Hip Overuse Syndrome

Background: A sudden change in activity or highly repetitive exercise involving the soft tissues surrounding the hip may result in a variety of traction tendonitis scenarios, giving rise to pain and a sense of weakness. Nowhere in sports medicine may the elucidation of a pain generator be more difficult. The sports medicine clinician has the task of excluding intra-articular causes of similar hip pain, soft tissue tumors about the hip, sacroiliac dysfunction, intra-abdominal pathology, and, most commonly, lumbar radiculopathy.

The challenge to set a proper treatment course may prove difficult in athletic individuals who find rest offensive. While there are timetable guidelines for the conditions discussed below, patience and treatment flexibility are required on the part of the medical and rehabilitative team. .

Frequency:In the US: Hip overuse syndrome is a relatively common condition, particularly in people who are physically active.

Functional Anatomy: The hip joint is characterized by a high degree of interlocking due to the ball-and-socket nature of the hip joint. Increased stability is achieved at the cost of mobility. The hip cartilage is amazingly resilient, but the high compressive loads associated with walking, running, and twisting account for the fact that hip osteoarthritis is a common entity.

The hip socket is deepened further by a fibrocartilaginous rim called the labrum. Considering the forces on the hip joint, it is easy to understand that the labrum may be torn with repetitive torsional force. The hip capsule and labrum are reinforced by a series of extremely strong anterior and posterior ligaments that provide moderate tension when an individual stands erect, maximal stability when the hip is extended, and minimal tension when the hip is flexed.

The muscles and tendons about the hip are among the most powerful in the body. They generate high forces in both isometric and concentric modes but must contend with high eccentric loads. These high eccentric loads arise from the sheer demand on these large muscle-tendon units. The fact that most of the muscle-tendon units cross both the hip and knee joints provides the ideal set-up for eccentric acute or repetitive microtrauma strain/sprain.

The iliopsoas tendon attaches medially to the lesser trochanter and is adjacent to a bursa that may become inflamed secondarily during iliopsoas traction tendonitis. Anteriorly, the psoas, iliacus, sartorius, tensor fascia lata, and rectus work in concert for hip flexion. The rectus femoris has a medially directed reflected head that is eccentrically loaded with sudden hip external rotation during contraction.

The adductor longus, pectineus, adductor brevis, adductor magnus, and gracilis act as hip adductors. The piriformis, quadratus, and the superior and inferior gemelli act as hip external rotators.

Muscles posterior to the hip abduct and externally rotate in various combinations. The gluteus maximus, a primary hip extender, has broad insertions into the tensor fascia lata and posterolateral femoral shaft. The hamstrings are hip extenders that cross both the hip and knee joints and are subjected to high eccentric loads.

This article is not meant to discuss inguinal or femoral hernias, but the reader is urged to familiarize himself/herself with the details of anterior inguinal and hip region anatomy. As it leaves the notch, the sciatic nerve is subject to compression from surrounding soft tissue, such as the piriformis muscle.

Sport Specific Biomechanics: Muscles and tendons about the hip are particularly prone to traction tendonitis, as they are significant force generators, involved in most, if not all, sports. Many musculotendinous units of the hip cross both the hip and knee joints, creating the potential for eccentric overload, and often are subjected to ill-conceived exercise programs where the hip is placed at a mechanical disadvantage or is exercised to the point of tendonous microtears.

History: Patients may report gradual or sudden onset of pain in the hip area, concomitant with activity or latently, and these facts may direct diagnostic accuracy. The details of the type and level of athletic activity that gave rise to the painful condition at hand also is important to design a rehabilitation program and avoid the activities that generated the clinical problem in the first place.

Before embarking on a treatment plan, remember that many other conditions can mimic hip overuse syndrome:

In taking the medical history, the clinician should gain a sense of whether lumbar spine, sacroiliac joint, or extra-articular hip problems are primary or secondary.

A preexisting intra-articular hip problem, such as osteoarthritis or a labrum tear, may result in compensating activity in the hip musculature, leading to a secondary hip overuse syndrome. While many patients may correlate an athletic endeavor with their hip pain, there may be a more insidious problem such as early degenerative hip disease or a bony or soft tissue tumor presenting itself after increased physical activity. The patient should be asked about any childhood or adolescent hip disease (eg, congenital hip dysplasia, Legg-Perthes disease, slipped capital femoral epiphysis, traumatic hip dislocation). These remote events may not surface as clinical problems until the hip is stressed with athletic endeavors later in life.

A history of clicking or popping may represent overuse iliopsoas tendonitis, tensor fascia lata/trochanteric bursitis, friction syndrome, or a torn hip labrum. Athletes who load their hips with repeated rotational forces (as in golf, hockey, cheerleading, dance, or baseball) are at risk for either these extra-articular or intra-articular problems. Little information in the history may help to differentiate the condition of a torn labrum versus a snapping iliopsoas tendon, as both occur under the same circumstances. The clinician should, however, consider iliopsoas tendonitis more strongly in athletes, particularly women, who demonstrate ligamentous laxity.

Understanding chronic pain about the athletic hip requires an intimate knowledge of each athlete's training program and sport. Proper diagnosis can be made only through a thorough knowledge of the potential stresses each patient/athlete places on his or her body, and proper diagnosis is necessary to plan a scientifically based rehabilitation program. Some salient points about diagnosis and design of a rehabilitation plan include the following: .

Groin pain offers diagnostic challenges, particularly in those athletes who require repetitive twisting and high- speed turning, as in basketball and hockey. The term groin sprain has been replaced with a greater appreciation of a variety of disorders that affect the hip adductor and inguinal areas. Some authors use the term "sports hernia" widely, when in fact no hernia is present. Suggestions that groin pain should be labeled athletic pubalgia seem to be appropriate.

Insidious unilateral groin pain may start with a single twisting injury to the hip or through a minor incident aggravated by repetitive twisting action. Tenderness may be specific to or generalized to areas of the pubic tubercle, conjoined tendon, midinguinal region, or the superficial inguinal ring. Since the adductor muscles and the inguinal ring are in close proximity, it is difficult in many cases to ascribe the pain generator to traction tendonitis, traction tendonitis leading to attenuation, avulsion, or tearing of the pelvic floor structures. Thus, if an athlete has a predilection to an inguinal hernia, these events may lead to development of a hernia.

The literature is very confusing on this subject, and several theories exist to explain the anatomical cause of the sports hernia. Some authors have implicated, not the adductors, but the injured abdominal musculature. Such confusion has lead to dubious surgical efforts when conservative care of sports hernias have failed. No doubt, there is a family of disorders affecting the groin area of athletes, and more research in this area sorely is needed.

Causes: The quest for fitness, weight loss, and general well-being has resulted in many individuals engaging in increasing physical activity. Weight-bearing activities demand that forces be generated in the area surrounding the hip. These forces can create traction tendonitis or bring preexisting lumbar spine, abdominal, or hip-girdle pathology to the forefront.

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