Howdy, Lately I've been working on taking my serve up a notch in the power department. Mainly focusing on keeping my 90 degree knee bends at trophy position. However, after an hour of practicing, my vastus intermedius (or simply lower inner thigh muscles) hurts like ****. Is this normal? Besides, I find great difficulty in trying to maintain my balance when I slide my hips forward to mimick an archer's bow. I either keep falling backwards or forwards. Am I in need to lose some of my upper body heft? LOL... It will be great to hear your experiences, especially those with a platform stance.