First ray joint limitation, pressure, and ulceration of the first metatarsal head in diabetes mellitus.

Measurements of first ray mobility, pressure, and other variables were made on 19 diabetic patients with a history of ulceration at the first metatarsal head, 20 diabetic patients with a history of ulceration at other locations of the forefoot, 19 matched diabetic controls, and 19 matched nondiabetic controls. Patients with a history of first metatarsal head ulceration had significantly less first ray mobility and significantly higher pressure at the first metatarsal head compared with the other groups. Regression analysis found a moderate inverse linear relationship between first ray dorsiflexion and peak pressure at the first metatarsal head (R2 = 0.46, P < .0001). Results showed that sensory loss, duration of diabetes, and limited range of motion at the hip, ankle, and foot were related to ulcerations at all forefoot locations, Limited first ray mobility and high pressure at the first metatarsal head were related to ulcerations only at the first metatarsal head location.