinical foot deformity assessment index developed for RA, and to compare its results with foot function, disability and physical performance tests. METHODS: In this cross-sectional study, 104 patients with foot pain were evaluated according to SIS score, subscales (Forefoot SIS and Rearfoot SIS) and items. Results were compared with the Foot Function Index (FFI), the Health Assessment Questionnaire Disability Index (using lower limbs items: LL-HAQ), and physical performance tests: Berg Balance Scale (BBS), the Timed Up and Go test (TUG) and the 5-Time Sit down-to-Stand up Test (SST5). RESULTS: There was a weak correlation of SIS score with FFI and LL-HAQ. Rearfoot SIS was correlated with FFI, LL-HAQ and worse performance in BBS, TUG and SST5. Regarding Rearfoot SIS items, the ankle ROM was correlated to all studied outcomes, the calcaneus varus/valgus was correlated with FFI (total, pain and disability subscales) and the planus/cavus deformity with FFI-pain, HAQ-DI and LL-HAQ. Forefoot SIS did not correlate with any outcome measures. In relation to Forefoot SIS items, hallux valgus was associated with foot function (FFI-total, pain and disability subscales), the MTPs joints subluxation was correlated with FFI-disability subscale, and the 5th MTP exostosis was associated with FFI-pain. CONCLUSION: SIS score was correlated to impaired foot function (FFI) and disability (LL-HAQ). Rearfoot SIS was correlated to worse performance on FFI, LL-HAQ, BBS, TUG and SST5. SIS score index can be a useful tool to evaluate the rheumatoid foot deformities, but a better graduation of foot deformities should add sensitivity to this method.

The effect of foot orthoses on balance, foot function, and mobility in rheumatoid arthritis: A randomized controlled clinical trial.

OBJECTIVES: To compare balance, foot function and mobility in patients with rheumatoid arthritis with and without foot orthoses. DESIGN: Randomized controlled trial. SETTING: Outpatient rheumatology clinic. SUBJECTS: A total of 94 subjects with rheumatoid arthritis were randomized; of these, 81 were included in the analyses (Intervention group: 40; Control group: 41). INTERVENTION: The Intervention Group received custom-made foot orthoses while the Control Group received none intervention. MAIN MEASURE: The "Foot Function Index," the "Berg Balance Scale," and the "Timed-up-and-go Test" were assessed at baseline an after four weeks. The chosen level of significance was P < 0.05. RESULTS: Average (standard deviation) participant age was 56.7 (±10.6) years old and average disease duration (standard deviation) was 11.4 (± 7.2) years. Groups were similar at baseline, except for comorbidity index and race. After four weeks, significant interaction group versus time was observed for Foot Function Index (change: Intervention group: -1.23 ± 1.58; Control group: -0.12 ± 1.16 - P = 0.0012) and for Berg Balance Scale (change: Intervention group: 2 ± 3; Control group: 0 ± 3 - P = 0.0110), but not for the Timed-up-and-go Test (change: Intervention group: -1.34 ± 1.99; Control group: -0.84 ± 2.29 - P = 0.0799). CONCLUSION: Foot orthoses improved foot function and balance in patients with rheumatoid arthritis.