A cause of pain in the buttocks and occasionally sciatica from an imbalance in a muscle called the piriformis. This must be distinguished from a herniated disc for proper treatment.

Simply put, a spondylolisthesis, or spondy as it’s called in medical circles, is a forward slippage of one vertebra on another. It’s mostly caused by a genetic defect in the pars (a small bone connecting the front of the spine to the back), and in the elderly degenerative disc disease often allows the vertebrae to slip forward.