Supraspinatus
This small muscle acts to hold the head of the humerus in the glenoid fossa, especially in the follow-through of throwing movements.
• This muscle also assists the middle deltoid in raising the arm to the side.
• And, because it inserts on the top rear of the greater tubercle, it also rotates the arm outward.
ORIGIN:
Supraspinous fossa.INSERTION:
Top of greater tubercle of humerus.ACTION:
Weak, shoulder joint abduction. (External rotation of the shoulder joint.)example exercise