Rotator cuff
Mm. supraspinatus, infraspinatus, teres minor, subscapularis
// Structure & location
The cuff consists of four muscles that all arise from the shoulder blade: the supraspinatus on top, the infraspinatus and teres minor at the back and the subscapularis at the front. Their tendons blend with the joint capsule and insert on the tubercles at the top of the humerus.
// Function
According to OpenStax, the muscles and tendons of the rotator cuff provide stability to the shoulder joint. They pull the head of the humerus into the socket while big muscles like the deltoid and pecs move the arm. They also rotate the arm outward (infraspinatus, teres minor) and inward (subscapularis) and help lift it to the side (supraspinatus).
// For training & sport
- External rotation with a band or cable, elbow at your side, trains infraspinatus and teres minor.
- Face pulls combine external rotation with shoulder blade work.
- Pain when lifting the arm to the side often involves the supraspinatus tendon.
// Good to know
The supraspinatus tendon passes through a narrow space under the roof of the shoulder. If it gets too tight there, it's called impingement. Tears in this tendon become more common with age, often without any symptoms.
// Sources
- LehrbuchOpenStax – Anatomy and Physiology, 11.5 Muscles of the Pectoral Girdle and Upper Limbs ↗
- LehrbuchOpenStax – Anatomy and Physiology 2e, 9.6 Anatomy of Selected Synovial Joints ↗