kjpa Korean Journal of Physical Anthropology Korean J Phys Anthropol 1225-150X 2287-626X Korean Association of Physical Anthropologists 10.11637/kjpa.2014.27.4.219 kjpa-27-219 Original Article Anatomical Studies of the Upper and Lower Subscapular Nerves KimJae-Hyoun WooJung-Su HurMi-Sun LeeKyu-Seok Department of Anatomy, Catholic Kwandong University College of Medicine Correspondence to: Kyu-Seok Lee (Department of Anatomy, Catholic Kwandong University College of Medicine) E-mail: kslee@cku.ac.kr 04 2014 20 04 2014 27 4 219 223 18112014 08122014 09122014 Copyright © 2014 Korean Association of Physical Anthropologists 2014 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract

This study aimed to determine the number of branches of the upper and lower subscapular nerves and to classify the spinal nerve compositions of each branch.

Twenty sides of the brachial plexus extracted from Korean adult cadavers were used in this study.

The upper subscapular nerve was composed of three branches in 16 sides(80.0%), composed of four branches in 4 sides (20.0%). The lower subscapular nerve arose from posterior cord with one branch, innervating the subscapularis and the teres major muscles.

In case of the upper subscapular nerve, the first branch was comprised of C5 in 40.0%, C5 and C6 in 60.0%, the second branch was composed of C5 in 15.0%, C5 and C6 in 85.0%, the third branch was arisen from C5 and C6 in 75.0%, C6 in 25.0% and the forth branch appeared in four sided was derived from C6.

The nerve branch innervating the subscapularis muscle was composed of C6 in 55.0%, C5 and C6 in 40.0%, C6 and C7 in 5.0%. The nerve branch innervating the teres major muscle was composed of C6 and C7 in 65.0%, C5, C6 and C7 in 25.0%, and C6 in 10.0%.

The injury was often due to an accidental damage or lesion of the subscapular nerve, these anatomical results may be helpful to predict the involving area of the lesion.

 Upper subscapular nerve Lower subscapular nerve Spinal nerve composition References Chung IH Oh CS Han SH Kim HJ Human Anatomy 5th ed. Hyunmoon 2011 8197 Korean. Bergman RA Thompson SA Afifi AK Saadeh FA Compendium of human anatomic variation Baltimore Urban & Schwarzenberg 1988 140 Woodburne RT Burkel WE Essentials of Human Anatomy 9th ed. New York Oxford University Press 1994 p 121 Moore KL Dalley AF Clinically oriented anatomy 5th ed. Philadelphia Lippincott Williams&Wilkins 2006 7737 Muthoka JM Sinkeet SR Shahbal SH Matakwa LC Og-eng'o JA Variations in branching of the posterior cord of brachial plexus in a Kenyan population J Brachial Plex Peripher Nerve Inj. 20116 1 Tubbs RS Loukas M Shahid K Judge T Pinyard J Anatomy and quantitation of the subscapular nerves Clin Anat. 200720 6569 Saleh DB Callear J McConnell P Kay SP The anatomy of the subscapular nerves: a new nomenclature J Plast Reconstr Aesthet Surg. 201265 10725 Ballesteros LE Ramirez LM Variations of the origin of collateral branches emerging from the posterior aspect of the brachial plexus J Brachial Plex Peripher Nerve Inj. 20072 14 Figures and Tables

Photographs show the number of the branches of the upper subscapular nerve (USN). A: The USN was comprised of the three branches(1st, 2nd, 3rd). B: The USN was comprised of the four branches(1st, 2nd, 3rd, 4th). LSN: lower subscapular nerve

A photograph shows the spinal nerve compositions of the branch of lower subscapular nerve (LSN). The C5 and C6 were distributed to the subscapularis muscle and C5, C6 and C7 were distributed to the teres major muscle.

Spinal nerve compositions and frequency of each branch of the upper subscapular nerve

  C5 C6 Case number
1st branch ◈   8/20(40.0%)
  ◈ ◈ 12/20(60.0%)
2nd branch ◈   3/20(15.0%)
  ◈ ◈ 17/20(85.0%)
3rd branch ◈ ◈ 15/20(75.0%)
    ◈ 5/20(25.0%)
4th branch   ◈ 4/20(20.0%)

Spinal nerve compositions and frequency of the lower subscapular nerve

  Subscapularis m. Teres major m.
C5, C6 8/20(40.0%) –
C6 11/20(55.0%) 2/20(10.0%)
C6, C7 1/20(5.0%) 13/20(65.0%) 5/20(25.0%)
C5, C6, C7 – 5/20(25.0%)