I recently started playing with a PK Ki 315. Although it helped, I'm getting a good amount of pain starting to creep back in my shoulder and arm. I even have Softflex strings at low tension (53 lbs.) Also, this racquet may be a little on the heavy side for me, could that be contributing to pain? I hit about 3 times a week. The serve seems to be what causes the most discomfort. Any advice or alternate racquet suggestions would be appreciated. I'm not sure what my rating is, but I would consider myself an intermediate rec player. Thanks again.