The gluteus medius is located in the hip and buttocks. It can contribute to pain in the low back, hip, buttock, and down the outside of the upper leg.
The serratus posterior inferior muscle contributes to pain in the lower back between the bottom of the ribs and the top of the hip. Pain is increased when you twist the torso, bend over, and stretch to reach overhead.
The quadratus lumborum muscle is known for sharp pain in the lower back and aching hip pain. Contributes to pain in the buttocks, groin and abdominal areas.
The iliopsoas muscles can contribute to lower back, abdomen, groin, upper leg, and pelvic pain. Standing from a sitting position is painful.