of the ilium so you must be careful in the description of these as isolated motions. Sacral extension (or counter-nutation). The sacroiliac joints like all spinal joints (except the atlanto-axial) are bicondylar joints, meaning that movement of one side corresponds to a correlative movement of the other side. Clinical significance Inflammation and dysfunction Sacroiliitis refers to inflammation of one or both sacroiliac joints, and is one cause of low back pain. With sacroiliitis, the individual may experience pain in the low back, buttock or thigh, depending on the amount of inflammation. Common mechanical problems of the sacroiliac joint are often called sacroiliac joint dysfunction (also termed SI joint dysfunction; SIJD). Sacroiliac joint dysfunction generally refers to pain in the sacroiliac joint region that is caused by abnormal motion in the sacroiliac joint—either too much or too little motion. It typically results in inflammation of the SI joint, or sacroiliitis. Signs and symptoms The following are signs and symptoms that may be associated with an SI joint (SIJ) problem: Mechanical SIJ dysfunction usually causes a dull unilateral low back pain. The pain is often a mild to moderate ache around the dimple or posterior superior iliac spine (PSIS) region. The pain may become worse and sharp while doing activities such as standing up from a seated position or lifting the knee towards the chest during stair climbing. Pain is typically on one side or the other (unilateral PSIS pain), but the pain can occasionally be bilateral. When the pain of SIJ dysfunction is severe (which is infrequent), there can be referred pain into the hip, groin, and occasionally down the leg, but rarely does the pain radiate below the knee. Pain can be referred from the SIJ down into the buttock or back of the thigh, and rarely to the foot. Low back pain and stiffness, often unilateral, that often increases with prolonged sitting or prolonged walking. Pain may occur during sexual intercourse; however, this is not specific to just sacroiliac joint problems. Sacroiliac joint dysfunction is tested using provocative and nonprovocative maneuvers. Nonprovocative sacroiliac joint examination maneuvers would include Gillet Test, prone knee flexion test, supine long sitting test, standing flexion test, and seated flexion test. There is a lack of evidence that these sacroiliac joint mobility maneuvers detect motion abnormalities. Given the inherent technical limitations of the visible and palpable signs from these sacroiliac joint mobility maneuvers another broad