The quadratus lumborum, or "QL", connects from the 12th rib to the iliac crest (hip bone) and attaches to the sides of the lumbar vertebrae on each side of the spine. A stabilizer of the lumbar spine, the QL supports the entire body and without these imperative muscles, "You'd sway around like a flower on a slender stem." "Besides controlling movement at the waist , the quadratus lumborum muscles also participate in forced exhalation, such as in coughing or sneezing."
- Acting unilaterally: stabilizes the lumbar spine in the upright position; laterally flexes the lumbar spine; acts as a hip hiker.
- Acting bilaterally: extends the lumbar spine; acts in forced exhalation, as may occur in coughing; fixes the 12th rib, facilitating contraction of the diaphragm.
The QL can be so tight that it can "pull a lumbar vertebra or the sacroiliac joint out of place", according to Clair and Amber Davies, The Trigger Point Therapy Workbook. They go on to say, "The pain from quadratus lumborum trigger points is commonly mistaken for arthritis of the spine, disk problems, sciatica, or bursitis in the hip."
- may be unable to bear standing upright or walking due to deep, aching low back pain
- inability to turn over in bed without pain
- trigger points may produce an apparent leg-length discrepancy
- overload stress of simultaneous bending and lifting
- awkward lifting of heavy objects
- sustained and repetitive strain
- sudden leg-length discrepancy or one side of the pelvis being smaller than the other
- falls and auto accidents
Davies, Clair and Amber. The Trigger Point Therapy Workbook: Your Self-Treatment Guide for Pain Relief. Oakland: New Harbinger Publications, Inc., 2004. Print.
Finando, Donna & Finando, Stephen. Trigger Point Therapy for Myofascial Pain: The Practice of Informed Touch. Rochester: Healing Arts Press, 2005. Print.
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"Quadratus Lumborum Trigger Point Diagram." The Trigger Point & Referred Pain Guide, http://www.triggerpoints.net/muscle/quadratus-lumborum