The shoulder was designed for mobility, which also makes it one of the most unstable joints in the body. The shoulder consists of three osseous joints and one articulation. The stability of the shoulder is dependent on the muscles, ligaments, the glenoid labrum and the joint capsule. There are varying degrees of instability as well as various types of instability. The three main types of instabilities are Unidirectional instabilities, multidirectional instabilities, and subluxation.