Originally Posted by BigE
Because the mechanics are contradictory.
Kind of like adding outside leg relaxation to retraction.
BigE, I don't think this is really true in my opinion. The mechanics are not opposite, they are really a matter of degree of intramusclature recruitment and a matter of reversing the roles between the agonist and antagonist. Something we do all the time in our movements. To relax a leg we simply reduce the amount of recruited fibres so the outside force is greater than the muscle contraction force. These movements are always balanced by the opposing muscle in the pair. In other words, at every joint we have groups of muscle that control movement. they work synergisticly to control movement, and/or stabilize the joint. If we have joint movement it is really very easy to go from relaxing to retracting because it involves the muscles already activated, and only requires a change in the amount of effort in the respective muscles, and not a change in direction. Further, changing the amount of recruited effort changes the role of the respective synergists, but within a given joint action it will always be the same group of synergists making things happen.
Here is some food for thought about tipping (ab/adduction) versus steering (rotation). While it is true that rotation with a straight leg is a weaker movement, as we flex the lower joints we increase the amount strength available from our muscles. Interesting to me is how many of the same muscles used for rotation are also used for ab/adduction. And even more interesting to me is how ab/adduction creates rotation as we deepen our flex in the lower joints. In my mind this is attributed to how the angle of pull changes as the hip flexes. HH even discusses this briefly in his book as he talks about how the knees move as we tip our feet when we have flex in our lower joints.
So the gray area lives in how we choose to think about, and apply these movements in our skiing and not really how the body is moving or what muscles are involved. Really the only thing that may seem contradictory is what we intend to do, so in my book they do blend very effectively together. Whether it is relaxing versus retracting or steering versus tipping. So I say yes, we can fluidly move between relaxing and retracting as we can also move between steering and tipping.
The hips are such awesome joints, as they move in all three planes at once. Because of this we can add or subtract the effort being put out in any of the synergistic muscles involved in the hip actions and in so doing change the outcome on the fly. I don't see these movements as black or white but more on a sliding scale. How else do you get a skidded turn from tipping (Ricks question), or that little pivot entry you see in many of the PMTS demo's.
Personally I don't buy into the idea that we can't learn to control any of our natural joint movements if we apply ourselves.
I'd like to hear some thoughts on this.