What are Rear Delts & Why Do They Matter

The rear delt is an often underdeveloped, under-appreciated part of the shoulder system. “Delt” is gym slang for deltoid. The deltoid muscle most simply is the rounded musculature around the shoulder. The posterior portion of the deltoid (the rear delt) is a particularly helpful antagonist to the pectoral muscles; a fan favorite.  The rear delt is