I am a 4.5 player on a good day and as I creep into my mid thirties I am noticing a few aches and pains that had never been there before. Most notibly my arm sucks! I can hit groudstrokes just fine, but when I get to my serve, my triceps and elbow start to throw in the towel. I have been using Speed MP 18x20's. I really like them, but the pain is no fun. Are there any suggestions for a racquet change? Serving is important to me, I have a booming first serve and a kicking second serve. I don't want to lose any weapons.