I've been playing tennis for about 5 yrs now. It seems as I've gotten better and increased my swing speed my rotator cuff is always sore after a match or hitting session. It gets sore from groundstrokes and not the serve. Is this normal? Most people I talk to don't think so. It's really annoying to get a really sore arm the day after I play. I have been doing rotator cuff exercises pretty regularly, but the muscle soreness persists. Any advice?