Overview
A thick muscle that fills the supraspinous fossa and bulges beyond the cranial border of the scapula. Together with the infraspinatus it acts as a contractile ligament stabilising the shoulder joint. In cattle it ends in two branches, one on each side of the biceps brachii tendon.
Origin
Supraspinous fossa (fossa supraspinata) and spine of the scapula.
Insertion
Cranial parts of the greater tubercle (tuberculum majus) and the lesser tubercle (tuberculum minus) of the humerus.
Action
Extends and stabilises the shoulder.
Innervation
Suprascapular nerve (n. suprascapularis).
Clinical relevance
- Suprascapular nerve injury causes atrophy of the supraspinatus and infraspinatus, leaving the spine of the scapula very prominent.
- Cranial to its border, above the shoulder joint, the superficial cervical (prescapular) lymph nodes are palpated.