The shoulder is a complex joint–what does the research say is the weakest rotator cuff muscle and why?
My vote is split between the teres major and infraspinatus even though the supraspinatus is the one that usually gets beaten up. The muscles for external rotation are always weaker than the ones for internal rotation but all of them together cooperate in keeping the head of the humerus in the glenoid fossa.
I am curious about your answer.
Karin Singleton
www.meltnc.com
