A kinematic study of ankle joint instability due to rupture of the lateral ligaments

Kinematic analysis of patients who have ruptured the ligaments of the ankle joint was performed to evaluate the function of those ligaments. Ten patients with ruptured lateral collateral ligaments and 10 normal volunteers were examined. Patients' ages ranged from 17 to 29, averaging 20.9 years old. We performed kinematic evaluation by a three-dimensional optical analytic technique using surface markers. According to our results, the ankles with lateral ligament injury abnormally pronated and rotated externally at the time of heel strike and abnormally supinated and rotated internally during the acceleration phase.