This article is about training shoulders also known as the "deltoids". The deltoids are a large thick and powerful group of muscles. They are triangular in shape with a coarse texture.
They originate from the "clavicle" (collarbone) and the spine of the "scapula" (shoulder blade). Covering the outer side of the shoulder it gives the shoulder a rounded-look in appearance.
They insert into the "humorous" (upper arm bone) and are used to raise the arm outward from the side.
They work with the "pectoralis major" (upper chest muscles) to move the arm forward and work with the "teres major" (upper back muscles) and "latissimus dorsi" (low end of the lat muscles) to move the arm back in position.