Sacroiliac (SI) joint dysfunction is a common cause of lower back pain. Individuals may also feel pain in different parts of the body below the waist, including the buttocks, hips, groin, legs, and feet. In addition to pain, other kinds of discomfort are common, such as numbness, a pins-and-needles sensation, and a feeling like the knee is buckling. The symptoms of SI joint dysfunction may be felt in one or both legs.
Sleeping through the night can be difficult if the pain flares up when an individual turns over in bed or is sleeping on an affected side. Sitting for extended periods, as in a long car ride, can cause a painful flare, as can standing or walking for a prolonged period. Transitional movements, such as climbing stairs or getting up from a couch, can exacerbate symptoms, often leading to excruciating pain.
Sacroiliac joint dysfunction may or may not lead to sacroiliitis, which is inflammation of the SI joint. Sacroiliitis pain is often felt in the lower back, hips, buttocks, or front of the thigh and back of the leg (one or both). The discomfort is usually located in the area of the inflammation. However, in severe cases, the pain can travel down to the groin, legs, or feet, mimicking sciatica -- the pain felt when the sciatic nerve is compressed or otherwise irritated. A low-grade fever often accompanies sacroiliitis. Stiffness is a common symptom, often experienced when getting out of bed in the morning or after sitting for a long time.
Our Care Team
- Associate Professor of Neurological Surgery, Spinal Surgery
- Co-Director, Spinal Deformity and Scoliosis Program
- Chief of Neurological Surgery, NYP Lower Manhattan
Reviewed by: Louis Chang, MD
Last reviewed/Last updated: April 2021