Muscle
Infraspinatus
Rotator cuff - lateral rotation
High-yield
Chief lateral rotator of the arm; suprascapular nerve (shared with supraspinatus).
Overview
A rotator cuff muscle filling the infraspinous fossa that laterally rotates the arm and resists posterior dislocation.
Learning this group? Read The rotator cuff muscles, explained.
Reference facts
- Origin
- Infraspinous fossa of the scapula
- Insertion
- Middle facet of the greater tubercle of the humerus
- Action
- Laterally rotates the arm; stabilises the glenohumeral joint
- Innervation
- Suprascapular nerve (C5, C6)
- Blood supply
- Suprascapular and circumflex scapular arteries
Frequently asked questions
What does the infraspinatus do?
The infraspinatus laterally rotates the arm; stabilises the glenohumeral joint.
What nerve innervates the infraspinatus?
The infraspinatus is innervated by the suprascapular nerve (C5, C6).
Where does the infraspinatus attach?
The infraspinatus originates from the infraspinous fossa of the scapula and inserts on the middle facet of the greater tubercle of the humerus.
What is the blood supply of the infraspinatus?
The infraspinatus is supplied by the suprascapular and circumflex scapular arteries.