Anatomy Spotlight: Quadratus Lumborum

The Quadratus Lumborum, also called the QL, is the primary lower back muscle for lumbar stability, flexion and extension, and torso rotation. This is the muscle that becomes tight when repetitive lifting and/or twisting occurs. The QL attaches to the 12th (last, floating) rib, the transverse processes of the lumbar spine, and the crest of the ilium (pelvis). It has three different fiber orientations, which allow it to provide a variety of movements for the lower back. This muscle is deep to the erector spinae muscle group. Trigger points in the QL refer pain along the sacrum in the pelvis or along the outside of the glute tissue and hip. A deep aching pain in the tailbone area or a “bursitis” feeling in the outside of the hip are common.