Quadratus Lumborum - Muscle Physiology & Functional Anatomy
Transverse processes of the upper 4 lumbar vertebrae & the lower border of
12th (last) rib
Lumbar nerves L1-L4
Subcostal nerve (T12)
More Images of the Quadratus Lumborum Muscle
More Information about the Quadratus Lumborum Muscle
The quadratus lumborum muscle is
one of the important deep muscles in the lubmo-pelvic hip complex. In
addition to its 2 concentric functions stated above the quadratus lumborum fixes
the 12th rib during forced expiration and evetates the ilium during an
ipsilateral (on the same side) contraction.
Since the quadratus lumborum connects the pelvis to the spine it is a common
source of low back pain for a variety of reasons including increasing the
propensity for strains to the the erector spinae muscles as well as having
spasms in the quadratus lumborum muscle itself due to overuse.