The relationship of pain and deformity of the rheumatoid foot to gait and an index of functional ambulation.

We evaluated the relationships among pain, structural deformity of the foot, 4 variables of gait, and an index of functional ambulation in 31 patients with rheumatoid arthritis. We saw significant correlations between the ambulation index and all gait variables (p less than 0.005). For the group as a whole, pain in the foot did not correlate with structural deformity. However, when patients were grouped according to the relative preponderance of pain or deformity and duration of disease, we found correlations between the sites of pain and deformity. Pain in the lower extremity, and the knee or hindfoot separately, showed correlations with functional ambulation. Foot deformity did not correlate with functional ambulation at all. Foot pain correlated well with velocity and especially stride length (p less than 0.005), and not as well with cadence and double stance time. Fewer correlations were seen between foot deformity and gait. In general, hindfoot disease was associated with greater impairment of gait and mobility than forefoot disease.