Yesterday, after several days of terrible back pain, I saw a chiropractor who discovered that I had a dislocated rib. When he 'popped' it back in place, most of the horrible pain went away immediately. The most likely cause of the injury was tennis. One day I was by myself, so I practiced serves and overheads for an hour. (To do overheads alone, use your racquet to send the ball way into the air, let it bounce, and then smash). I hadn't been playing tennis lately, because here in Arizona it just seemed too hot. So the combination of not playing, and then practicing too long caused me to dislocate a rib. I'm still recovering, but I'm wondering if I'll ever want to risk playing tennis again. I don't ever want to go thru an ordeal like that again! Has anyone else ever had back trouble from tennis.