The deltoids are the muscles that cover the front, back and side of the shoulder joint — and they are essential for everyday movements like raising your arms, lifting a child or carrying groceries.

Your deltoid muscles make up a main muscle group in your upper body. They’re connected with many other muscles and bones in your upper back, neck, and shoulder region and are extremely mobile.

Lateral raises also minimally use the posterior (back) deltoid, the supraspinatus (rotator cuff muscle), and serratus anterior (muscle above your ribs and under your armpit). In order to gain true ...