Lower back pain that sits deeper in the buttock on one side and gets worse when you stand up from a chair, climb stairs or roll over in bed - many people hear from friends that their "sacroiliac joint is locked" and needs to be "unlocked". There is no shortage of online videos showing how to do it yourself. In this article we explain what the sacroiliac joint is, what symptoms may be related to it, what they are easily confused with, why it is not worth trying to "unlock" the joint yourself, who makes the diagnosis and how to take care of yourself day to day. This is an informational text - you will not find manipulation instructions here, because such things should not be done without a specialist.
This article is for informational purposes only and does not replace medical advice. If you have symptoms, consult a doctor.
What is the sacroiliac joint?
The sacroiliac joint connects the sacrum (the lower, triangular part of the spine) with the iliac bones of the pelvis. We have two of these joints - one on the left and one on the right. They lie roughly beneath the "dimples" visible above the buttocks in many people.
It is a very strong and stable joint. The joint surfaces are uneven and fit into each other, and the whole structure is reinforced by strong ligaments. This allows the joint to transfer the weight of the torso to the pelvis and legs when standing, walking or running. The sacroiliac joint has very little mobility - we are talking about shifts of millimeters and a few degrees. That is exactly why the idea that the joint "popped out" and needs to be "pushed back in" is a major oversimplification.
What affects how the joint works?
- Ligaments - the main factor stabilizing the joint.
- Muscles - the glutes, abdominal muscles, back extensors and pelvic floor muscles affect how the pelvis is loaded.
- Hormones - during pregnancy, hormonal changes make the ligaments more pliable as the pelvis prepares for childbirth.
- The way you move - asymmetry, a leg length difference, hip or foot problems can change how the load is distributed.
What symptoms can the sacroiliac joint cause?
Doctors often describe complaints related to the sacroiliac joint as sacroiliac joint pain or sacroiliac joint dysfunction. They typically include:
- pain in the lower back below the belt line, usually on one side, around the "dimple" above the buttock,
- pain in the buttock, sometimes radiating to the back or side of the thigh, less often to the groin,
- pain that gets worse when changing position - standing up from a chair, getting out of a car, rolling over in bed,
- discomfort when standing on one leg, climbing stairs or walking for longer periods,
- pain when sitting on one buttock for a long time or sleeping on your side,
- sometimes a feeling of "instability" or "clicking" around the pelvis.
What can sacroiliac joint pain be confused with?
The same areas hurt with many other problems. That is why a self-"diagnosis" is practically impossible.
| Possible source of pain | What may set it apart |
|---|---|
| Sacroiliac joint | One-sided pain below the belt line, around the "dimple", worse when changing position and standing on one leg |
| Lumbar spine | Pain more often higher up, along the spine, depending on bending forward and backward |
| Nerve root compression (sciatica) | Pain running below the knee, tingling, numbness, leg weakness |
| Hip joint | Pain more often in the groin, difficulty putting on shoes and socks, limited hip rotation |
| Trochanteric bursitis | Pain on the side of the hip, tenderness when pressing there, pain when lying on that side |
| Inflammatory diseases of the spinal joints | Pain usually in younger people, long morning stiffness, improvement with movement, pain in the second half of the night |
We describe pain radiating to the leg in our article on sciatica, and possible causes of pain around the hip in the text about hip pain.
Why can sacroiliac joint problems occur?
The most commonly mentioned factors include:
- pregnancy and the postpartum period - hormonal changes, weight gain and a change in posture,
- a fall onto the buttock or another pelvic injury,
- repetitive, one-sided loads, e.g. in some sports,
- a leg length difference, changes in the hip joints or feet,
- degenerative changes, more common with age,
- inflammatory diseases - inflammation of the sacroiliac joints is sometimes one of the first symptoms of spondyloarthropathy, e.g. ankylosing spondylitis,
- a history of lumbar spine surgery.
Often it is impossible to point to a single cause, and the pain has several sources at once.
Can you unlock the sacroiliac joint yourself?
The short answer: it is not worth doing. Here is why.
- You don't know exactly what hurts. As the table above shows, pain in this area can come from the spine, a nerve, the hip, a bursa or even the pelvic organs. "Unlocking" a joint that is not the source of the pain explains nothing and may delay a proper diagnosis.
- "Locked" is largely a colloquial term. The sacroiliac joint moves within a very small range. The characteristic "click" during manipulation does not mean that something has gone back into place.
- You may miss a serious cause. Pain in this area can be a symptom of inflammation, a stress fracture, an infection or gynecological or urological problems. These situations require treatment, not "realignment".
- Sudden twists and thrusts can make symptoms worse, especially with osteoporosis, during pregnancy, after an injury or with spinal changes.
If someone offers to "realign your pelvis" without an examination and a conversation about your symptoms, that is a warning sign. Manual techniques can be part of therapy, but a specialist decides on them after an assessment, not a video online.
What about pelvic pain during pregnancy and after childbirth?
Discomfort around the sacroiliac joints and the pubic symphysis is common during pregnancy. Hormonal changes make the pelvic ligaments more pliable, and the growing belly shifts the center of gravity and changes posture. Many women then feel pain in the buttock, the lower back or the front of the pelvis, especially when climbing stairs, rolling over in bed or standing on one leg.
