Hi, i was playing basktebal and wehn the girl landed on me my back of my leg started to hurt. The paint went away the next day but is now back. It is located behind my leg below the wasit. It feels like it is bruised. I can walk but cant run because i feel like pain. Also, when i sit down it hurts. I no its not a burise because it doesnt show. My coach is concern that i might have done something called pulling my hamsting. I need to know if this is correct and what to do to help it.