Usually about 5-6 times a week, I will stand up from sitting down and I immediately get a sharp pain in the front of my upper thigh, about 3 inches below my waist. It is painful to put any pressure on it, but goes away after a minute or two. I usually have to limp it off in about 5 or 6 light steps. Does anyone have any ideas what may be causing this? I do not play sports or exercise too often, but I am in pretty good shape. Thanks.