Upper BackSource-checked
Teres major
Teres major
Pronunciation: TEH-reez MAY-jor
For beginners
Nicknamed 'lat's little helper' because it copies the latissimus dorsi's action of pulling the arm down and in.
Show the advanced explanation
Unlike its neighbour teres minor (a rotator-cuff external rotator), teres major is an internal rotator and is NOT part of the rotator cuff.
Structure & function
- Location
- A thick muscle along the lower outer edge of the shoulder blade, below teres minor.
- Origin
- Inferior angle / lower lateral border of the scapula.
- Insertion
- Intertubercular groove of the humerus (near the latissimus dorsi).
- Main action(s)
- Extends, adducts, and internally rotates the arm — assisting the latissimus dorsi.
- Joint(s) crossed
- Glenohumeral joint
- Movement plane
- multiple
- Innervation
- Lower subscapular nerve (C5–C6)
- In daily movement
- Assists pulling the arm down and back.
- In exercise
- Assists the lats in pull-ups, pulldowns, and rows.
- Commonly confused with
- Very commonly confused with teres minor — same neighbourhood, opposite rotation; teres major is NOT a cuff muscle.
- Common misconceptions
- 'Teres major helps abduct like teres minor' is wrong — it adducts and internally rotates.
Exercises that use this muscle
As a secondary / stabilizer
- Bent-Over Barbell Row (secondary)
- Lat Pulldown (secondary)
⚠ Safety note
Rarely a source of isolated problems; shoulder pain overall should be assessed if persistent.
Sources
“The teres major extends, adducts, and medially rotates the humerus, assisting the latissimus dorsi.”
Anatomy and Physiology 2e — OpenStax, Rice University · Ch. 11.5 Muscles of the Pectoral Girdle and Upper Limbs
Peer-reviewed textbook · License: CC BY-NC-SA 4.0 · Last checked 2026-07-19
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