Answer
The rotator cuff is a structure that is formed by the tendons of the following shoulder muscles: subscapularis, supraspinatus, infraspinatus and teres minor. The rotator cuff strengthens and stabilizes the very flexible and relatively vulnerable shoulder joint.
All the tendons of the rotator cuff may be injured, but the tendon of the subscapularis is the one most often damaged.
Work Step by Step
Difficulty in making certain movements can be related to damage of certain tendons in the following way:
1. Damage to tendon of subscapularis
Difficulty in medial rotation of arm
2.Damage to tendon of supraspinatus
Difficulty in abducting arm
3. Injury of infraspinatus and teres minor
Difficult lateral rotation of arm
4. Injury of Teres minor
Difficulty extending arm
The rotator cuff is seriously stretched during pitching for a baseball game. In the winding-up process the distal end of the baseball pitcher's arm makes a circle , while the proximal end remains fixed. This motion is called circumduction, and it is the reason why so many baseball pitchers sustain rotator cuff injuries.
It is surprising that Jose's high school baseball coach did not warn him that rotator cuff injuries are the most frequent injuries of baseball pitchers.
