The short, thick quadratus lumborum (QL) is a wonder of a muscle. While the iliopsoas initiates walking, the quadratus lumborum provides the powerful stability so we can walk. Some researchers believe that complete bilateral paralysis of the quadratus lumborum would make walking impossible, even with braces. This magnificent muscle is an essential component in the bedrock of our bipedal freedom.
The two QLs work as a team, along with the iliopsoas and lumbar paraspinals (multifidi, erector spinae) in stabilizing the lumbar spine. Like the iliopsoas, if this fundamental stabilizer is distressed it can be like a hurricane blowing through with devastating effects. Any movement can be painful, including urination and defecation. The pain may be excruciating in any position that increases weight bearing and requires stabilization of the lumbar spine. Rolling onto either side from a supine position is painful and difficult; coughing and sneezing can be agonizing. In fact, bending forward, twisting, and sneezing or coughing at the same time can throw the quadratus lumborum into spasm. If it’s not a full-blown hurricane, an irritated quadratus lumborum can blow an ill wind of persistent aching pain and gradual loss of lower back and pelvic flexibility, range of motion, and vitality.