I am having a problem with my girlfriend when she hits her forehands. Her left hand stays close to her body at all times (like its glued) I want her to extend her arm out but Im not entirely sure how to tell her. She wants me to give her reasons why. apparently "because all the pros do it" isnt a good enough reason for her...haha...In any case, does it have to do with her balance when hitting a shot? Maybe even giving her more power and control? If so, i need evidence i guess... Please advise! I want her to hit better groundstrokes with more pace and control!