|Origin||Lower third of lateral border of Scapula|
|Insertion||Medial Lip of intertubercular sulcus of the Humerus|
|Nerve supply||Lower subscapular nerve|
|Actions||Adduction and Medial rotation of the arm and stabilizes shoulder joint|
Teres Major Origin and Insertions – Image modified from BodyParts3D, © The Database Center for Life Science licensed under CC Attribution-Share Alike 2.1 Japan
Teres major attaches at Medial (lesser crest) lip while pectoralis major attaches at Lateral lip.
When this muscle contracts, the Humerus is pulled towards the body (adduction) and as it’s attached on the anterior side anterior side is pulled medially resulting in medial rotation of the arm.
Check previous lesson for Subscapularis muscle and Next lesson for Teres Minor muscle.