During this period you should especially avoid self-manipulation and sudden "unlocking" exercises. Discuss every new symptom with the doctor overseeing your pregnancy, who can refer you to a physical therapist working with pregnant women if needed. Pelvic or back pain with bleeding, contractions, fever, fluid leakage or reduced baby movements requires urgent assessment. After childbirth the symptoms often gradually subside, but if they persist or make caring for your baby difficult, it is worth going back to your doctor.
Who diagnoses sacroiliac joint pain?
The first step is usually a family doctor. Depending on the symptoms, they may refer you to an orthopedist, a rheumatologist (if an inflammatory disease is suspected), a neurologist (with nerve-related symptoms) or for physical therapy. Pregnant women and new mothers should discuss their symptoms with the doctor overseeing the pregnancy.
What does the diagnostic process look like?
- Medical history - where exactly it hurts, since when, what makes the pain worse, whether there was a pregnancy or injury, whether there is morning stiffness, fever or symptoms from other organs.
- Examination - assessment of posture, gait, spine and hip mobility, strength, sensation and reflexes, plus a set of provocation tests for the sacroiliac joint. A single test says little; what matters is several tests together.
- Imaging - pelvic X-ray, MRI (especially when inflammation is suspected), sometimes CT. A doctor orders them when there are indications.
- Blood tests - e.g. inflammatory markers, sometimes tests for rheumatic diseases.
- Diagnostic block - in selected cases a specialist injects an anesthetic into the joint under imaging guidance to check whether it is the source of the pain.
The treatment plan depends on the cause and is set by a doctor, while exercises are selected by a physical therapist after an examination.
When does pain in the sacral and buttock area require urgent help?
Go to the emergency room or call 112 immediately if you experience:
- numbness in the groin, buttocks or inner thighs,
- problems urinating, urinary or fecal incontinence,
- rapidly increasing weakness in one or both legs,
- severe pain after a fall or accident, especially in an older person or someone with osteoporosis.
An urgent doctor's visit is needed when the pain is accompanied by fever, unexplained weight loss or a history of cancer, when it gets worse at night and does not depend on position, and also with pain during pregnancy combined with bleeding, contractions or fever.
How to take care of yourself day to day?
Daily habits will not replace a diagnosis, but they can help keep the pelvis from being overloaded unnecessarily. General rules worth discussing with a doctor or physical therapist:
| Situation | What to pay attention to |
|---|---|
| Sitting | Sit on both buttocks, don't cross your legs for long periods, take breaks to move |
| Getting out of bed | Roll onto your side, bend your knees, lower your legs and push up with your arms |
| Getting into a car | Sit down sideways, then turn, moving both legs at the same time |
| Sleep | On your side with a pillow between your knees - many people find this position comfortable |
| Standing | Distribute your weight on both legs, don't "hang" on one hip |
| Movement | Regular walks and general exercise within a pain-free range |
Exercises strengthening the glutes, abdominal and core muscles often appear in physical therapy programs for problems in this area, but specific exercises are selected by a physical therapist after an examination. We describe general rules for taking care of the lower spine in our article on the lumbar spine, and gentle stretching exercises in the text on stretching the lower back. Do every exercise without pain and stop if your symptoms get worse.
Frequently asked questions
Where does the sacroiliac joint hurt?
Usually in the lower back below the belt line, on one side, around the "dimple" above the buttock. The pain may radiate to the buttock and the back of the thigh, less often to the groin.
Can the sacroiliac joint get locked?
"Locked" is a colloquial term. The sacroiliac joint moves within a very small range, and symptoms in this area can have many causes. The assessment should be done by a doctor or physical therapist.
Can you unlock the sacroiliac joint yourself?
We do not recommend it. Without an examination it is unknown what the source of the pain is, and self-manipulation may delay the diagnosis of a more serious cause or make symptoms worse.
What kind of doctor treats the sacroiliac joint?
To start with, a family doctor, who can refer you to an orthopedist, rheumatologist, neurologist or for physical therapy - depending on your symptoms.
Is sacroiliac joint pain common during pregnancy?
Pelvic discomfort during pregnancy is common, partly due to hormonal changes and changes in posture. It is worth discussing every new symptom with the doctor overseeing your pregnancy.
How do you tell sacroiliac joint pain from sciatica?
With sciatica, the pain usually runs below the knee and may be accompanied by numbness or leg weakness. Sacroiliac joint pain more often affects the buttock and thigh. A reliable distinction requires an examination by a doctor.
What tests are done for sacroiliac joint pain?
The basis is a medical history and an examination with provocation tests. Depending on the symptoms, a doctor may order a pelvic X-ray or MRI, blood tests and, in selected cases, a diagnostic block.
Useful resources
- Sciatica - symptoms, causes and situations requiring urgent medical help.
- Hip pain - possible causes, red flags and the diagnostic process.
- Lumbar spine - sitting, lifting, sleep and everyday movement.
- Teeter Core Restore - a PVC rubber wedge cushion for sitting with lumbar support, active sitting and balance exercises.
