Muscles of the Shoulder

muscles of the shoulder

There are several different muscles that make up the shoulder. Among these muscles are the rotator cuff, Pectoralis minor, Infraspinatus, and Supraspinatus. These muscles provide a wide range of motion. Several ligaments and cartilage surround these joints, which give the shoulder its stability and motion. The clavicle attaches the arm to the chest and connects the shoulder to the neck.

rotator cuff

The four muscles and the tendons attached to them form the rotator cuff. These muscles work together to support the upper arm in the shoulder socket, and they help in a specific range of shoulder motion. The four rotator cuff muscles originate from the shoulder blade and attach to different parts of the upper arm bone. The largest rotator cuff muscle, the supraspinatus, helps move the shoulder away from the center of the body and produces the first fifteen degrees of abduction. The two smaller muscles, the infraspinatus and deltoid, take over the remaining 15 degrees of abduction.

Pectoralis minor

The measurement of the pectoralis minor muscles of the shoulder may suggest a potential imbalance between these muscles. However, there is no scientific proof to support the hypothesis that shorter pectoralis minor muscles are associated with lower shoulder pain. The study’s authors recommend normalizing the length of the pectoralis minor muscles. These results are promising and warrant further research. Here are some things to keep in mind before you take the measurement.

Supraspinatus

The Supraspinatus is one of four muscles in the rotator cuff of the shoulder. It attaches to the upper portion of the scapula and the greater tubercle of the humerus. It helps the deltoid initiate abduction of the arm and stabilizes the shoulder by drawing the humerus towards the glenoid fossa on the scapula. The muscles are innervated by the suprascapular nerve, which comes from the upper trunk of the brachial plexus. The suprascapular nerve runs to the shoulder and is often damaged by fractures of the overlying clavicle.

Infraspinatus

The infraspinatus is one of four muscles that make up the rotator cuff, which help stabilize and move the shoulder joint. It also assists in the direction of the humeral head during upper extremity movements. Located on the dorsal surface of the scapula, the infraspinatus muscle originates from the medial two-thirds of the infraspinous fossa. Its fibers arise from the infraspinatus fossa, which is a thick, fibrous navicular artery surrounding the infraspinatus muscle. It attaches to the posterior aspect of the greater tuberosity and assists with external rotation of the shoulder.

Subscapularis

To diagnose a subscapularis tear, your physician will ask you about your medical history and perform a physical exam. He will also perform physical tests, such as the bear hug or lift off test, and will likely order an MRI or ultrasound to confirm the diagnosis. A subscapularis tear can result from an injury to the underlying muscles or the shoulder’s tendons. Here are some symptoms that might be indicative of a tear:

Latissimus dorsi

The latissimus dorsi is one of the prime movers in the motion of transverse extension. In rowing, it is responsible for controlling the shoulder blades’ bottom portion. The other shoulder muscles, such as the anterior deltoid, are antagonists. Therefore, it is important to exercise these muscles in order to enhance their action. In general, you should aim to develop a balanced range of motion by exercising these muscles.

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