subcapsularis

The subscapularis muscle is one of the four muscles that make up the rotator cuff, a group of muscles and tendons that surround the shoulder joint. It is located on the anterior (front) side of the scapula (shoulder blade) and inserts onto the lesser tubercle of the humerus (upper arm bone). The subscapularis is the largest and strongest of the rotator cuff muscles.

The primary function of the subscapularis is to internally rotate the arm. It also plays a crucial role in stabilizing the shoulder joint by adducting the arm and helping to depress the humeral head. This muscle works in conjunction with the supraspinatus, infraspinatus, and teres minor muscles to provide dynamic stability and allow for a wide range of motion in the shoulder.

Injuries to the subscapularis muscle, such as tears or strains, can significantly impair shoulder function, leading to pain, weakness, and difficulty with movements that involve internal rotation and lifting the arm. These injuries can occur due to overuse, trauma, or as a result of degenerative changes. Rehabilitation often involves physical therapy to strengthen the muscle and improve range of motion.