Back knee hurting during compressed toe-side carves?
A few weeks ago I learned the basics of carving (based on posts here and on other websites) but knew I wasn't going fast enough or tight enough, and knew I wasn't getting my body compressed enough. Yesterday I had my carving epiphany where I was going faster, tighter, and super compressed into the board, cutting real deep lines I could easily pick out from the lift. On my toeside carves my back knee was practically scraping the snow I was so low, I had to push it forward even more to keep it clear... and I could easily rest my entire back forearm on the snow. And going ever so slightly airborne while unloading and changing edges... what a cool feeling... happened instinctively, despite having read about it before.
So obviously stoked about the carving. Here's the problem. I did hard back to back carves down a mellow slope for about two hours just trying to perfect it, until my back knee started hurting pretty bad, but only during the toe-side carves. I think it has something to do with driving it forward and also putting a torque on it trying to flex/turn the board tighter, and crouching super low. I could still do okay carves standing up straighter (on smoother runs) with no knee pain... but of course it's more fun to get real low.
Any ideas, anybody else experience this and have any tips on minimizing it? Thanks!
EDIT: One thing I thought of, my back foot is at zero degrees and I'll bet if I angled it forward some that might help a bit... at the cost of what little switch ability I have.