There are a number of lower back muscles that can cause back pain. One important though often ignored muscle to consider as a potential cause of pain is the quadratus lumborum (QL).
The quadratus lumborum muscles extend from the lowest rib to the crest of the hip bone on each side of the body. It has three types of fibers: ones that run from the rib to the hip bone, ones that run from the rib to the 4 top lumbar vertebrae and ones that run from those vertebrae to the hip bone.
The QL is a spinal stabilizer muscle; it lends stability to the lumbar spine upon movement. The QL is also responsible for side-bending, raising the hip and, when both are contract, extending the spine (bending back). The QL can be a source of back pain when it becomes chronically tight and develops trigger points.
A few different situations can cause QL dysfunction. One is how we move and use our bodies. If you habitually perform an activity that involves raising one hip, you likely have a shortened QL muscle on that side. Such activities include carrying a child on the hip or sitting cross-legged. When a muscle is habitually shortened, the brain learns this association and begins to automatically send signals to tense the muscles after a while (this is what people call “muscle memory”). QL tension can cause lateral pelvic tilt.
Another reason that the QL muscle may become chronically tense is through overuse. Modern day life entails long periods of sitting for most people, whether it’s in a classroom or an office. Most people don’t have perfect posture or strong, balanced core muscles. The erector spinae muscles, the large muscles that lay over the QLs and are supposed to support the weight of the upper body, are often weak. This means that part of the load is placed on the QL muscles, which aren’t designed to bear so much weight. The muscles may fatigue, spasm and become chronically tense.
There are two different types of problems that shortened muscles can cause. One is biomechanical. A short, tense muscle can cause a host of difficulties when the body attempts to move. Other muscles must compensate for the injured muscle, which can lead to shortening of surrounding muscles. Also, a tight QL will pull upward on the hip, often causing lateral pelvic tilt. Since the pelvis is the base of the spine, this change in alignment will affect the whole upper body. The sacroiliac joint, which connects the sacrum to the hip bone, may suffer strain. Vertebral angles change as the pelvis tilts upward on one side, which puts discs and joints at risk for uneven and premature wear.
Another issue involving shortened muscles is the development of trigger points. These are knots that develop in tight bands of muscle fiber and the surrounding connective tissue called myofascia. Trigger points are isolated spasms of fibers, starved of nutrients due to a lack of relaxation. Trigger points often cause localized pain and tenderness, but may also refer pain to other parts of the body. QL trigger points have been known to refer pain to the groin, hip and buttocks.
If you have lower back pain, it important to consider the QL muscle as a potential cause. Ask yourself: Do I perform an activity that involves raising one hip often? Do I have deep muscular pain accompanies by sciatica-like symptoms? Is my pelvis higher on one side than the other? If you answer yes to these questions, it is a good idea to see a physical therapist and a trigger point or myofascial specialist. Self-myofascial release can be pursued with a foam roller or other dense object. See www.youtube.com to get an idea of how to roll your QL out. If you have trigger points, you’ll feel tender spots along the muscle when you roll. Hold steady with the roller’s pressure on the tender spot for 30-45 seconds.
Being aware of the many possible back pain causes will help you find an accurate diagnosis for your pain. Effective back pain treatment and prevention begin with education.