Muscle
Teres minor
Small external rotator within the cuff
High-yield
Among the four cuff muscles, teres minor is the one supplied by the axillary nerve.
Overview
Teres minor lies just below infraspinatus and reaches the lower part of the greater humeral tubercle. It assists outward rotation and helps the cuff keep the humeral head seated in the shallow socket.
Learning this group? Read The rotator cuff muscles, explained.
Reference facts
- Origin
- Posterior scapula alongside the upper part of its lateral border
- Insertion
- Inferior facet of the greater humeral tubercle, with lower fibers reaching adjacent humerus
- Action
- Externally rotates the arm and assists shoulder stabilization
- Innervation
- Axillary nerve, mainly C5–C6
- Blood supply
- Circumflex scapular and posterior circumflex humeral arterial branches
Clinical correlation
Quadrangular-space compression can affect the axillary nerve and teres minor. However, isolated teres minor wasting on an MRI can have other causes; the image alone does not establish that syndrome.
Frequently asked questions
What does the teres minor do?
The teres minor externally rotates the arm and assists shoulder stabilization.
What nerve innervates the teres minor?
The teres minor is innervated by the axillary nerve, mainly C5–C6.
Where does the teres minor attach?
Origin: Posterior scapula alongside the upper part of its lateral border. Insertion: Inferior facet of the greater humeral tubercle, with lower fibers reaching adjacent humerus.
What is the blood supply of the teres minor?
The teres minor is supplied by the circumflex scapular and posterior circumflex humeral arterial branches.