|Hi, there. I wanted to ask anyone who has pulled there hamstring to help me out here. In 1997, I was 14 and running track in gym class at school when I pulled something at the back of my upper leg, went to the DR did ultrasounds, took a cream for it cause he has said it was an infection. Then in 2003, after a 2 hour walk I pulled it again, the DR said it might me Lipoma, a fatty benign tissue that occurs in some people. He gave me pills for it etc... Two weeks ago almost, I pulled it again, but during Aerobics class at the gym, it was a step class a very vigourous one. I don't really think it's anything that bad. But I am booked for an Ultrasound next Thursday. My DR, seems to be a total clueless, person. Because he can't rule out what it is. I have two lumps they feel like knots in the back of my upper left leg. It feels like a burning stabbing sensation. As if I pulled or torn and ruptured a muscle. Can anyone tell me if that sounds like a severe hamstring injury, because it only happens after vigorous excercise sometimes, besides that it doesn't give me problems. So, next week UltraSound, then he said I am possibly going to a Muscle Specialist, cause the Lipoma he thought it was is supposed to be soft, and this is tender, as if it's a pulled muscle!! Help!