Most skiers get told one time or another by a coach that there is too much upper body or hip rotation in their skiing. This usually gives the skier a weaker edge support in the turn and poor body positioning over the skis. The result – A vulnerable and weaker set up for overall dynamic balance. Upper body or hip rotation is usually more apparent in one direction. Steering needs to come from the legs with the balls of the femur rotating inside the socket joint of the hips so that we can avoid twisting in the spine or at the knees. This allows the legs to steer past the fall line without the hips and upper body interfering.
In most cases skiers can step their feet around approximately 35 to 45 degrees across either side from the fall line. This means that when they steer from turn to turn and the steering of the skis is greater than say 35 or 45 degrees, the upper body will start to rotate.