Iliocostalis Lumborum: Pain Pattern and Treatment
The iliocostalis lumborum is the outer column of the erector spinae in the low back, running from the pelvis up to the lower ribs. It is the muscle you feel bulge beside the spine when you arch. Its documented pattern is low back pain on one side that spreads down into the mid-buttock, and at times forward into the lower abdomen. In an emergency department series, trigger points in this muscle reproduced pain that patients had come in believing was abdominal. This is a sub-page of the erector spinae group page.
Attachments and action
Origin: The back of the sacrum, the posterior iliac crest, and the lumbar spinous processes, through the common erector tendon.
Insertion: The angles of the lower six or seven ribs.
Action: Extension of the spine; with one side working, side-bending toward that side; it also helps hold the rib cage down in forced breathing out.
Where the pain is felt: The low back on one side, beside the spine. The middle of the buttock on the same side. Sometimes the lower abdomen on that side.
Common causes: Lifting and twisting; a long stretch bent to one side, as carrying a child on one hip; sitting on a wallet; a leg-length difference; a fall; a coughing illness that worked the muscle for days.
Patients say: "Low back and buttock, same side, always together." "Bending to the other side pulls it." A lower belly ache on one side that the scans did not explain.
When to get evaluated: Low back pain with numbness or weakness in the leg, changes in bladder or bowel control, fever, blood in the urine, or pain that does not ease with any position needs medical evaluation before anything else. Lower abdominal pain with fever, vomiting, or tenderness to a light touch needs medical evaluation first.
How this muscle is examined and treated
Examination tests side-bending to each side, presses the outer column of the low back for the point that reproduces the buttock pain, and asks about the abdomen. Needling here addresses the muscle over the low back beside the spine. Assessment and treatment happen in the same visit.
Related conditions
Low Back PainHip & Glute PainChronic Pain Patterns
This page is educational. It describes muscle referral patterns commonly associated with pain; it does not diagnose your condition. Individual patterns vary. For evaluation of your specific pain, see a licensed clinician. Seek immediate medical care for emergencies. Eugene Baek, L.Ac. · New Jersey License 25MZ00080600