Knee valgus vs. knee abduction angle: comparative analysis of medial knee collapse definitions in female athletes

Many methods are used to quantify knee valgus angle (KVA). However, not all angles used to calculate KVA are equivalent. Four methods of calculating KVA were used on twenty-three athletes during a drop jump using a 10-camera motion capture system. The results showed that using a global reference frame in two and three dimensions as well as using the pelvis as a reference frame may produce equivalent angles. However, this study showed that values calculated using body fixed coordinate systems did not relate to the global or pelvis reference frame.