I took a 35 mile hike about a week and a half ago. 5 miles or so in, I pulled "something" in the back of my leg behind my knee. after two more days on the trail, and coming home and resting, the inside of my knee, on the lower left part of my kneecap started to hurt pretty badly. It never swelled up or anything like often happens when people tear ACLs or something of the like, but has anyone here had a similar experience? It usually hurts when some pressure pulls the bottom of my leg away from my body, but it doesn't take much. For the most part I can walk, run, and everything if I had to, but I'm a bit concerned.