Orthotic management of plantar pressure and pain in rheumatoid arthritis

Objective. To investigate the effectiveness of foot orthoses in the managem ent of plantar pressure and pain in subjects with rheumatoid arthritis. Design. A repeated measures study in which the independent variable was ort hosis design. Dependent variables, including pressure, gait and pain parame ters, were examined using analysis of variance and correlation statistics. Background. The aim of orthotic management of the rheumatoid foot is to rel ieve metatarsalgia through the reduction of metatarsal head pressure. Few s tudies have investigated the relative effectiveness of different orthosis d esigns. To date, no studies have examined the relationship between plantar pressure and second metatarsal head pain in rheumatoid arthritis subjects. Methods. Twelve rheumatoid arthritis subjects with foot involvement and sec ond metatarsal head pain were tested. Four styles of foot orthosis (prefabr icated, standard custom moulded, custom with metatarsal bar, custom with me tatarsal dome) were compared to a shoe only control. An EMED Pedar system w as used to measure plantar pressure during repeated trials of comfortable c adence walking and quiet standing. Reports of subjective pain were recorded for each orthosis as were orthosis preferences. Results. All orthoses significantly reduced pressure beneath the first and second metatarsal heads compared to the shoes only control. The custom moul ded orthosis with metatarsal dome was the most effective orthosis for reduc ing subjective ratings of pain. A significant correlation (r = 0.562) was f ound between ratings of pain and average pressure beneath the second metata rsal head. Conclusions. Results from this study suggest that average pressure measurem ent may be a useful indicator in the management of metatarsalgia in RA, Fur ther study is required to improve understanding of the relationship between rheumatoid foot mechanics and pain.