Origin | Supraspinous fossa of scapula |
Insertion | Greater tubercle of the humerus (superior aspect) |
Action | Abduction of arm Stabilisation of the humerus in the glenohumeral joint |
Nerve | Suprascapular nerve (C5, C6) |
Artery | Suprascapular artery |
Location & Overview
The supraspinatus is a relatively small muscle which is located in the upper back and shoulder. The supraspinatus travels under the acromion which can make it vulnerable to impingement. The space in this gap of the acromion is called the ‘subacromial space’ [1] [2] [3].
The supraspinatus is one of the four muscles which form the rotator cuff of the shoulder. The remaining three rotator cuff muscles are: the subscapularis, teres minor and infraspinatus. A useful acronym to remember these muscles is “SITS”. The spine of the scapula separates the infraspinatus muscle from the supraspinatus muscle [4].
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).
Origin & Insertion
The supraspinatus originates at the supraspinous fossa of scapula (a shallow depression in the body of the scapula above the scapula’s spine). The supraspinatus’ tendon then passes under the acromion and inserts at the superior facet of the greater tubercle of the humerus [5] [6] [7].
The supraspinatus originates at the supraspinous fossa of scapula (marked in red) and inserts at the superior facet of the greater tubercle of the humerus (marked in blue).
Actions
The primary action of the supraspinatus is abduction of arm and stabilisation of the humerus within the glenohumeral joint [8] [9].
Innervation
The suprascapular nerve (C5, C6) innervates the supraspinatus. This nerve also innervates the infraspinatus muscle (one of the other rotator cuff muscles) [10].
Blood Supply
Blood is supplied from the suprascapular artery. The suprascapular artery is a branch of the thyrocervical trunk. The thyrocervical trunk is a major branch of the subclavian artery. This artery originates at the base of the neck [11].
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Supraspinatus Flashcards
References
↑1, ↑4, ↑8, ↑10, ↑11 | 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/ |
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↑2 | Creech JA, Silver S. Shoulder Impingement Syndrome. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554518/ |
↑3, ↑6, ↑9 | Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017. |
↑5 | 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/ |
↑7 | Jeno SH, Munjal A, Schindler GS. Anatomy, Shoulder and Upper Limb, Arm Supraspinatus Muscle. 2021 Aug 7. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 30725887. |