To who would you attribute this?
Originally Posted by mystery skier
Lateral knee actions are not just limited in the human body, they can't occur unless you want torn medial or lateral collateral ligaments!!. The knee is a hinge joint and it bends or flexes the leg in the Sagittal plane (viewing the body from the side). Any significant perceived lateral moments, the ones noticed in skiing are viewed mostly on the frontal plane (viewing the body from the front).
When we see the knee moving in the Frontal plane it is not the knee joint flexing that creates the medial or lateral appearance of knee movement, it is the rotation of the femur in the hip socket that creates the perception that the knee moves in or out. Femur rotation has to be initiated by ski tipping or ski skidding is the result, especially in less proficient skiers.