Rotator Cuff Muscle Anatomy

Overview
Supraspinatus Origin: Supraspinous fossa of scapula
Insertion: Greater tubercle of the humerus (superior aspect)
Action: Abduction of arm & stabilisation of the humerus in glenohumeral joint
Innervation: Suprascapular nerve (C5, C6)
Blood supply: Suprascapular artery
Infraspinatus Origin: Infraspinous fossa
Insertion: Greater tubercle of the humerus (posterior aspect)
Action: External rotation of the arm & stabilisation of the humerus in glenohumeral joint
Innervation: Suprascapular nerve (C5, C6)
Blood supply: Suprascapular and circumflex scapular arteries
Teres minor Origin: Posterior surface of the lateral border of the scapula
Insertion: Greater tubercle of the humerus (inferior aspect)
Action: Eateral rotation of the humerus, stabilisation of the humerus in glenohumeral joint & can very weakly assist in shoulder adduction
Innervation: Axillary nerve (C5, C6)
Blood supply: Subscapular artery, circumflex scapular artery & posterior circumflex humeral artery
Subscapularis Origin: Subscapular fossa
Insertion: Lesser tubercle of humerus
Action: Internal rotation of the shoulder, stabilisation of glenohumeral joint & can very weakly assist in shoulder adduction
Innervation: Upper and lower branches of the subscapular neve (C5, C6, C7)
Blood supply: Subscapular artery

Location & Overview

The rotator cuff refers to a collection of muscles in the shoulder which primarily provide stability to the glenohumeral joint. The head of the humerus is a large spherical head which fits inside a cavity called in the glenoid cavity. The head of the humerus and the glenoid cavity form the glenohumeral joint. The rotator cuff is comprised of the following four muscles: the supraspinatus, infraspinatus, teres minor, and the subscapularis. A useful acronym for memorising these muscles is ‘SITS’ [1]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 [2]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

All four of the rotator cuff muscles connect the scapula to the humerus. The glenoid cavity is a part of the scapula and the head of the humerus is located at the top of the humerus. The rotator cuff muscle tendons blend with the joint capsule. These tendons form a musculotendinous collar which surrounds the superior, posterior, and anterior portions of the joint. The inferior part of the joint does not have a musculotendinous collar and due to this, the inferior part is unprotected. This unfortunately is a cause of most shoulder dislocations, as the humerus can pass inferiorly through this unprotected part [3]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 [4]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Some fibers of the teres minor muscle interlock and connect with those of the infraspinatus. The supraspinatus and subscapularis tendons also interlock and connect as well and they also envelop part of the biceps tendon [5]Kadi R, Milants A, Shahabpour M. Shoulder Anatomy and Normal Variants. J Belg Soc Radiol. 2017 Dec 16;101(Suppl 2):3. doi: 10.5334/jbr-btr.1467. PMID: 30498801; PMCID: PMC6251069..

Origin & Insertion

The supraspinatus originates at the supraspinous fossa of the scapula. It then passes under the acromion and above the glenohumeral joint to insert on the greater tuberosity of the humerus (superior aspect) [6]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 [7]Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [8]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The infraspinatus originates at the infraspinous fossa of the scapula. It then inserts on the greater tuberosity of the humerus (posterior aspect) just inferior to the insertion of the supraspinatus [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 [10]Williams JM, Sinkler MA, Obremskey W. Anatomy, Shoulder and Upper Limb, Infraspinatus Muscle. [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [11]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The teres minor originates on the lateral border of the scapula and then inserts on the greater tuberosity of the humerus (inferior aspect) just inferior to the insertion of the infraspinatus [12]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 [13]Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available … Continue reading [14]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The subscapularis is the only rotator cuff muscle originating on the anterior side of the scapula. It originates at the subscapular fossa and then inserts on the lesser tubercle of the humerus [15]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 [16]Aguirre K, Mudreac A, Kiel J. Anatomy, Shoulder and Upper Limb, Subscapularis Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [17]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Actions

The primary role of all the rotator cuff muscles is to stabilise the head of the humerus in the glenoid cavity. This stabilisation is achieved by compressing the head of the humerus against the glenoid [18]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 [19]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The supraspinatus is responsible for abduction of the arm. The supraspinatus is the primary mover in this abduction during the first 0 to 15 degrees of shoulder abduction. Past this first 0 to 15 degrees, the deltoid muscle is then mainly responsible for abduction of the arm [20]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 [21]Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [22]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The infraspinatus is responsible for lateral rotation of the shoulder (also known as external rotation) [23]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 [24]Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [25]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The teres minor is also responsible for lateral rotation of the shoulder (also known as external rotation) [26]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 [27]Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available … Continue reading [28]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

The subscapularis muscle is responsible for medial rotation of the shoulder (also known as internal rotation) [29]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 [30]Aguirre K, Mudreac A, Kiel J. Anatomy, Shoulder and Upper Limb, Subscapularis Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [31]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

In addition to the primary actions of the rotator cuff muscles mentioned above, the teres minor and subscapularis have also been demonstrated to be able to provide very weak assistance during shoulder adduction [32]Aguirre K, Mudreac A, Kiel J. Anatomy, Shoulder and Upper Limb, Subscapularis Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [33]Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.

