The Hip Joint
Anatomy, common injuries and postrehab strategies.

The structure of the hip joint consists of the acetabulum (socket) and the femoral head (ball). The acetabulum is the socket in the pelvis formed by three innominate bones: the ilium, the ischium and the pubis. The socket faces laterally and also slightly inferiorly and anteriorly. The femoral head is roughly semispherical, with a short “neck of the femur” angling the head anteriorly, medially and superiorly to fit into the socket. The angle of inclination is created by the head of the femur and the long bone of the femur. This angle is normally 125 degrees in adults, greater in infants. It may be slightly less than 125 degrees in women, owing to their wider pelvises.

strong. Its strongest aspects are the anterior and superior aspects, reinforced primarily by the two strongest ligaments, the iliofemoral and ischiofemoral ligaments (Norkin & Levangie 1992). Positioning. The hip joint is most congruent under high loads and less so under low loads. It is most stable in quadruped (structurally) and in hip extension (owing to ligamentous tautness). Therefore, there is a greater chance of injury during adduction and flexion.

the outside of the greater trochanter and the firm tendon that passes over this bone. When the bursa sac becomes inflamed, the client may experience pain each time the tendon moves over the bone. Because a client with hip bursitis moves this tendon with each step, hip bursitis symptoms can be quite painful. Clients can prevent bursitis symptoms through good conditioning habits involving strengthening and lengthening of all the myofascial structures. At the same time, they should avoid overuse and implement cross-training.
Causative Factors

The hip joint has three degrees of freedom; that is, it moves in three different planes: 1. sagittal plane: flexion/extension 2. frontal plane: abduction/adduction 3. transverse plane: external/internal rotation

The following muscles all act at the hip joint to produce its various motions. Extensors. Gluteus maximus, hamstrings (long head of biceps femoris, semitendinosus, semimembranosus). Flexors. Iliopsoas (iliacus and psoas), rectus femoris, tensor fasciae latae, sartorius. Adductors. Pectineus, adductor brevis, adductor longus, gracilis, adductor magnus. Abductors. Gluteus medius, gluteus minimus, tensor fasciae latae. External Rotators. Obturatorius internus and externus, gemellus superior and inferior, quadratus femoris, piriformis. Internal Rotators. The anterior portion of the gluteus medius and the tensor fasciae latae contribute to this action, but no muscle does internal rotation as its primary function (Moore 1992).