There are movable joints that allow a person to bend or twist. However, some joints allow us to move freely, while others allow us only little movement. There are two types of joints. One of the joints is called the hinge joint and tolerates back and forth movements in a single direction or connects the upper body, the humerus, the ulna, and the lower body. A ball and socket joint is also another joint that allows for many movements in all possible directions like a ball in a socket (Marieb 259). Shoulders and hips are the example of the ball and socket joint. Muscles are connected to bones via tendons, bones are connected to each other via other bones themselves. Additionally, the bones are held together in the joint by ligaments. The ligament is like a band of tissue or the white part of the muscle. Between the joints of a bone you can find rubbery tissue called cartilage. Cartilage is like the cushion for the bone where it acts as a shock