Teres Minor Muscle Anatomy

Overview
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)
Artery Subscapular artery
Circumflex scapular artery
Posterior circumflex artery

Location

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 [1]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 … Continue reading [2]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017..

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 [3]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: … Continue reading [4]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017..

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 [5]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 … Continue reading [6]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: … Continue reading.

Actions

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 [7]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 … Continue reading [8]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017. [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: … Continue reading.

Innervation

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 [10]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: … Continue reading.

Blood Supply

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 [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 … Continue reading [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: … Continue reading.

Images

teres minor muscle

Here we can see the teres minor muscle in isolation from a posterior view.

teres minor origin and insertion

The teres minor originates at the lateral border of the scapula (displayed in red) and inserts at the inferior facet of greater tubercle of the humerus (displayed in blue).

three posterior rotator cuff muscles

Teres minor is one of the four rotator cuff muscles. Pictured here are the three posterior rotator cuff muscles (supraspinatus, infraspinatus and teres minor). Subscapularis is visible from an anterior view.

Subscapularis

Subscapularis is the final rotator cuff muscle, visible from an anterior view.

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Teres Minor Flashcards

References

References
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/