GLOSSARY

The rotator cuff muscles are four muscles arising from the scapula whose tendons grip the head of the humerus like a cuff and stabilise the shoulder joint.

Members (SITS)

• Supraspinatus: initial abduction.
• Infraspinatus: external rotation.
• Teres minor: external rotation.
• Subscapularis: internal rotation; the only anterior muscle.

Main Function

• Centring the humeral head: holding the humeral head in the shallow glenoid fossa, like a golf ball on a tee.
• Counteracting the upward pull of the deltoid.
• Rotation of the arm.

Relevance to Sport and Clinical Application