|Origin||Inferior angle of the medial border of the scapula|
|Insertion||Medial crest of the intertubercular groove (bicipital groove)|
|Action||Shoulder internal rotation
|Nerve||Lower subscapular nerve (C5, C6, C7)|
|Artery||Circumflex scapular artery or the thoracodorsal artery|
Location & Overview
There teres major muscle is a small muscle of the upper back, which attaches to the humerus and the scapula. It is a thick muscle which is somewhat flat in shape. It is one of seven scapulohumeral muscles. The scapulohumeral muscles are: the deltoid, coracobrachialis, infraspinatus, subscapularis, supraspinatus, teres minor and the teres major. It has somewhat of a synergistic action with the latissimus dorsi so is occasionally referred to as the ‘lat’s little helper’  .
Origin & Insertion
The teres major originates at the inferior angle of the medial border of the scapula and inserts at the medial crest of the intertubercular groove (also known as the bicipital groove). The bicipital groove is where the long head tendon of the biceps brachii is located  .
The teres major is innervated by the lower subscapular nerve (C5, C6, C7) .
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Teres Major Flashcards
|↑1||Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.|
|↑2, ↑4, ↑6, ↑8||Wu JG, Bordoni B. Anatomy, Shoulder and Upper Limb, Scapulohumeral Muscle. [Updated 2021 Sep 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK546633/|
|↑3, ↑5||Donohue BF, Lubitz MG, Kremchek TE. Sports Injuries to the Latissimus Dorsi and Teres Major. Am J Sports Med. 2017 Aug;45(10):2428-2435. doi: 10.1177/0363546516676062. Epub 2016 Dec 20. PMID: 28125914.|
|↑7, ↑9||Dancker M, Lambert S, Brenner E. The neurovascular anatomy of the teres major muscle. J Shoulder Elbow Surg. 2015 Mar;24(3):e57-67. doi: 10.1016/j.jse.2014.07.001. Epub 2014 Sep 17. PMID: 25240812.|