Shoulder Muscles - Deltoids
The shoulder muscles (deltoideus muscles, deltoids or delts) have its name from its delta shape (triangular shape) and is located on top of the shoulder joint. Its function is to elevate the arm. The side head does most of the work until the arm reaches 60 degrees. From there, the front and the rear head do most of the work. The deltoid muscle forms the round contour of the human shoulder. Find exercises and information about other muscles at weight training main.