The quadratus lumborum
Quadratus lumborum · musculus quadratus lumborum
A deep, square muscle in the lower back that bends your trunk sideways and steadies the spine.
What it does
The quadratus lumborum runs between the top of the pelvis, the lowest rib and the lumbar vertebrae on each side. It bends the trunk to the side, hitches the hip up when you walk and anchors the lowest rib so the diaphragm can pull against it.
Surprising fact
Because it can lift one side of the pelvis, it is sometimes called the "hip hiker".
Why it matters
It is a common source of deep, one-sided lower back ache, especially after lifting and twisting at the same time.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.