Effects of Weighted and Elastic Resistance Training of Gluteus Maximus in Sacroiliac Joint Dysfunction

Sacroiliac joint dysfunction or sacroiliitis are common terms used to describe the pain of the sacroiliac joint. It is usually caused by abnormal motion (i.e. hyper- or hypo-mobile) or mal-alignment of the sacroiliac joint. Sacroiliac joint (SI) dysfunction is a well-documented clinical entity that can cause pain and loss of function, The sacroiliac joint (SIJ) has been implicated as the primary pain source in 10% to 25% of the patients with low back pain. During pregnancy, 20% to 80% of the women experience low back or posterior pelvic pain frequently arising from the SIJ.

The Gluteus maximus is inserted proximally into the sacrum, the dorsal sacral ligaments, the posterior portion of the crest of the ilium, and the sacrotuberous ligament. The muscle fibers run inferiorly and laterally to the distal insertion, where it splits into two components. The upper half of the muscle inserts into the iliotibial tract of the fascia and the lower half into the gluteal tuberosity of the femur. Due to its attachments, the gluteus maximus is primarily involved in hip extension and lateral rotation.

Fischer \& Houtz found in electromyography (EMG) study that the strongest contractions of gluteus maximus occurred with muscle setting by isometric contraction, external rotation, abduction with resistance, and vigorous hyperextension exercises of the thigh and trunk in an erect posture. Weakness of gluteal muscles causes decreased sacroiliac (SI) joint stability in patients with sacroiliac disorders. gluteus maximus muscle, due to its attachments to the sacrum, iliac bones, and sacrotuberous ligament, plays a significant role in the stability of the SI joint. The stabilizing forces applied to the SI joint, therefore, could be compromised with gluteal muscle weakness. In patients with gluteal weakness, shortening of the hamstring muscles, through their common attachments to the ischial tuberosity and sacrotuberous ligament, could compensate for gluteal muscle weakness and contribute to the SI joint stability.

A relationship between the gluteus maximus and the SI joint has been investigated in particular. Anatomical studies suggest that the gluteus maximus, with muscle fibers perpendicular to the joint surfaces, can help to stabilize the SI joint. Furthermore, it was discovered that activating the gluteus maximus increased compressive force across the SI joint. Individuals with SI joint dysfunction have abnormal gluteus maximus recruitment during weight-bearing exercises. As a result, it is hypothesized that gluteus maximus weakness can be linked to incorrect loading of the SI joint and be a cause of the impairments associated with SI joint dysfunction.

Hip extension exercise is the general clinical method for improving the weakened muscle strength of the hip extensors. These exercises are often used to strengthen the gluteus maximus and is also recommended for patients with pain in the lower back, pelvis, or hip. The gluteus maximus contributes to the postural alignments, core stability, and functional abilities that are important for normal gait. A weakness of the gluteus maximus can cause an abnormal gait cycle that can affect the gait mechanics at both hip and knee joints. In particular, gluteus maximus exercise is important for patients who have low back pain and lower extremity injuries. Patients with low back pain show reduced activity of the gluteus maximus. Early activation of the hamstring muscles and spinal erector, as well as delayed or decreased activation of the gluteal muscles, are considered indications of faulty muscle activation.

Studies have assessed methods for selective strengthening of the gluteus maximus. Prone hip extension (PHE) exercise is generally used to activate and strengthen the gluteus maximus selectively. Active prone hip extension with knee flexion is a common exercise employed to optimize gluteus maximus activation because this position causes active insufficiency of the hamstring. A previous study reported that PHE exercise is the most effective method for activating the gluteal muscles when subjects extend their hip with 30° abduction. Other studies have suggested that an abdominal drawing-in maneuver (ADIM) with prone hip extension is useful for the selective activation of the gluteus maximus from the erector spinae and hamstring.

A correction of the abnormal pattern is recommended to reduce the stress on the spine and hip joint. In a clinical setting, the ADIM is used during hip extension to prevent abnormal motion of the pelvis and lumbar., and the degree of knee extension affects the gluteus maximus activity. When the level of knee extension is increased, the activity of the gluteus maximus decreases, and the hamstring activity increases. Previous studies compared the muscle activities of the hamstring and gluteus maximus during prone hip extension with ADIM. The following were applied during active prone hip extension exercises: knee flexion, knee extension, hip external rotation with knee flexion, and hip external rotation with knee extension. In addition, eleven different exercises of the gluteus maximus used in therapeutic exercises were compared.

Although a wide variety of different exercises are advocated train and condition gluteus maximus and surrounding musculature, there are no specific guidelines for gluteus maximus strengthening with SI joint dysfunction using best evidence-based practice. This study aims to find out whether the weighted and elastic resistance training of gluteus maximus provides better results in subjects with SIJ dysfunction.