The Clinical Syndrome

The gluteus maximus muscle’s primary function is hip extension. It originates at the posterior aspect of the dorsal ilium, the posterior superior iliac crest, the posterior inferior aspect of the sacrum and coccyx, and the sacrotuberous ligament. The muscle inserts on the fascia lata at the iliotibial band and the gluteal tuberosity on the femur. The muscle is innervated by the inferior gluteal nerve.

The gluteus maximus muscle is susceptible to trauma and to wear and tear from overuse and misuse and to the development of myofascial pain syndrome, which may also be associated with gluteal bursitis. Such pain is usually the result of repetitive microtrauma to the muscle during such activities as running on soft surfaces, overuse of exercise equipment, or other repetitive activities that require hip extension ( Fig. 89.1 ). Blunt trauma to the muscle may also incite gluteus maximus myofascial pain syndrome.

Gluteus maximus syndrome usually results from repetitive microtrauma to the muscle during such activities as running on soft surfaces, overuse of exercise equipment, or other repetitive activities that require hip extension.

Myofascial pain syndrome is a chronic pain syndrome that affects a focal or regional portion of the body. The sine qua non of myofascial pain syndrome is the finding of myofascial trigger points on physical examination. Although these trigger points are generally localized to the part of the body affected, the pain is often referred to other areas. This referred pain may be misdiagnosed or attributed to other organ systems, thus leading to extensive evaluation and ineffective treatment. Patients with myofascial pain syndrome involving the gluteus maximus have primary pain in the medial and lower aspects of the muscle that is referred across the buttocks and into the coccygeal area ( Fig. 89.2 ).

Patients with myofascial pain syndrome involving the gluteus maximus have primary pain in the medial and lower aspects of the muscle that is referred across the buttocks and into the coccygeal area.

(From Waldman SD. Gluteus maximus syndrome. In: Atlas of pain management injection techniques . Philadelphia: Saunders; 2007:379.)

The trigger point is the pathognomonic lesion of myofascial pain syndrome and is characterized by a local point of exquisite tenderness in the affected muscle. Mechanical stimulation of the trigger point by palpation or stretching produces not only intense local pain but also referred pain. In addition, involuntary withdrawal of the stimulated muscle, called a jump sign, often occurs and is characteristic of myofascial pain syndrome. Patients with gluteus maximus syndrome have a trigger point over the upper, medial, and lower aspects of the muscle (see Fig. 89.1 ).

Taut bands of muscle fibers are often identified when myofascial trigger points are palpated. Despite this consistent physical finding, the pathophysiology of the myofascial trigger point remains elusive, although trigger points are believed to be caused by microtrauma to the affected muscle. This trauma may result from a single injury, repetitive microtrauma, or chronic deconditioning of the agonist and antagonist muscle unit.

In addition to muscle trauma, various other factors seem to predispose patients to develop myofascial pain syndrome. For instance, a weekend athlete who subjects his or her body to unaccustomed physical activity may develop myofascial pain syndrome. Poor posture while sitting at a computer or while watching television has also been implicated as a predisposing factor. Previous injuries may result in abnormal muscle function and lead to the development of myofascial pain syndrome. All these predisposing factors may be intensified if the patient also suffers from poor nutritional status or coexisting psychological or behavioral abnormalities, including chronic stress and depression. The gluteus maximus muscle seems to be particularly susceptible to stress-induced myofascial pain syndrome.

Stiffness and fatigue often coexist with pain, and they increase the functional disability associated with this disease and complicate its treatment. Myofascial pain syndrome may occur as a primary disease state or in conjunction with other painful conditions, including radiculopathy and chronic regional pain syndromes. Psychological or behavioral abnormalities, including depression, frequently coexist with the muscle abnormalities, and management of these psychological disorders is an integral part of any successful treatment plan.