What is the Quadratus Lumborum?

What is the QL? Is it that little square box with the strange designs inside? No that would be a QR code.

The QL is short for Quadratus Lumborum. The quadratus lumborum is a muscle of the posterior abdominal wall. It is the deepest abdominal muscle and commonly referred to as a back muscle. It is irregular and quadrilateral in shape and broader below than above. There are many cases of low back pain(Lumbalgia) and some are due to tension in the QL muscle

The QL is attached to the spinous processes along the lumbar spine L1-L5 and forms a box in between its attachment to the twelfth rib and the iliac crest or top of the hip bone (picture)?
The QL plays an integral role as one of the key muscles that support our vertical posture. It also forms a cushion for our kidneys.
The QL is bilateral on either side of the spine. In many instances, if one side is dysfunctional it can cause a spasm on the opposite side
With bilateral contraction, the QL provides vertical postural support and extends the vertebral column. If the erector spinae muscles are weak it puts more pressure on the QL.
Since the QL has an attachment on the 12th rib it also plays a large role in our respiration while assisting in our inhalation and forced expiration. Many people with chronic respiratory disorders can develop tension in the QL.

The Ql also assists our lateral flexion and rotation of the vertebrae. In short our bending and twisting muscles. If you have done excess raking, shoveling, bending, moving and lifting boxes chances are you have aggravated your QL muscle. 
The QL does a lot of work and affects many corresponding muscles when not performing correctly.

Don’t suffer needlessly. If you are in pain, please come in for a clinical evaluation. We can diagnose the problem and develop a treatment plan for the QL or many other conditions. Feel free to call anytime with your questions or comments.