The Sacroiliac joint is located at the bottom and just to the side of the back. The joint can become inflamed and painful, causing either a sharp pain or an ache in the lower back which can spread to the buttocks. The pain can be caused by a trauatic impact, poor biomechanics, inflammatory disease or from hormonal changes, such as pregnancy.
On this page:
- Symptoms & diagnosis
- Causes & anatomy
Symptoms of SI joint injury
Symptoms of Sacroiliac Joint Pain consist of pain at the bottom of the spine which is located ususally on one side, either to the left or right of the spine, although sometimes is described as a band of pain across the lower back. The pain can range from an ache to a sharp pain which restricts movement. Sacroiliac joint pain may radiate out into your buttocks and low back and will often radiate to the front into the groin and occasionally testicles.
As well as pain or discomfort on and around the joint there occasionally may be referred pain radiating into the lower limbs (sciatica). Classic SI joint pain symptoms also include difficulty turning over in bed, putting on shoes and socks and pain climbing in and out of the car. The patient will experience stiffness in the lower back when getting up after sitting for long periods and when getting up from bed in the morning. There is likely to be aching to one side of your lower back when sitting or driving long distances. There may be tenderness on palpating (pressing in on) the ligaments which surround the joint.
SI joint assessment tests
Other signs typically seen in patients may include leg length differences, a negative 'Stork Test' and Ilia Rotation. Differences in leg length can be a contributing factor to sacroiliac pain and can be measured with a tape measure using bony landmarks on the skeleton as reference points. However, this is not easy as bony landmarks are covered in flesh which can move about when you are trying to use a measuring tape. There is a much better way to check leg length and with a trained eye and practice you can soon learn to do this reasonably well.
Leg length difference test bent knees (play video): The athlete is placed on their back with knees bent and heels together, taking care to ensure the heels and hips are as square as possible. The therapist then looks from the front and side at the knees to assess if they are level or not. If one knee is higher than the other, this could indicate a longer tibia in this leg. One knee forward of the other may indicate a longer femur in that leg. Ensuring the hips are level can be difficult so a further test is needed to give a better picture.
Straight Leg Test: In order to get the hips square the athlete raises the hips off the couch and lowers them down again. This should help ensure they lie in a natural position. The therapist then gently pulls the legs straight and places the thumbs on the ankle bone on the inside (medial malleoli). From here it should be evident if one leg is longer than the other as one thumb will be higher than the other.
Stork test (play video): The athlete stands with their back to the therapist, holding onto something for support. The posterior superior iliac spine (PSIS) and a spinous process exactly horizontal to it are marked with a small cross. The therapist places one thumb on the PSIS and the other thumb on the spinous process opposite. The athlete raises one knee up as high as it will go. If the Sacroiliac joint is functional then the posterior-superior iliac spine will move down under its original position. This means it is allowing the ilia to rotate. This is shown as the therapists thumb (on the PSIS) will move down below the thumb on the spinous process. A dysfunctional SI joint will not allow the ilia to rotate and so the therapists thumb will stay where it is or move up.
Ilia Rotation: With the patient lying on their back a modesty towel is placed over the pelvic area. The towel not only provides the patient with privacy but also prevents the therapists eyes from being distracted by uneven images created by clothing patterns. The therapist stands one side of the couch and must lean over the patient and ensure the dominant eye is looking along the midline of the patient whilst the other eye is closed.
This ensures your angle of view is central and not distorted. The therapist then places one thumb on each ASIS and compares their location by looking along the midline between both ASIS, which should indicate they are level. If one is higher than another this may indicate a pelvic rotation or shunt although bone shapes can vary in individuals and it is common to see differences in ilia shapes between the right and left side. This can lead to confusion regarding diagnosis but it should be remembered that tests are not definitive and are only a method of gathering information to assist with a diagnosis. The more tests you use then the more information you have.
Causes & anatomy
The Sacroiliac joints are located at the very bottom of the back, one either side of the spine and help make up the rear part of the pelvic girdle. They sit between the sacrum bone and the Ilia or hip bones. SIJ dysfunction is a term which is commonly used when talking about sacroiliac injuries. This dysfunction refers to either hypo or hypermobility (low or high respectively). In other words, the joint can become 'locked' or be too mobile. This can then lead to problems with surrounding structures such as ligaments (e.g. Iliolumbar ligament) and muscles, which means SIJ problems can cause a wide range of symptoms throughout the lower back and buttocks, or even the thigh or groin.
