The sacroiliac (SI) joint connects the sacrum to the pelvis. It can become dysfunctional from too much or too little motion/immobility. Pregnancy can also result in sacroiliac joint dysfunction. SI joint dysfunction or inflammation usually results in lower back pain or hip pain. The pain may radiate to the groin area or down the leg.
While pain due to disk herniation or disk bulge can occur in the neck, it is more common in the lower back. Herniated disk pain can occur from physical contact of the disk with a nerve. This can cause numbness and tingling in the arm or the leg and, if severe enough, weakness and even paralysis of the arm or leg. Alternatively, symptoms may be due to inflammation of a nerve from content that has leaked out from the center of the herniated disk, an area known as the nucleus pulposus. This is known as radicular pain.
Disk pain can also occur from a bulging, degenerated intervertebral disk that has not herniated and pressed up against a nerve or leaked any content. The disk space itself is the source of the spine pain in this case. This condition is often referred to as axial pain.
What causes herniated disks and disk pain? These conditions can result from a variety of scenarios including age-related wear and tear or using your back instead of your legs to lift objects, especially when twisting motions are involved.