Infraspinatus muscle

The infraspinatus muscle (Latin for " Untergrätenmuskel " ) is one of the shoulder muscles of the upper arm. He is partially obscured by the deltoid muscle. Together with the supraspinatus, the musculus teres minor and the subscapularis muscle it forms in humans, the rotator cuff, which keeps the head of the humerus in the glenoid fossa.

Function

The infraspinatus muscle is responsible for abduction and adduction. The main task consists in the external rotation of the arm.

In the four-footed mammals in the shoulder joint mobility is significantly restricted to the outside, so that only flexion and extension are possible. In addition to the diffraction in the shoulder joint of the musculus infraspinatus acts as an elastic side band and prevents the lateral deflection of the shoulder joint.

• Skeletal muscle of the upper limb