Our hypothesis in this study was that significant forces act on the fifth metatarsal during certain maneuvers commonly performed while playing basketball and that medial arch support influences these forces. Eleven male collegiate basketball players participated in this study. Electronic pressure sensors capable of dynamic readings were inserted into the players' shoes, and surface electromyographic (EMG) electrodes were placed over the peroneus longus and brevis muscles. The players performed 3 common maneuvers postulated to place maximal stress on the fifth metatarsal. The maneuvers were performed in a standard basketball shoe, then in a shoe with an orthosis supporting the arch. During each of these maneuvers, EMG activity of the ankle everters was recorded, along with maximal force, total work, and time elapsed beneath the fifth metatarsal.