Breaking down quadratus lumborum
Let’s help you understand the basics of the quadratus lumborum muscle. We’ll cover where it attaches (its origin and insertion), as well as how and when it contracts (its action).
- The word “quadratus” refers to the fact that the muscle has what looks like four distinct sides.
- Lumborum refers to an area of the body, the lumbar area of the spine in particular.
- Quadratus lumborum is often abbreviated as “QL”
Quadratus lumborum attachments
- The QL attaches to the iliac crest. More specifically, it attaches to the top and back part of the pelvis. (Remember, the bone at the top and back of the pelvis is called the ilium.)
- QL also attaches to the transverse processes of the lumbar vertebrae. It usually attaches to just the top four lumbar vertebrae. Remember that the transverse processes are the bony parts that stick out to the side of each vertebra.
- Finally, QL also attaches to the 12th rib. The 12th rib is the last (lowest) rib. It’s also known as a floating rib because it does not attach to the rib cage.
Quadratus lumborum actions
This muscle has three potential actions:
- It extends the spine as in shalabasana.
- QL contracts to bring the ribs closer to the pelvis on the same side, which is known as lateral flexion
- The QL can lift the pelvis toward the lower ribs on the same side. It’s often referred to as the “hip hiker” for that reason.
Which postures cause this muscle to contract?
Which postures lengthen this muscle?
Common problems and additional information
This muscle is often associated with back pain, SI joint pain, and can be part of a larger pattern of anatomical dysfunction. I have already written a more detailed article about this muscle. It can also be part of a larger pattern in the psoas and gluteal relationship.
I often associate muscles in this area as part of the “splinting” response from the body when a spinal disc between the vertebrae bulges or herniates. Muscles in the surrounding area tighten or “splint” to protect and prevent further movement in the area.