The Cherwell splint: an ankle and foot orthosis for rheumatoid arthritis.

Rheumatoid arthritis often gives rise to painful collapse or partial collapse of the foot into valgus under load-bearing conditions, limiting the subject's ability to walk. However, the ankle joint frequently remains unimpaired. Thus, in serious cases a cosmetic splint is required which supports the foot whilst allowing the ankle to plantarflex and dorsiflex. The Cherwell ankle-foot orthosis has been designed and extensively tested in Oxford and elsewhere during the last four years, and can now be prescribed and supplied from three orthopaedic centres to meet this requirement.