Ok, I'm going through exactly this right now. Try something clint, get in a chair with some rollers, or one of those stools that moves around on some balls at the bottom. Using only the leg in question, try and pull yourself accross the room by digging your heal into the carpet and pulling, using your hamstring. What does that feel like? Those hamstring tendons come right around on the medial side of your knee and connect on your shin. After my ACL reconstruction, mine burned. I have some slight tendonitis, which is what I think you have, and ice is totally the answer. Ice the crap out of it and try doing some healslides (lay on the bed and dig your heel into the bed, while sliding your heel toward your butt. If that bothers you at all, either the heel slides or the chair exercise I described, then Ice it down and just lay off of if for awhile.