upper subscapular nerve
{{Short description|Nerve of upper limb}}
{{Infobox nerve
| Name = Upper subscapular nerve
| Latin = nervus subscapularis superior
| Image = Gray807.png
| Caption = Plan of brachial plexus. (Label for upper subscapular nerve at bottom center.)
| Image2 =
| Caption2 =
| Innervates = Subscapularis
| BranchFrom = Posterior cord
| BranchTo =
}}
The upper (superior) subscapular nerve is the first branch of the posterior cord of the brachial plexus. The upper subscapular nerve contains axons from the ventral rami of the C5 and C6 cervical spinal nerves. It innervates the superior portion of the subscapularis muscle. The inferior portion of the subscapularis is innervated by the lower subscapular nerve.
Structure
The axons which form the upper subscapular nerve travel from the ventral rami of C5 and C6.{{Cite book|title=Gray's anatomy : the anatomical basis of clinical practice|editor=Standring, Susan|publisher=Elsevier|year=2016|isbn=978-0-7020-5230-9|edition=Forty-first|location=Philadelphia|oclc=920806541}} They join at the upper trunk and move through its posterior division to form the posterior cord, along with the other two posterior divisions of the middle and lower trunks. The axons then branch from the posterior cord and form the upper subscapular nerve.{{Citation|last=Hentz|first=Vincent R.|title=Chapter 20 - Adult and Obstetrical Brachial Plexus Injuries|date=2006-01-01|url=http://www.sciencedirect.com/science/article/pii/B9780443066672500289|work=Peripheral Nerve Surgery|pages=299–317|editor-last=Slutsky|editor-first=David J.|place=Philadelphia|publisher=Churchill Livingstone|language=en|isbn=978-0-443-06667-2|access-date=2021-01-10|editor2-last=Hentz|editor2-first=Vincent R.}}
Function
The upper subscapular nerve innervates the superior portion of the subscapularis muscle.{{Cite journal|date=2019-07-01|title=Innervation of the subscapularis: an anatomic study|journal=JSES Open Access|language=en|volume=3|issue=2|pages=65–69|doi=10.1016/j.jses.2019.02.001|issn=2468-6026|doi-access=free|last1=Sager|first1=Brian|last2=Gates|first2=Stephen|last3=Collett|first3=Garen|last4=Chhabra|first4=Avneesh|last5=Khazzam|first5=Michael|pmid=31334431|pmc=6620204}}
Clinical significance
A lesion to the upper subscapular nerve can cause a reduced ability to medially rotate at the shoulder joint, however this function is supplemented by other muscles.{{Citation needed|date=January 2021}}
Additional images
File:Brachial plexus.svg|Brachial plexus
File:Gray809.png|The right brachial plexus (infraclavicular portion) in the axillary fossa; viewed from below and in front.