Yeah, and I know that from experience. A few years ago I messed up my left rotating cuff really bad by overdoing elevation exercise without warming up enough, after being sedentary for months and really thin, without any muscle mass in the arms. I developed acute tendinitis and bursitis that made unbearable for me to twist my arm or resist any downwards force while arm was streteched sideways.I'm not expert, either, but I know most muscle injuries are associated with poor warming up routine or being inactive for long stretches and then a sudden overload.