Originally Posted by SoftSnowGuy
First, how about some simple definitions--
Down unweighting is identified when the outside knee bends to release the ski. Up unweighting happens when the outside knee straightens to release the ski. It doesn't matter if the center of mass goes up on either...and it usually does go up on both types of releases. Down unweighting is an old term. The modern term is a retraction turn. If there is an obstacle, like a mogul, the same movement is called an absorption turn.
Retraction turns are always quicker than extension turns. This was clearly documented at the 1996 International Congress on Science and Skiing. No racer who knows better will do an extension turn unless there is a tactical reason to do one.
That instructor didn't know what she was talking about. In a well done retraction turn, the forces that build through the turn are handled by putting the ski more on edge (with more body angulation) toward the bottom of the turn. The outside knee is held nearly straight unless it is needed to bend just a bit at very high force levels. When the outside knee bends quickly and releases (actually just relaxes), and the torso muscles that held the angulation also release (relax), the force of gravity and centrifugal force, plus the spring of the skis, plus the relaxed torso muscles that had been stretched (opposite the muscles that were contracted) fling the skier across the skis. In an extension turn, the forces are dissipated into the leg muscles as the skier flexes their ankles, knees, and hips toward the end of the turn, then the skier pushes hard against the snow, rises straight, and twists their skis around.
The ski instructor organizations, being 99 & 44/100ths percent dedicated to steering the skis in every turn, need the extended body to turn the skis into the new turn. You can't steer from a crouch.
So, continue the retraction turns. Enjoy the forces that throw you across the skis and put you on edge for the next turn. If you get the timing right, you'll show the bases of your skis to the skiers uphill from you and carve around the next turn so sweetly.... Retraction turns are also much easier on my creaky knees than extension turns. Make an extension turn any time it feels good to fly over the snow or when you need to jump over an obstacle.
WOW! I sure hope your knowledge is more in depth than what you wrote here! If you truly believe that its all about name differences, you obviously have no idea the true function and mechanics of the down unweighting turn, the retraction turn, and the flexion turn! I mean, c'mon- this is basic stuff! About as fundamental as it gets!
To define these turns, you need to ascertain the energy source (internal vs external), whether the movement is active vs passive, and the direction of the energy and movement...
In a down unweighting movement
, the source is INTERNAL, ACTIVELY using MUSCLES to abruptly move the CORE TOWARD THE FEET. This results in a very short duration reduction of pressure between the skis and snow, as the effectis only as long as the duration of the rnage of movement. Timing of this movement is critical, due to its short effective duration
In a retraction turn
, again the source is INTERNAL,ACTIVELY using MUSCLES to aggressively pull the FEET TOWARD THE CORE. Though the duration of the effect can be a little longer than down unweighting, it still is of relatively short duration. A significant difference between a retraction turn and down unweighting is that a retraction movement can be done effectively just about any time and in most environments, whereas a down unweighting movement has more limited effective use. A retraction turn also offers greater control than down unweighting, but not even close to the degree of precision offered by a flexion turn.
In a flexion turn
, the source of energy is EXTERNAL, using the energy developing in the skis (ANGULAR MOMENTUM and GRAVITY) as they arc/carve through a turn. The skier then PASSIVELY allows the legs to flex (FEET TOWARD CORE) as much as necessary to manage the external energy at a degree which is functional. This allows the skier to very precisely determine how much energy is desired to affect the turn and the ensuing transition. Conversely, the skier is then capable of extending the legs (FEET AWAY FROM CORE) with a degree of precision necessary to maintain the desired pressure between the ski and snow in the top half of the turn.
It truly baffles me how many good skiers do not understand the differences between the retraction and flexion turns, yet are capable of doing both. But the misrepresentation of which is which totally negates the foundation which any discussion of these movements must be founded upon.