Twelve 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.
This model was adapted from the original model proposed by Hyslop et al. [23] previously to measure foot function in adults with psoriatic arthritis (See supplementary online material for full model description), and was selected for use on the basis that JIA is an inflammatory arthropathy with similar disease features.
Participants will complete the primary outcome measure (Foot Function Index pain sub-scale) prior to randomisation and at 12 weeks post randomisation.
Fourteen patients with JIA (mean (standard deviation) age of 12.4 years (3.2)) and a history of foot disease and 10 healthy children (mean (standard deviation) age of 12.5 years (3.4)) underwent three-dimensional gait analysis and plantar pressure analysis to measure biomechanical foot function.
The Manchester Foot Pain and Disability Index (MFPDI) is a 19 item tool developed to measure foot pain and foot related function in patients with foot pain [ 7].
The most widely used scale for measuring the clinical outcomes after this procedure, the American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal Interphalangeal scale, has not been adequately validated and does not measure specific foot functions.
Over these 14 instruments, the 4 clinimetric qualities (content validity, construct validity, reliability, and responsiveness) were only reached by the Foot and Ankle Ability Measure, the Foot Function index, the Foot Health Status Questionnaire, the Lower Extremity Function Scale, and the Sports Ankle Rating System quality of life measure[ 4].
Integration of objective biomechanical measures of foot function into the design process for insoles has been shown to provide enhanced plantar tissue protection for individuals at-risk of plantar ulceration.
There has been an increasing use of gait analysis as an objective measure of foot function in RA [ 8- 13].
Recent reviews of measures of foot function, foot health and foot pain indicate that few have undergone adequate evaluation of responsiveness, thereby limiting their use in clinical trials [ 6- 11].
