Recent evidence points toward a weight bearing and dynamic stabilizing function of the distal fibula in ankle joint mechanics. When fibular rotation and translation are restricted, ankle pain during weight bearing and push off often (but not always) results. The case histories of six professional athletes with distal tibial synostosis resulting from internal rotation-inversion injury confirm recent reports of ankle disability resulting from restriction of fibular motion, but suggest that there may be many patients with this lesion who are not disabled. Two patients with incomplete synostosis were asymptomatic, and one with complete synostosis had only occasional pain after vigorous exercise.