The function of the SI joints is to allow torsional or twisting movements when we move our legs. The legs act like long levers and without the sacroiliac joints and the pubic symphesis (at the front of the pelvis) which allow these small movements, the pelvis would be at higher risk of a fracture.
The concept of the SIJ causing lower back pain is now pretty well understood. However, due to the complex anatomy and movement patterns at the joints and area in general, evaluation and treatment of sacroiliac dysfunctions is still controversial.
Causes of Sacroiliac joint pain can be split into four categories; traumatic, biomechanical, hormonal and inflammatory joint disease.
Traumatic injuries to the SIJ are caused when there is a sudden impact which 'jolts' the joint. A common example is landing on the buttocks. This kind of injury usually causes damage to the ligaments which support the joint.
Biomechanical - Pain due to biomechanical injuries will usually come on over a period of time and often with increased activity or a change in occupation/sport etc. The most common biomechanical problems include leg length discrepancy, over pronation, twisted pelvis and muscle imbalances
Hormonal changes, most notably during pregnancy can cause sacroiliac pain. In preparation for giving birth, the ligaments of the pelvis especially increase in laxity. Combining this with an increase in weight putting extra strain on the spine, may lead to mechanical changes which can result in pain.
Inflammatory Joint Disease - Spondyloarthropathies are inflammatory conditions which affect the spine. These include Ankylosing Spondylitis which is the most common inflammatory condition to cause SI joint pain.
Treatment of sacroiliac joint pain
What can the athlete do?
Rest from any activities which cause pain, particularly running. Wearing a sacroiliac support belt which may help take the strain off the joint and provide relief from symptoms. It works by applying compression around the hip and across the joint, protecting it from further injury.
If muscle spasm around the area is suspected use a heat pack to help them relax. Sports massage may also help reduce muscle tension. Don't heat if acute inflammation of the joint is suspected though as this will make the condition worse. In this case, cold therapy may be more effective.
What can a sports injury professional do?
A doctor may prescribe anti-inflammatory medications such as ibuprofen which can help reduce inflammation and relax muscles.
A therapist who specializes in back conditions can do a full assessment and diagnostic tests to discover the cause of the problem ruling out medical diseases such as Ankylosing Spondylitis. Electrotherapy such as ultrasound or interferential may be used to treat soft tissues and if indicated and safe to do, level the pelvis via sacroiliac joint manipulation and mobilization. Sports massage may help relieve any soft tissue tension in the area.
Mobilisations are techniques used by professionals such as physiotherapists, chiropractors and osteopaths to help promote fluid movement at a joint. Due to the specialist knowledge required and room for error, these techniques should not be attempted by anyone who is not suitably qualified.
Rolled up towel technique
- Using 2 rolled up towels placed correctly under the pelvis, it is possible to encourage the offending rotated ilia to return to its correct position.
- The patient should be lying in the prone position with one towel located under the Anterior Superior Iliac Spine (ASIS) and the other towel lower down under the opposite Anterior Inferior Iliac Spine (AIIS), which are bony landmarks on the Ilia.
- The patients body weight will encourage the ilias to rotate and if this is accompanied by soft tissue massage work to the low back and gluteal muscles this will further encourage rotated correction.
- In order to place the towels in the correct position the correct diagnosis has to be made. The wrong diagnosis will make things worse.
Articulating the SIJ
- The therapist places one hand under the patient located across the sacrum and ilia joint. This is in preparation to feel the quality of movement between the 2 bones.
- Using the leg as a lever the knee can be gently rotated round in circles to mobilize the SI joint.
- In order to engage the joint you may have to use more hip flexion and an element of compression whilst rotating the limb.
- Movement can be detected with your hand across the joint whilst mobilization occurs. This should continue until quality of movement is detected across the SI Joint.
Straight leg mobilisation
- With the leg straight, the therapist uses their bodyweight to mobilize the leg forwards and backwards.
- This helps to improve mobility of the sacroiliac joint.
Expert interview (play video): Dr Maria Madge explains how a Chiropractor might approach Sacroiliac joint pain.
The aim of exercises for treating Sacroiliac joint pain (play video) is to correct and muscle imbalances. This is likely to include pilates exercises which may help strengthen the core muscles of the trunk. If the above treatment fails, a Corticosteroid injection into the SIJ may be used. Stretching exercises for the muscles of the hip, particularly the hip abductors (on the outside) and gluteal muscles can help if done gently, however, too much stretching with a hypermobile joint can inflame the joint and increase pain.