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Orthopedist

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Square lumbar muscle and back pain

Alexey Portnov, medical expert
Last reviewed: 23.04.2024

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The square muscle of the waist is m. Quadratus lumborum with unilateral contraction takes part in the inclination of the spine with the thorax. With tonic contraction on both sides, it holds the spine in an upright position. This muscle, pulling the XII rib, acts as an exhalation muscle. With the fixation of the spine and chest and with simultaneous contraction of both square muscles of the waist, the pelvis rises and, at the same time, the spinal flexion in the lumbar region.

Beginning: Labium internum, Cristae iliacae and Lig. Iliolumbale
Attachment: XII edge, Proc. Costarii I - IV lumbar vertebrae.
Innervation: from lumbar- | plexus, muscle branches of the spinal nerves T12-L2

trusted-source [1], [2]

Diagnostics

The patient assumes a pose at which the 12th rib moves away from the crest of the aboral bone and the muscle becomes accessible for palpation, being in a moderately stressed state. As a rule, only caudal sections of fibers can be palpated. Evaluate the state of other departments can only indirectly by the extent of soreness with deep palpation.

trusted-source [3], [4], [5], [6]

Reflected pain

Can be localized along the iliac crest, sometimes in the region of the adjacent lower quadrant of the abdomen. It can spread to the outer-upper border of the groin. The pain can be localized in the area of the large trochanter, and the upper and upper thighs, the area of the lumbosacral joint, reflected in the lower parts of the buttock. With bilateral injury, pain can spread beyond the sacral region

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