A newly reported muscle: an accessory infraspinatus or a deep layer of the latissimus dorsi?

Surg Radiol Anat. 2022 Apr;44(4):617-620. doi: 10.1007/s00276-022-02917-8. Epub 2022 Mar 10.

Abstract

The infraspinatus muscle is a component of the rotator cuff; the latissimus dorsi muscle is the largest muscle of the back. These muscles are not considered very morphologically variable. However, the latissimus dorsi has more frequent variations than the infraspinatus. During anatomical dissection, an additional muscle structure was found. It originated on the medial border of the scapula, ran under the scapular spine, and ended on the greater tubercle next to the infraspinatus attachment. We will discuss the anatomical and physiological relationships of this muscle. We believe that our finding underlines the importance of different muscle variants in the rotator cuff region. Level of evidence: II basic science research.

Keywords: Accessory infraspinatus muscle; Latissimus dorsi; Rotator cuff; Shoulder anatomy.

MeSH terms

  • Humans
  • Rotator Cuff
  • Rotator Cuff Injuries*
  • Scapula / physiology
  • Shoulder Joint* / anatomy & histology
  • Superficial Back Muscles*