Breaking Myths
Many have asked, ?Is this a trick question?. Its not a trick question, it?s a probe into what people think about skiing movements, how they describe them and how they understand them.
Before we get into the details we have to understand the biomechanics of knee capabilities, possibilities, perception of knee position in static and dynamic situations.
Can we break myths and perceptions surrounding the perceived actions of the legs in tipping, steering and rotary movements? In addition, can we relate the knee and leg movements, which are the biomechanics of skiing, to ?applied skiing?, on hill skiing situations?
I hope this discussion brings skiers and teachers to a new level of understanding, and the beginning of a new era of clarity in skiing understanding. In the development of PMTS from inception, we have long worked from these levels, but I have failed, as yet, to entice and communicate to instructors what the real biomechanics of skiing are. I think I have accomplished more with skiers, then instructors. I won?t go into the reasons, but there are many explanations for why understanding of skiing biomechanics hasn?t advanced.
Knee movements
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.
The perception of knee movement is what skiers refer to when they talk about knee angulation and knee movement. The knee is a reference point; it does not have lateral movement capability.
Lateral ski and boot movements, specifically tipping, begins at the base of the kinetic chain with muscles in the lower leg, at the ankle and foot.
Kinetic chain power
Higher up the kinetic chain muscles surrounding the pelvis and on the medial side of the femur, the adductors, are recruited to support foot and ankle movements. There are no muscles that move the knee in or out, or side to side.
If we want to discuss skiing accurately, which would offer skiers specific relationships to actual movements; we should focus on the movement capabilities of the body, rather than the reference points.
I described in another recent post the reasons for using the base of the chain for movements.
http://www.realskiers.com/pmtsforum/vie ... php?t=1065
How should understanding of body movement origins and capability influence how we teach, and how we move to attain the skiing goals we prefer?