Final answer:
The rotator cuff is composed of tendons from four muscles around the shoulder joint and is crucial for shoulder movement and stability. It is susceptible to injuries, particularly from repetitive motions like pitching in baseball, which can cause inflammation, pinching, or tearing of the tendons.
Step-by-step explanation:
The rotator cuff is a musculotendinous cuff that encompasses the shoulder joint, composed of tendons from the subscapularis, supraspinatus, infraspinatus, and teres minor muscles. This structure is fundamental in shoulder movement and stability, especially in activities that involve lifting the arm overhead, as seen in baseball pitchers who frequently suffer from rotator cuff injuries.
Rotator cuff injuries are prevalent in sports that require repetitive overhead motion and might necessitate surgical intervention to repair. These tendons attach the scapula to the humerus and enable a range of motions for the shoulder joint including rotating and lifting the arm. The deep posterior compartment of the arm and other surrounding structures contribute to these movements and overall shoulder health.