The sacro-iliac joint (SI joint or SIJ) is between the sacrum, the triangular bone at the base of the spine and the ilium bones of the pelvis. During movement the SIJ helps distribute the body’s weight from the trunk to the pelvis and extremities while protecting the spine, acting as shock absorption.
Anatomy: The SI joints, covered by cartilage, are only capable of a small amount of movement. Their stability is maintained mostly by very strong ligaments connecting the sacrum and ilium inside and outside the joints. The male and female pelvis are different shapes and the SI joints are also slightly different. The SI ligaments loosen during pregnancy due to the hormone relaxin, which allows the pelvic bones to widen during the birthing process.
Symptoms: SIJ pain can be sharp or dull, starting at the SI joint (the dimple) and can move to the buttocks, thighs, groins or up the back. Low back pain is common as well as buttock pain on one of both sides. Sometimes standing up triggers the pain and it may be worse in the morning, easing during the day. SIJ pain can be felt in the hip and needs to be differentiated from hip joint pain. Pain can be aggravated by bending over or by standing up after sitting for a long time; laying down can ease it.
Causes: Trauma such as a direct fall on the buttocks, rear-end of broad-side type car accidents, stepping from an unexpected height, repeated stress injuries such as jogging, muscle imbalance, uneven leg length or after lumbar fusion surgery. The joints become inflamed (sacroiliitis) in Ankylosing spondylitis causing pain in the low back and buttocks; also in Polyarthritis. Hormonal changes can affect the SIJ, particularly during pregnancy and lactation. SIJ pain that occurs for no apparent reason is called idiopathic.
Diagnosis: You will need to see your doctor if you have sudden numbness or tingling in lower back and hips, weakness or numbness in legs, sudden increase in pain, if your recovery is slower than expected or if you have a fever. The doctor will move your legs and hips in different positions to help diagnose SIJ dysfunction. X-rays, injections, MRI or a CT scan may be required as well as blood tests to help diagnose the cause.
Treatment: Ice packs, analgesia and rest in acute stages, spinal manipulation, pelvic stabilisation exercises, wearing a support brace. More invasive treatments include injections into the joint and ligaments, radiofrequency neurotomy or ablation, a minimally invasive surgical procedure using heat from radio waves to destroy the nerves carrying pain to SIJ, cryotherapy, or surgery to fuse the SIJ.
Osteopathic/Manual Management: From an Osteopathic perspective, SIJ pain can sometimes be related to and referred from issues in other areas of the pelvis and low back. Take a detailed case history to understand the nature of the problem and surrounding issues. Examine the pelvis, back and legs and all surrounding tissues; muscles, ligaments, nerves, fascia, etc., for movement, strength and functionality and assess nerve pathways. Perform orthopaedic and neurological tests and determine the root cause. Treat to reduce tension, nerve irritation and pain. Advice regarding exercise and stretching of back, buttocks and legs. Treatment may include manipulation, deep soft tissue massage, trigger point therapy, muscle energy techniques, fascial techniques, dry needling, etc.
We are happy to advise you on your health matters and offer a free 15 minute joint and spinal check, without obligation.
Lin Bridgeford DO KFRP MICAK MICRA FSCCO MSc
Registered Osteopath & Kinesiologist & Yoga Teacher
Aether Bios Clinic
Tel: 01273 309557
Mob: 07710 227038