Repetitive strains can happen to any part of the body. RSI is commonly used to describe pain in the hand or arm from typing, but you can get RSI in the shoulder if you use one arm above your head repeatedly during the day. Perhaps you’re a javelin thrower or you do rock and roll dancing, both of which involve repetitive shoulder movements.
There’s no single cause of RSI, it is just repeated use of the area that generally causes inflammation of the tendons or tendon sheaths.
Treatment usually involves the use of ice and taping or strapping to prevent over use.