Influence of ankle ligaments on tibial rotation: an in vitro study.

The purpose of this study was to clarify the role of the ankle ligaments in controlling the tibial rotation for different foot positions. A 6 degrees of freedom device was constructed for in vitro simulation of this movement transfer during the support phase of gait. Tibia rotation angle was measured for different foot positions and vertical loads, while the ligament integrity was modified. Data were collected from eight legs of four different cadavers. The results showed that vertical loading is unimportant to influence tibial rotation, while the lateral ankle ligaments have significant influence, especially during eversion. It was concluded that chronic partial or total lateral ankle instability may contribute to knee and foot injuries through abnormal tibial rotation.