The sacroiliac (SI) joint connects the hip bones (ilia) to the triangular bone at the base of the spine (sacrum). This small, strong joint acts as a shock absorber, transferring forces between the upper body and the legs during movement. When the SI joint becomes dysfunctional, it often causes sharp pain in the lower back and pelvis, sometimes radiating into the hip, groin, or thigh. This discomfort leads many people to feel the joint is “shifted” or “stuck.”
SI joint pain is usually caused by abnormal motion—either too much or too little movement—rather than a true dislocation. Addressing this dysfunction requires specific movements designed to restore the joint’s proper function and stabilize the surrounding structure.
Understanding SI Joint Dysfunction
The sensation of the SI joint being “out of place” is a symptom of abnormal motion, not a full dislocation. Dysfunction is categorized into two main types: hypomobility and hypermobility.
Hypomobility, or fixation, occurs when the joint moves too little, often leading to stiffness, muscle tension, and pain localized on one side of the lower back or buttocks. Conversely, hypermobility involves excessive movement, resulting in instability and a feeling that the pelvis might give way. This excessive motion can inflame the joint and surrounding nerves, causing pain in the lower back, hip, and groin.
Both types of dysfunction can lead to pain that mimics sciatica, radiating down the back of the leg. Inflammation of the joint, known as sacroiliitis, can accompany either form, contributing to a dull ache or sharp pain. Causes of SI joint issues include trauma, arthritis, and hormonal changes that increase ligament laxity, such as during pregnancy.
Targeted Stretches for Immediate Relief
When the SI joint feels locked or stuck, gentle, targeted stretching can help restore normal joint mechanics and relieve surrounding muscle tension. These movements mobilize a hypomobile joint or calm muscles spasming around the painful area. Always perform stretches mindfully and stop immediately if any sharp or increasing pain occurs.
Figure-4 Stretch
The Figure-4 stretch (supine piriformis stretch) is effective because the piriformis muscle runs close to the SI joint and often becomes tight. Lie on your back with both knees bent and cross one ankle over the opposite knee. Gently lift the supporting knee toward your chest until a comfortable stretch is felt in the hip and buttock. Holding this position for up to one minute on each side helps release tension contributing to joint compression.
Single Knee-to-Chest Stretch
The single knee-to-chest stretch helps elongate hip muscles and reduce pressure on spinal nerves. While lying on your back, bring one knee toward your chest and grasp it gently with your hands. Hold the stretch for about 30 seconds before slowly returning the leg to the starting position. This movement helps stretch tight hip flexors, which may aid in realigning the pelvis.
Gentle Trunk Rotation
Gentle trunk rotation encourages movement in a stiff SI joint by stretching the core muscles. Lie on your back with your knees bent and feet flat, keeping your shoulders pressed to the floor. Slowly drop your knees to one side, holding for a few seconds before returning to the center and repeating on the other side. These mobilization exercises should encourage a gentle, non-painful release of tightness.
Stabilization Exercises for Long-Term Correction
Long-term correction requires strengthening the muscles that support and stabilize the pelvis. The SI joint relies heavily on the surrounding core and hip muscles, especially the gluteus maximus and deep core muscles, to maintain stability. Strengthening these areas prevents the excessive movement (hypermobility) that often leads to recurring pain.
Glute Bridge
The Glute Bridge strengthens the gluteus maximus and lower back muscles. Lie on your back with knees bent and feet flat, then tighten your buttocks and abdomen before lifting your hips toward the ceiling. Hold the top position for a few seconds, focusing on contracting the glutes, and then slowly lower back down. This movement helps stabilize the core while strengthening the main hip extensor.
Clamshells
Clamshells target the hip abductors and deep hip rotators, which are important for pelvic stabilization. Lie on your side with your knees bent and feet together, then slowly lift the top knee upward, keeping your feet in contact. The movement should be controlled, especially when lowering, to maximize the strength of the stabilizing muscles. Aim for three sets of ten repetitions on each side to build endurance.
Bird-Dog
The Bird-Dog exercise engages the deep core muscles (transverse abdominis) while coordinating opposite limb movements. Start on your hands and knees with a flat back. Simultaneously extend one leg backward and the opposite arm forward, keeping your torso stable. This exercise teaches the core to stabilize the spine and pelvis, preventing rotation and building the functional strength necessary to prevent future SI joint issues.
When Professional Intervention is Required
While self-treatment manages many cases of SI joint pain, certain symptoms require professional medical evaluation. Severe or persistent pain lasting longer than a week, or pain that progressively worsens despite rest, should prompt a consultation with a doctor.
Urgent attention is required for specific warning signs that may suggest a serious underlying spinal condition. These include new or sudden numbness, tingling, or weakness in both legs, or the sudden loss of bowel or bladder control. Such symptoms could indicate cauda equina syndrome, a serious condition involving nerve compression that requires immediate medical intervention. Pain following a recent accident, severe fall, or trauma also warrants professional examination.
If conservative home measures are insufficient, a physical therapist can offer manual adjustments, joint mobilization techniques, and targeted exercise programs. If pain continues to limit progress, a medical doctor may recommend diagnostic and therapeutic SI joint injections. These injections contain an anesthetic and a steroid, which confirms the joint as the source of pain and provides temporary relief from inflammation, allowing the patient to engage more effectively in physical therapy.