I've been reading threads here and there and jumping in when I could. Even re read some older threads and specifically, VSP's "Where do we want our hips thread http://www.epicski.com/t/90579/where-do-we-want-our-hips-over-our-feet-why-do-we-want-to-move-our-hips-forward. I didn't reread all 7 pages, but enough to be dangerous. After doing that, pondering other things I've read then going out and cut the grass (great time to think about skiing), my thoughts started going back to an incredibly informative, albeit dry paper I read about skiing a few years back;"FINITE ELEMENT SIMULATION OF A CARVING SNOW SKI" by PETER ANDREAS FEDEROLF, http://e-collection.library.ethz.ch/eserv/eth:28070/eth-28070-02.pdf 143 pages of "what the heck is happening when you're carving?"
I've posted links to it now and again and so have others. I admit, I read the words and looked at the pictures. I didn't verify his math or even pay attention to it (there's a LOT of math). I haven't re-read the paper in a couple years and don't really want to, though I probably should. Just don't have that type of time right now. What I gleaned from it was the body moves around quite a bit; fore and aft, laterally, and up and down. The surface of the ski that sees the most action is primarily underfoot to the tail. The tip is involved, but is more subtle (not sure that is the right word as it is so significant to turning). The pic below is from the FESOACSS paper. One of the reasons I think there is more action at the tail, is because the ski keeps digging in further as it goes, so the tail has more surface contact the snow then the tip did.
Why do I bring this up? Well it occurred to me while cutting the grass, it isn't about us and where we are while carving. It's about the ski. We drive the ski. The ski does what we tell it, but it only listens to certain commands. If you don't tell it exactly what to do at precisely the right time, it will do what it thinks you want it to. Coincidentally, I think about things like this a lot while cutting the grass. Not just because I love skiing, but because my yard isn't very flat and I have areas with double fall lines and when you use a riding mower, you have to think about where your body is while turning so you don't flip it over or skid into my wife's Rigosas (again!).
How I make a turn on my riding lawn mower depends on a couple things; which rider am I on (I have an older craftsman and a zero turn radius craftsman), where am I in the yard (slope, flat or double slope) and sometimes whether I care about what it does to the yard (the ZTR can tear up the sod). The laws of physics apply. Some places I'll skid a turn if going too fast and others I won't, even if going faster.
Both of the tractors are machines. They do what you tell them. Skis are machines too, gravity is the motor and we drive. Again, they do what we tell them.
So I really think that which set of skis I'm on, and probably more importantly what terrain I'm on, will dictate where I and my hips need to be when, while skiing. Look at where the contact is on Lindsey's outside ski. Look at the picture above showing pressure distribution. I would say she is balanced in reference to the terrain and the forces being applied to the skis. On flatter terrain, she might be more forward but would be going slower.
Maybe it isn't about where the hips are, but what the ski needs. We've all been walking and all of a sudden changed our balance point because something happened, like realizing we're taking a corner too close and don't want to bump it. Maybe someone comes out of a doorway and we twist a little so we don't bump into them. Walk across a flat area with flat shoes then down hill with flat shoes. Do it again and turn part way through. Now put on something with more of a heel. For me it's logging boots ( hate that heel). Boy do my knees feel it. I walk differently going down hill in loggers than loggers in the flats or down hill with flats on. Now do it all over again but run. I have to adjust my body because the slope, ankle flex and speed all changed.
Anyway. That's how it works in my head.
Edited by L&AirC - 8/2/14 at 5:03am