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Lumbar quadriceps muscle and back pain
Last reviewed: 04.07.2025
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The square muscle of the lumbar spine - m. quadratus lumborum, when contracted unilaterally, takes part in the tilt of the spine with the rib cage. When tonicly contracted on both sides, it holds the spine in a vertical position. This muscle, pulling the 12th rib, also acts as an exhalation muscle. When the spine and rib cage are fixed and both square muscles of the lumbar spine contract simultaneously, the pelvis is lifted and the spine is flexed in the lumbar region.
- Beginning: Labium internum, Cristae iliacae and Lig. iliolumbale
- Attachment: XII rib, Proc. costarii I - IV lumbar vertebrae.
- Innervation: from the lumbar plexus, muscular branches of the spinal nerves T12-L2
[ Diagnostics
The patient assumes a position in which the 12th rib departs from the iliac crest and the muscle becomes accessible for palpation, being in a moderately tense state. As a rule, only the caudal parts of the fibers can be palpated. The condition of the remaining parts can be assessed only indirectly by the difference in pain during deep palpation.
Referred pain
It can be localized along the iliac crest, sometimes in the area of the adjacent lower quadrant of the abdomen. It can extend to the outer-upper border of the groin. The pain can be localized in the area of the greater trochanter, and the outer-upper parts of the thigh, the area of the sacrolumbar joint, and be reflected in the lower parts of the buttock. In case of bilateral lesions, the pain can extend beyond the sacral region.