In humans, each shoulder girdle consists of three bones. The bones in the girdle are the clavicle, the humorous and the scapula.
The shoulder girdle is the entire joint system that allows the upper arm to move in a wide range of motion around the body. The shoulder joint is not a single joint like the elbow or knee, but instead is a complex system of bones, muscles, tendons and ligaments that create the widest range of motion of any joint in the human body. Without the shoulder girdle, humans would be unable to reach their arms above their head or out in front of them to perform simple tasks with their hands.
The clavicle is commonly known as the collar bone. This bone helps keep the shoulder over to the side of the body while the scapula is in motion. The humorous is the upper bone in the arm. The top of this bone sits in a ball-and-socket joint, which is similar to the hip joint. The muscles of the shoulder girdle pull the humorous forward, back and up. Finally, the scapula bone is commonly referred to as the shoulder blade. This is a complex bone that moves in multiple directions to make room for the shoulder. The scapula is only attached to the rib cage by two muscles.