This has happened to me a number of times, both while serving and while hitting a forehand. I'm 21 and in decent shape, play about 5 times a week. A while ago I'm playing and a ball's coming fast to my right - not sure if I'll be able to make it to it, but I'll try - it's an important point; so I reeeallly reach out and really stretch for it to hit a forehand. Sharp pain in my rotator cuff/shoulder area, not a tear or a pop sensation, just a stabbing sharp pain, like I over-extended it beyond capacity. So I stop. When I get home, hurts to move it. Took about 2 weeks to heal before I could play again. So about 4 weeks I'm playing fine, then I do a bad serve toss, throw the ball too far into the court. Instead of letting it bounce, I reach forward and try to hit it (a mistake), and I get the same sharp pain in the rotator cuff I did for the forehand, almost identical. Again, hurts in the shoulder area to move it, so I'm out again for 2 weeks. Basically I'm wondering what type of injury this is, what I can do to prevent it. I guess all I can do is be mindful of overextending my arm, and try not to hit bad tosses, and try to not do wild stretches without first pushing off with my feet? This is basically the only major injury I've had in tennis but it's happened at least 3 times now in the past year, and it's always from my arm way too far out and swinging... Suggestions/analysis of the injury? Thanks!