Quadratus Lumborum Strain

The quadratus lumborum is a deep muscle in the lower back that plays critical roles in lateral flexion stabilization and respiration. Strain refers to overstretching or tearing of muscle fibers leading to localized pain. QL strain is a common cause of mechanical low back pain often misattributed to other lumbar pathology.

Mechanism of injury includes lifting heavy objects with poor technique sudden side bending or twisting prolonged sitting with leg length discrepancy and overuse during sports involving rotational movements. Pain is typically unilateral deep aching and located lateral to the spine. It worsens with standing walking and bending and may radiate to the hip or groin.

Diagnosis is clinical based on tenderness over the QL muscle pain reproduction with side bending and exclusion of disc herniation or facet pathology. Imaging is rarely needed unless red flags are present. Treatment includes activity modification stretching strengthening of core stabilizers manual therapy heat application and nonsteroidal anti inflammatory drugs. Trigger point injections may help refractory cases. Recovery is typically four to six weeks with appropriate rehabilitation.