Muscle
Teres major
Pulls the arm inward and backward
High-yield
Teres major lies below teres minor and forms the lower boundary of the quadrangular space. It is outside the four-muscle rotator cuff.
Overview
Teres major runs from the lower scapula to the front of the proximal humerus. It works with latissimus dorsi to bring the arm toward the body, turn it inward and move it backward.
Reference facts
- Origin
- Posterior aspect of the scapula near its inferior angle
- Insertion
- Medial lip of the humeral intertubercular groove
- Action
- Adducts, internally rotates and assists extension of the arm
- Innervation
- Lower subscapular nerve, usually C5–C6 with variable C7 contribution
- Blood supply
- Subscapular arterial branches, including thoracodorsal and circumflex scapular contributions
Frequently asked questions
What does the teres major do?
The teres major adducts, internally rotates and assists extension of the arm.
What nerve innervates the teres major?
The teres major is innervated by the lower subscapular nerve, usually C5–C6 with variable C7 contribution.
Where does the teres major attach?
Origin: Posterior aspect of the scapula near its inferior angle. Insertion: Medial lip of the humeral intertubercular groove.
What is the blood supply of the teres major?
The teres major is supplied by the subscapular arterial branches, including thoracodorsal and circumflex scapular contributions.