The best thread I have read is this one regarding tennis elbow:
Light racquets are death on the elbow. I can not stress enough what others have said. Heavy, but head light balance is a huge factor. You can find my reply to in that thread where my wife was suffering very badly. She could not reach into our cupboards to get things without wincing. I took her head heavy Wilson Hammer and sold it on **** and bought a Prince O3 White. Within days, she was better and has been pain free for 18 months or so.