Low back pain is a common health complaint among adults, and the risk of lower back pain increases as you get older. It’s estimated that roughly 25 percentTrusted Source of lower back pain cases are caused by irritation to the sacroiliac (SI) joint. In some cases, stretching may help alleviate SI joint pain by loosening tight muscles that put extra stress on these joints. Tight muscles around your back, hips, buttocks, thigh, and core can all potentially contribute to SI joint discomfort.
Source: healthline