Teres Major Muscle – Attachments, Action & Innervation

Author: Scott A. Sheffield MS

Last update:

Teres major is a thick and ovoid muscle in the upper arm.

Despite their similar names, teres major has different actions and innervation from the teres minor.

The teres major muscle is mainly responsible for the medial rotation of the arm and it also contributes to static posture and arm-swinging.

image descriptionTeres Major Muscle

An image showing the Teres major muscle (highlighted) attached to the upper limb along with other muscles (Trapezius, Deltoid, Triceps brachii, Latissimus dorsi)
An image showing the Teres major muscle (highlighted) attached to the upper limb along with other muscles (Infraspinatus, Teres minor, Triceps brachii, Latissimus dorsi)
An image showing the Teres major muscle (highlighted) attached to the upper limb along with other muscles (Triceps brachii, Latissimus dorsi)
An image showing the Teres Major Muscle attached to the upper limb
1
2
3
4

Attachments of Teres Major Muscle Origin & Insertion

image descriptionOrigin: (proximal attachments)
Lower lateral border and inferior angle of the scapula.

image descriptionInsertion: (distal attachments)
Medial lip of the intertubercular (bicipital) groove of the anterior humerus.

An image showing the Teres major muscle (highlighted) attached to the upper limb along with other muscles (Trapezius, Deltoid, Triceps brachii, Latissimus dorsi)
An image showing the Teres Major Muscle attached to the upper limb
An image showing the Teres major muscle Origin on the upper limb
An image showing the Teres major muscle Insertion on the upper limb
1
2
3
4

Worried about remembering all of this information? Study smarter with these upper extremity muscle reference charts.

Actions of Teres Major:

image descriptiona. Adducts the arm at the shoulder (glenohumeral) joint.

image descriptionb. Medially rotates the arm at the shoulder (glenohumeral) joint.

image descriptionc. Extends the arm at the shoulder (glenohumeral) joint.

Innervation of Teres Major:

image descriptionNerves to the muscle:
Lower subscapular nerve.
image descriptionNerve roots:
C5, C6, and C7.
An image showing the Lower subscapular nerve coming out of the brachial plexus
An image showing the Lower subscapular nerve coming out of the brachial plexus
1
2
Related Articles
Featured Image Posterior View Trapezius
Trapezius Muscle

An interactive demonstration of the Trapezius Muscle (Insertion, Origin, Actions & Innervations) featuring the iconic GBS illustrations.
Featured image showing three images of the posterior back and arm with trees minor and origin and insertion of teres minor.
Teres Minor Muscle – Attachments, Actions & Innervation

Teres minor is one of four muscles that comprise what’s called the Rotator Cuff. It’s narrow and elongated in shape and sometimes may be fused with infraspinatus. Its main function is to stabilize the humerus in the glenoid fossa when the shoulder moves.
Feature image showing three images of the posterior back and arm with supraspinatus and supraspinatus origin and insertion.
Supraspinatus Muscle – Attachments, Actions & Innervation

Supraspinatus is a small muscle of the upper arm. It’s one of the four muscles that make up the rotator cuff. It arises from the supraspinatus fossa to eventually inserts on the greater tubercle of the humerus.