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EVIDENCE INFORMED PRACTICE PAIN IN THE
LATERAL HIP AND ITB DIAGNOSES AND REHABILITATION
BY CHRISTOPHER NORRIS PHD MCSP
COMMON DIAGNOSES Clients presenting with pain around the greater trochanter (GT) on the outer (lateral) aspect of the hip are often seen in the clinic. Typical conditions include iliotibial band syndrome (ITBS), external snapping hip, gluteus medius tendinopathy, and greater trochanteric pain syndrome (GTPS). These diagnoses really refer to the same structures and may occur separately or in association with hip impingement (femoroacetabular impingement or FAI), degenerative changes to the joint, and labral conditions. In these latter conditions the quality of movement at the hip changes and, in turn, muscle function is altered giving primary pain anteriorly and secondary pain laterally. Low back conditions may also refer pain into the lateral thigh so screening tests should rule out the low back as a cause of pain. To understand lateral hip pain and treat it successfully we need to examine the structure and function of the area.
APPLIED ANATOMY Hip joint Alignment of the pelvis on the femur (femoral pelvic alignment) during single-leg standing is maintained by a balance of the compression forces created by weight- bearing activities, and those of the lateral hip structures. The hip can be thought of as a pivot – like a seesaw – with the client’s body weight acting on one side and muscle force on the other.
This set-up subjects the hip joint to considerable forces
when weight-bearing. When standing on one leg, forces between 1.8–3.0 times body weight occur, and in walking these increase to 3.3–5.5 times body weight (1). The femoral head is smaller in females while the pelvis is wider. This configuration changes leverage to significantly reduce the mechanical advantage of the abductor muscles (Fig. 1). With a lower mechanical advantage the muscles must work harder to maintain hip alignment, and this increased muscle work acting over a smaller head size results in greater femoral head pressures in females (2), perhaps explaining why the incidence of GTPS has been cited as four times greater in females than in males (3).
Lateral musculature The lateral muscles are arranged in three layers (Table 1),
which control the femoral head (ball) within the acetabulum (socket) and stabilise the pelvis on the femur. Joint stability is said to be better produced by those muscles lying close to the axis of rotation of the joint (4), and in the case of the hip it is the deep lateral rotators that have this role. The iliacus muscle is normally thought of as an anterior structure, but it actually consists of two sets of fibres with the lateral portion more active in torque production (twisting) and the medial fibres being linked to stability. This stability role is emphasised by the fact that the medial fibres are predominantly slow twitch in nature. The ilocapsularis (also called iliacus minor) is a small muscle that lies beneath the rectus femoris and attaches directly to the joint capsule. It functions to tighten the joint capsule and has been shown to degrade in cases of hip dysplasia (5,6).
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This article provides a review of the common diagnoses of lateral hip and ITB pain and rehabilitation techniques with reference to the anatomical structures involved.
Figure 1: The iliotibial band.