|Origin||Posterior surface of the lateral border of the scapula|
|Insertion||Greater tubercle of the humerus (inferior aspect)|
|Action||Lateral rotation of the humerus
Stabilisation of the humerus in the glenohumeral joint
Can weakly assist in shoulder adduction
|Nerve||Axillary nerve (C5, C6)|
Circumflex scapular artery
Posterior circumflex artery
Location & Overview
The teres minor is a narrow muscle located in the area of the upper back and shoulder. The distal part of the teres minor is covered by the deltoid. Sometimes muscle fibres from the infraspinatus can be fused with fibres of the teres minor. The teres minor is located inferiorly to the infraspinatus muscle and superior to the teres major muscle  .
The teres minor muscle is one of the four rotator cuff muscles of the shoulder. The remaining three are: the supraspinatus, infraspinatus and subscapularis. A useful acronym to remember the rotator cuff muscles is ‘SITS’. Collectively the rotator cuff muscles are able to provide stabilisation to the glenohumeral joint; which is the ball and socket joint where the head of the humerus sits within the glenoid cavity  .
Origin & Insertion
The teres minor originates on the posterior surface of the scapula, specifically on the lateral border. The insertion is then located on the inferior facet of the greater tubercle of the humerus. The upper fibres of the tendon blend into the capsule of the shoulder joint, whereas the lower fibers insert directly onto the humerus  .
The primary action of the teres minor is lateral rotation (or external rotation) of arm. It also works alongside the other rotator cuff muscles to achieve stabilisation of the humerus in the glenohumeral joint. Additionally, it can provide very weak assistance during adduction of the shoulder   .
Axillary nerve (C5, C6) innervates the teres minor. This nerve originates from the brachial plexus and passes through the quadrangular space into the posterior scapula region .
Blood is supplied to the teres minor from the subscapular artery and one of its branches, the circumflex scapular artery. It also received blood from the posterior circumflex artery  .
Want some flashcards to help you remember this information? Then click the link below:
Teres Minor Flashcards
|↑1, ↑5, ↑7, ↑11||Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513324/|
|↑2, ↑4, ↑8||Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.|
|↑3, ↑6, ↑10, ↑12||Maruvada S, Madrazo-Ibarra A, Varacallo M. Anatomy, Rotator Cuff. [Updated 2021 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441844/|
|↑9||Maruvada S, Madrazo-Ibarra A, Varacallo M. Anatomy, Rotator Cuff. [Updated 2022 Mar 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441844/|