Suprascapular nerve
The suprascapular nerve is a nerve that branches from the upper trunk of the brachial plexus. It is responsible for the innervation of two of the muscles that originate from the scapula, namely the supraspinatus and infraspinatus muscles.
| Suprascapular nerve | |
|---|---|
 The suprascapular, axillary, and radial nerves. (Suprascapular labeled at upper left.) | |
 The right brachial plexus with its short branches, viewed from in front. (Suprascapular labeled at upper left.) | |
| Details | |
| From | upper trunk (C5–C6) of brachial plexus |
| Innervates | supraspinatus, infraspinatus |
| Identifiers | |
| Latin | nervus suprascapularis |
| TA98 | A14.2.03.014 |
| TA2 | 6411 |
| FMA | 37025 |
| Anatomical terms of neuroanatomy | |
Structure
The suprascapular nerve arises from the upper trunk of the brachial plexus which is formed by the union of the ventral rami of the fifth and sixth cervical nerves. After branching from the upper trunk, the nerve passes across the posterior triangle of the neck parallel to the inferior belly of the omohyoid muscle and deep to the trapezius muscle. It then runs along the superior border of the scapula through the suprascapular canal,[1] in which it enters via the suprascapular notch inferior to the superior transverse scapular ligament and enters the supraspinous fossa.[2] It then passes beneath the supraspinatus, and curves around the lateral border of the spine of the scapula through spinogleniod notch to the infraspinous fossa.
Function
The suprascapular nerve is a mixed peripheral nerve containing motor and sensory components.
Motor innervation
- Supraspinatus muscle[2]
- Infraspinatus muscle (through the spinoglenoid notch)[2]
Sensory innervation
- Acromioclavicular joint[2]
- Glenohumeral joint[2] (shoulder joint)
In the supraspinous fossa it gives off two branches to the supraspinatus muscle and in the infraspinous fossa it gives off two branches to the infraspinatus muscle.
Clinical significance
- Suprascapular paralysis, causing back pain, problems with abduction and external rotation of the humerus, and wasting away of supraspinatus and infraspinatus. Supraspinatus muscle helps in 0°-15° arm abduction. And Infraspinatus helps in lateral rotation (external rotation) of humerus.
- Suprascapular nerve entrapment syndrome, causing shoulder pain and localized muscular atrophy of the supraspinatus and infraspinatus muscles. This can potentially develop due to suprascapular nerve being entrapped and compressed within the suprascapular canal potential anatomical entrapment sites.[1]
Additional images
Suprascapular and axillary nerves of right side, seen from behind.
Brachial plexus with courses of spinal nerves shown
External links
- Suprascapular nerve at the Duke University Health System's Orthopedics program
References
This article incorporates text in the public domain from page 932 of the 20th edition of Gray's Anatomy (1918)
- Al-Redouan, Azzat; Holding, keiv; Kachlik, David (2020). ""Suprascapular canal": Anatomical and topographical description andits clinical implication in entrapment syndrome". Annals of Anatomy. 233: 151593. doi:10.1016/j.aanat.2020.151593. PMID 32898658.
- Avery, BW; Pilon, FM; Barclay, JK (November 2002). "Anterior coracoscapular ligament and suprascapular nerve entrapment". Clinical Anatomy. 15 (6): 383–6. doi:10.1002/ca.10058. PMID 12373728. S2CID 9826767.