I will take vids when I eventually get back onto the courts and post here to see if my serve/tennis technique is the cause of all this or if it the result of improper lifting technique when I started weights. Actually I did used to have a single handed backhand and did have a some impingement issues about a year into tennis. This is about 2 years ago...
I did take a vid when I was developing my serve and from memory its pretty much what Pat Dougherty and Todd Ellenbecker recommend. However I dont have quite the knee bend or shoulder angle they recommend.
Again when i'm back on the courts i'll post vids up for critique.