What are the SITS muscles of the rotator cuff?

The SITS muscles are the four scapulohumeral muscles that make up the rotator cuff: Supraspinatus, Infraspinatus, Teres Minor, and Subscapularis. They form a musculotendinous cuff around the shoulder joint.

What is the main function of the rotator cuff?

The primary role is dynamic stabilization of the shoulder during movement, especially preventing upward displacement of the humeral head within the glenoid cavity.

What is a common clinical issue related to the rotator cuff?

Rotator cuff injuries are common, often affecting the supraspinatus tendon. This can lead to impaired arm abduction, particularly from 0° to 15°, and may involve compensatory trunk movement.

How does the scapula move during shoulder function?

The scapula glides on the posterior chest wall with loose connective tissue, involving movements like protraction, retraction, elevation, and depression. All scapular movements involve motion at the sternoclavicular and acromioclavicular joints.

Why is lateral rotation of the scapula important?

Lateral rotation of the scapula is essential for arm abduction beyond 90°. Paralysis of muscles like the serratus anterior or trapezius can severely limit this motion, affecting tasks such as reaching overhead.

Which muscles are involved in scapular protraction and retraction?

Protraction is mainly performed by the serratus anterior, assisted by the pectoralis minor. Retraction involves the middle fibers of the trapezius and the rhomboids.

Rotator Cuff Anatomy – SITS Muscles & Clinical Notes