Management of position, posture and weight distribution are key elements to skiing. In the “pattern”, our weight is over the right leg driven in part by a dominate right antero-lateral abdominal wall. This works in our favor with a left turn. The pelvis is oriented to the right, we have Right AFIR, right shoulder is down with left trunk rotation and a right arm forward.
Weight distribution over the right ski, or downhill ski, in a left turn is pretty important especially with the ability to adduct and internally rotate on the right. The inside portion of the ski, or the inside edge, is necessary so that we don’t slide or fall straight down the hill. This is called edge control and the ability to evert the downhill ski while we invert the uphill ski gives us direction and control. This is also called a parallel turn.
The ankles in a ski boot are fixed and move very little so frontal plane control has got to come from the hips and knees. But the feet and ankles have an important role with sensing the ground and signaling the brain and rest of the kinetic chain the position of the skis and helping to control shifting of weight side to side, forward and backwards.
Tri-planer thinking starts with sagittal plane and having a neutral pelvis is necessary to transfer load from right to left side, left turn to right turn. Without sagittal plane control and maintaining it, frontal plane control will suffer since adducting a femur then internally rotating it will be limited at best. Without sagittal and frontal plane management, a ZOA on the left will also be compromised and limit the ability to turn a pelvis to the left to stay effectively in left stance with right trunk counter rotation. As a side note, this directional separation of pelvis and rib cage is another critical component to performance. Trying to teach someone to just “get better” at right turns without a tri-planer position awareness will be a limiting factor at best.