Spinatus muscle

Spinatus Muscles

Illustration of the Spinatus Muscles from Gray's Anatomy

The Spinatus Muscles are a group of muscles located in the shoulder region. They are primarily responsible for the rotation of the arm and play a crucial role in the stability of the shoulder joint. The group consists of two muscles: the Infraspinatus and the Supraspinatus.

Anatomy

Infraspinatus Muscle

Infraspinatus muscle

The Infraspinatus is a thick triangular muscle, which occupies the majority of the infraspinatous fossa. It originates from the infraspinous fossa of the scapula and inserts into the greater tubercle of the humerus. Its primary function is to laterally rotate the arm and stabilize the shoulder joint.

Supraspinatus Muscle

Supraspinatus muscle

The Supraspinatus is a relatively small muscle of the upper back that sits just above the spine of the scapula. It originates from the supraspinous fossa of the scapula and inserts into the greater tubercle of the humerus. Its primary function is to assist in the abduction of the arm and stabilize the shoulder joint.

Clinical Significance

Injuries to the Spinatus muscles, particularly the rotator cuff tear, are common in athletes and individuals who perform repetitive overhead activities. Symptoms may include pain, weakness, and loss of range of motion in the shoulder. Treatment options include physical therapy, medication, and in severe cases, surgery.

See Also

• Rotator cuff
• Shoulder joint
• Musculoskeletal system