Never heard of functional tension josseph?
I don't have much time to hit on it now, but it has been and idea that is key in high level disciplined skiing. I'd recommend checking out the article in last months "The Professional skier" on it. If you're not an instructor and don't get that mag, I will see if I can post it. It is definitely the key to allowing your absorbtion to come from the lower body instead of the waist. without discpline of the upper body and a strong core, bumps and crud can both be very irritating exercises and tough on the lower back.
the bottom line, find the correct balance of tension between two opposing muscle groups. in the illustration I've made above, you need the tension between the abs and lower back. for good footwork and accurate ski control of both feet, you need a balanced tension between the shin muscles (anterior tibalis) and the calf muscles. another key to a strong POS (postion of strength) is the functional tension between the hamstrings and quads.
Functional tension doesn't mean tight, though. we need to loose enough to respond and fire the muscles quickly, but strong enough that we don't get thrown out of our POS.
there has been an awful lot of talk here around the active dorsiflexion of the inside foot in a turn. That is another illustration of funtional tension. If you relax it too much, the inside ski slides forward and tends not to stay on matching edge angles with the outside.
Anyway, got to run. I hope that helps.