Where the Muscle Is Located
The quadratus lumborum (QL) is a deep muscle in the posterior abdominal wall. It originates from the iliac crest and inserts onto the 12th rib and the transverse processes of the lumbar vertebrae. The QL plays a key role in lateral flexion of the spine, pelvic stabilization, and assisting with spinal extension.

Different Ways to Engage

1. Side Bend Isometric Hold: Stand upright and slowly bend sideways toward one hip, then hold the contraction at the end range.
2. Suitcase Carry (Unilateral Farmer’s Carry): Hold a weight in one hand and walk slowly while maintaining an upright posture, resisting lateral tilt.
3. Side Plank with Hip Drop: Perform a side plank and slowly lower and lift the hips using the QL for control.
4. Seated Side Lean Hold: While sitting tall, lean sideways and hold the position without rounding the back, engaging the QL unilaterally.
5. Standing Band Side Pull: Anchor a band and pull it laterally against resistance, using only the side body to initiate the movement.

How Long to Hold Flex for Muscle Growth

• Beginner: 5–8 seconds per side, 2–3 sets
• Intermediate: 10–15 seconds per side, 3–4 sets
• Advanced: 20–30 seconds under load or in extended positions, 4–5 sets

This muscle benefits from a mix of dynamic and isometric training, ideally 2–4 times per week.

Different Levels of Skill

• Beginner: Focus on bodyweight or gentle leaning exercises to build awareness and activation.
• Intermediate: Add light resistance or begin incorporating single-sided weight-bearing drills.
• Advanced: Include loaded carries, resisted side bends, and instability drills like uneven side planks.

How It Supports Other Muscles

• Obliques (Internal and External): Works alongside these abdominal muscles to perform and stabilize during lateral flexion.
• Erector Spinae: Collaborates during spinal extension and contributes to postural support.
• Gluteus Medius and Minimus: Coordinates during single-leg stance and helps stabilize the pelvis.
• Transversus Abdominis: Engages with the QL to maintain intra-abdominal pressure and spinal integrity during movement.

The quadratus lumborum is crucial for spinal support, core strength, and balance between the pelvis and ribcage. It’s especially important in preventing lower back pain and improving strength in functional and athletic movements involving twisting, bending, or carrying.