Innervation

The innervation of the infraspinatus and supraspinatus is the suprascapular never (C5, C6, C7). The suprascapular nerve originates from the superior trunk of the brachial plexus and passes through the suprascapular foramen [34]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 [35]Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading [36]Williams JM, Sinkler MA, Obremskey W. Anatomy, Shoulder and Upper Limb, Infraspinatus Muscle. [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading.

The innervation of the teres minor is the axillary nerve (C5, C6). The axillary nerve originates from the posterior cord of the brachial plexus and passes through the quadrangular space into the posterior scapula region [37]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 [38]Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available … Continue reading.

The upper and lower branches of the subscapular neve (C5, C6, C7) innervate the subscapularis muscle. This nerve originates from the posterior cord of the brachial plexus [39]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 [40]Aguirre K, Mudreac A, Kiel J. Anatomy, Shoulder and Upper Limb, Subscapularis Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading.

Blood Supply

Blood is supplied to the supraspinatus and infraspinatus muscles via the suprascapular artery. This is a branch of the thyrocervical trunk which is a major branch of the subclavian artery. The thyrocervical trunk originates at the base of the neck and enters the region of the posterior scapula just superiorly to the suprascapular foramen [41]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. The infraspinatus also receives blood from the circumflex scapular artery. The circumflex scapular artery comes around the lateral border of the scapula and enters into the infraspinous fossa [42]Williams JM, Sinkler MA, Obremskey W. Anatomy, Shoulder and Upper Limb, Infraspinatus Muscle. [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. … Continue reading.

The teres minor gets its blood supply via the subscapular artery, the circumflex scapular artery and the posterior circumflex humeral artery. The circumflex scapular artery is a branch of the subscapular artery. The subscapular artery and the posterior circumflex humeral artery both arise from the third and most distal part of the axillary artery. The axillary artery travels along the inferior margin of the subscapularis muscle [43]Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available … Continue reading.

The subscapularis muscle gets is blood supply via the subscapular artery. The subscapular artery is the largest branch of the axillary artery. The subscapular artery originates from the third part of the axillary artery. The axillary artery travels along the inferior margin of the subscapularis muscle and divides into the circumflex scapular artery and the thoracodorsal artery [44]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.

Images

rotator cuff muscles

Pictured here we can see all four of the rotator cuff muscles: the supraspinatus, infraspinatus, teres minor and subscapularis. The left side of this picture is from a posterior view (the back) and the right hand side is from an anterior view (the front).

rotator cuff oragins and insertions

Pictured here we can see the origin and insertion points of the rotator cuff muscles. The origins are highlighted in red and the insertions are highlighted in blue. The supraspinatus originates at the supraspinous fossa of the scapula and inserts on the greater tuberosity of the humerus (superior aspect). The infraspinatus originates at the infraspinous fossa and inserts on the greater tuberosity of the humerus (posterior aspect) just inferior to the insertion of the supraspinatus. The teres minor originates on the lateral border of the scapula and then inserts on the greater tuberosity of the humerus (inferior aspect) just inferior to the insertion of the infraspinatus. The subscapularis originates at the subscapular fossa and then inserts on the lesser tubercle of the humerus.

Want some flashcards to help you remember this information? Then click the link below:
Supraspinous Flashcards
Infraspinatus Flashcards
Teres Minor Flashcards
Subscapularis Flashcards

References

References
1, 3, 6, 9, 12, 15, 18, 20, 23, 26, 29, 34, 37, 39, 41, 44 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/
2, 4, 8, 11, 14, 17, 19, 22, 25, 28, 31, 33 Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017
5 Kadi R, Milants A, Shahabpour M. Shoulder Anatomy and Normal Variants. J Belg Soc Radiol. 2017 Dec 16;101(Suppl 2):3. doi: 10.5334/jbr-btr.1467. PMID: 30498801; PMCID: PMC6251069.
7, 21, 24, 35 Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537202/
10, 36, 42 Williams JM, Sinkler MA, Obremskey W. Anatomy, Shoulder and Upper Limb, Infraspinatus Muscle. [Updated 2021 Aug 13]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513255/
13, 27, 38, 43 Juneja P, Hubbard JB. Anatomy, Shoulder and Upper Limb, Arm Teres Minor Muscle. [Updated 2022 May 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513324/
16, 30, 32, 40 Aguirre K, Mudreac A, Kiel J. Anatomy, Shoulder and Upper Limb, Subscapularis Muscle. [Updated 2021 Aug 7]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513344/