EPIDEMIOLOGY: The magnitude and the type of lower leg injuries observed in realworld frontal accidents were investigated from the updated APR database. No significant difference of the injury risk was observed in the foot and ankle area neither between the right and left driver feet, nor between drivers and passengers. Although the foot-ankle injury risk linearly increased with footwell intrusion, 28% of the total number of injuries was observed to occur with a footwell intrusion smaller than 50 mm.
BIOMECHANICS: A total sample of 25 fresh amputated human legs were quasistatically tested in inversion, eversion and dorsiflexion in a simulated tensed state. Muscle tension was simulated by applying a constant tensile force in the Achilles tendon. The calcaneus was forced to rotate either in the sagittal or in the frontal plane. The average injury thresholds, the biomechanical responses and the positions of the joint centers of rotation were determined for the ankle and subtalar joints in inversion, eversion and dorsiflexion. Additive tests were performed to assess the midfoot compliance.