I think I have pulled or torn a muscle in my upper right arm. Ice an heat have helped but cant find a comfortable way to be able to sleep. It is better during day.....but hurt if I move it much. Can t put any weight on it. Hurts to move arm out or forward. Is it best to immobilize it or move it gently. The injury occurred after water aerobic class where we did a lot of arm work. it has been 1 week since pain started.