The sacroiliac (SI) joint connects the spine and the pelvis, transferring weight and absorbing impact between the upper body and the legs. Dysfunction can lead to stiffness, restricted movement, and significant pain in the lower back and buttocks. This article outlines gentle stretches and targeted exercises to provide temporary relief from SI joint discomfort.
Anatomy and Common Causes of SI Joint Pain
The SI joints are located on either side of the lower spine, linking the triangular sacrum bone to the large ilium bones of the pelvis. Strong ligaments support these joints, limiting motion to a minimal degree to maintain stability during movement. The joint distributes forces generated by standing, walking, and lifting from the trunk to the lower extremities.
SI joint pain often arises from a disruption in normal movement, categorized as hypermobility (too much movement) or hypomobility (too little movement or fixation). Hypermobility results from trauma or ligamentous laxity caused by hormonal changes, particularly during pregnancy. Hypomobility, or stiffness, can be caused by degenerative changes like osteoarthritis, leg-length discrepancies, or altered gait patterns. Pain is often the result of irritation or inflammation of the joint itself (sacroiliitis) or the surrounding ligaments.
Gentle Stretches for Mobilization
Gentle movements mobilize a stiff or “stuck” SI joint, providing temporary relief from fixation. The single knee-to-chest stretch helps to loosen the muscles of the lower back and hip. To perform this, lie on your back with both knees bent, then gently pull one knee toward your chest until a mild stretch is felt. Hold this position for 15 to 30 seconds, keeping the opposite foot flat on the floor, and repeat on the other side.
The trunk rotation stretch promotes flexibility in the spine and torso, indirectly affecting the SI joint. Lie on your back with knees bent and feet flat, extending your arms out to the sides in a ‘T’ shape. Keeping your shoulders pressed against the floor, slowly lower your bent knees to one side until a gentle stretch is felt. Hold for a few seconds before returning to the center and repeating on the opposite side, avoiding sharp, sudden pain.
The Figure-4 stretch, also known as the piriformis stretch, targets the deep muscles of the outer hip that can pull on the SI joint. Lie on your back, cross one ankle over the opposite knee, then gently pull the supporting thigh toward your chest until a stretch is felt in the buttock. Perform these stretches within a comfortable range of motion and immediately stop if the movement causes sharp or radiating pain.
Strengthening Exercises for SI Joint Stability
After mobilization, strengthening the surrounding musculature is important for long-term stability and pain prevention. Weakness in the core and gluteal muscles is a common factor in recurrent SI joint dysfunction, as these muscles maintain pelvic alignment. The glute bridge is an excellent foundation exercise that targets the gluteus maximus and deep abdominal muscles, reducing joint strain.
To perform a bridge, lie on your back with knees bent and feet flat on the floor, hip-width apart. Engage your core and squeeze your glutes to slowly lift your hips until your body forms a straight line from your shoulders to your knees. Hold the position for five to ten seconds, repeating for 10 to 15 repetitions, focusing on controlled movement rather than speed.
The clamshell is a stabilization exercise that strengthens the gluteus medius, a muscle often found to be weak in people with SI joint pain. Lie on your side with knees bent and hips stacked, then, keeping your feet together, slowly lift your top knee toward the ceiling like a clamshell opening. The bird-dog exercise promotes core stability and strengthens the lower back muscles. Start on all fours and slowly extend one arm straight forward while simultaneously extending the opposite leg straight backward, maintaining a neutral spine. If pain persists, worsens, or is accompanied by neurological symptoms like numbness or weakness, a professional evaluation is necessary.