Comparison of the glenohumeral joint and the coxal joint
Both the Glenohumeral joint and the Coxal joint are synovial ball and socket, multiaxial articulations. The glenohumeral joint (Fig 1) is the most moveable joint in the body; its stability therefore is sacrificed. The coxal joint (Fig 2) also has a good range of movement but less than the glenohumeral joint since the coxal joint is restricted by strong ligaments and a deep socket rather than a shallow glenoid cavity of the scapula. Both joints have a rim of fibrocartilage; the glenoid labrum slightly deepens the glenoid cavity, while the Actetabular Labrum enhances the coxal joint. The Labrum and femur and fit snugly together therefore dislocation is rare, unlike the glenohumeral joint with the shallow cavity. Articular hyaline cartilage layers enclose the glenohumeral joint cavity, fossa and humeral head, it is thin and loose, thus allows freedom of movement. Thick articular capsule extends from the rim of the acetabulum to the neck of the femur and completely encloses the coxal joint, which restricts movement. The connecting ends of the humerus and the scapula are encapsulated with a fibrous joint capsule lined internally with synovial membrane containing synovial fluid. ... The coxal joint has more ligaments than the glenohumeral joint, it is considered much stronger but its flexibility and motion are limited. Ligaments reinforcing the capsule of the coxal are shown in the Iliofemoral, Pubofemoral and Ischiofemoral ligaments which attach the femur head into the acetabulum for more stability, these are the outer ligaments.