EE WAS APPLYING FORCE TO A COMEALONG HOLDING A PIPE THAT HAD MOVED AFTER THE BOLTS WHERE REMOVED FROM A FLANGE. THIS PIPE HAD MOVED MORE & IN A DIFFERENT DIRECTION THAN PLANNED. EE PERFORMED T ASK WITH LESS THAN DESIRABLE THOUGHT FOR BODY POSITION & EXERTION, RESULTING IN MUSCLE STRAIN. EE WAS PLACED ON RESTRICTED DUTY ON 6/4 & X-RAYS WERE ORDERED.