Most women face this problem after age of 40-45 years. This occurs mainly due weak pelvic floor muscles (muscles that support your pelvis) this causing instability at the sacroiliac joint (joint at the backside of the pelvis). This instability cause nerve compression at that level. It’s also called as sciatica. This cause pain in the buttocks and backside of legs. Weakened muscles need exercise so that they can support the pelvis and bring stability.