Last week I changed strings on my raquet from babolat xcel to duraflex due to arm problems. with babolat xcel i never had problems hitting forehands because i used to hit topspin forehands. now with duraflex i am having such a hard time hitting topspin forehands nor can i hit flat forehands. i am totally out of confidence. what can i do? i do not want to go back to old babolat strings because of the arm issues. how can i hit flat forehands?