Classifying novel variations of a rare muscle: the sternalis

Abstract

Knowledge and publication of human anatomic variations has become increasingly emphasized in the clinical setting with the intent of decreasing the occurrence of misdiagnosis and surgical complications. We report a previously undocumented variant of sternalis muscle. The sternalis muscle is an anatomical variation of the anterior thoracic wall that is rare, though well‐documented. This inconstant muscle is typically parasternal and superficial to pectoralis major muscle, with its fibers running vertically. Dissection of the anterior thoracic wall on an 83‐year‐old female cadaver revealed bilateral sternalis muscles. The right sternalis muscle has a single belly and can be classified using the Snosek et al. (2014) classification system as a simple type, left single. The left sternalis muscle presented with three muscle bellies, each having a unique pattern of superior attachments. This variation is previously undocumented, and we propose the addition of a new subtype of sternalis classification, as well as a modification to the Snosek et al. (2014) classification scheme to include classifying different muscle bellies when multiple are present.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.