The quadratus lumborum (QL) is a deep muscle that runs from your last rib and lumbar vertebrae down to the top of your pelvis. It stabilizes the low back, side-bends the trunk, and hikes the hip. When it becomes overactive or develops trigger points, it can generate significant unilateral low back pain that mimics SI joint dysfunction or disc problems.
Typical presentation
- Deep, achy pain in one side of the low back, often at the base near the pelvis
- Worse with prolonged sitting, standing on one leg, or sneezing/coughing
- Pain with side-bending toward the opposite side
- Referred pain into the hip, SI joint region, or lower buttock
- Feeling of being "off" or shifted when standing
What overloads the QL
- Prolonged asymmetric sitting (crossing legs, sitting with wallet in one pocket)
- Leg-length discrepancy or a hemi-pelvis anatomical asymmetry
- Repetitive one-sided lifting or reaching
- Weak glute medius on the same side (QL substitutes for weak hip stabilizers)
- Post-injury guarding
How to test
Palpation reveals a very tender, ropy band deep in the low back, and reproducing the patient's pain with pressure often confirms it. Side-bending and hip hiking tests can be revealing.
Treatment
Soft tissue therapy — deep manual work and Graston/ART on the QL and thoracolumbar fascia.
Dry needling — often the fastest intervention for stubborn QL trigger points.
Joint mobilization for the lumbar spine and pelvis.
Glute medius strengthening — the primary fix for chronic QL overload. If the hip stabilizer works, the QL doesn't have to.
Postural correction — sit symmetrically, avoid wallet-in-pocket, address leg length if significant.
Home protocol
- Side-lying QL stretch — 30 seconds, 3x each side, daily
- Side plank progression — clam shells, then side plank on knees, then full
- Glute medius activation with a band around the knees
QL pain often responds fast to targeted care. If you've been treated for "low back pain" without lasting relief, the QL may be the missed piece.