I was coming down gliding out of some steep trees back out onto the well packed skin track and when I did, the tip of my left ski caught on the edge and pretty much turned my entire left leg outward almost 180 degrees. It hurt, but I didn't realize I was really injured until after I'd sat in the truck for over half an hour driving home. By the time I got home it was swollen up a good 50% larger than normal and was getting pretty darn stiff. I went and got it checked out and was relieved to find that it was a grade 2 MCL sprain, but no meniscus or other damage. I was back riding in two weeks and pretty much good as new after a month.