The Hidden Muscle Behind One-Sided Back Pain

Date: November 29, 2025

What Is the Quadratus Lumborum?

The Quadratus Lumborum (QL) is a deep core muscle located on both sides of your lower back. It connects your pelvis to your spine and ribs, helping your body:

Bend sideways and rotating your trunk
Stabilize your spine and pelvis
Transfer power between upper & lower body

It’s a key stabilizer for athletes and active individuals — especially those who twist, rotate, or throw during sport.

Why One Side Gets Overused

Many sports and daily activities naturally favour one side of the body.

If you play golf, tennis, baseball, ice hockey, or pickleball — or even habitually carry a child or bag on one side — your body begins to move unevenly.

Over time, this leads to:

One QL working harder than the other
Tightness and muscle imbalance
Compensation through the hips and spine

The result? Persistent low back tightness or pain that doesn’t fully resolve — even with stretching.

The “Pitcher’s QL Problem”

Take a right-handed baseball pitcher as an example. Each throw requires powerful rotation to the left, forcing the left QL to stabilize and decelerate the trunk.

Over time, that left QL becomes tight, overworked, and sore.
This same imbalance shows up in tennis servers, golfers, and hockey players who repeatedly rotate one way.

If not corrected early, it can develop into chronic pain or reduced performance.

The “Pitcher’s Ql Problem” — *The “Pitcher’s QL Problem”*

How QL Overuse Feels

You may notice:

A deep ache on one side of your low back
Pain that worsens after twisting or standing
Tightness that doesn’t ease with stretching
Difficulty sitting upright for long periods

It often feels like “core weakness” or “hip stiffness,” but the true problem lies deeper — in your QL and the surrounding stabilizers.

Real Client Example

At Pain Free Health, we treated a client who developed a left-sided QL strain after years of one-sided sport mechanics.

Their right-handed sport led to over-rotation in one direction, forcing the left QL to overwork. The imbalance built gradually until the muscle finally gave out under stress.

Key lesson: these imbalances don’t appear overnight — they accumulate over time.

Long-Term Complications if Ignored

When QL imbalance isn’t addressed, it can contribute to:

Chronic low back pain
Hip or sacroiliac (SI) joint dysfunction
Rib or breathing restrictions
Disc irritation or nerve pain
Reduced power and performance in sport

How to Prevent QL Overuse

Balance is the solution.
Focus on these strategies to protect and retrain your core:

Strengthen both sides of your core evenly
Train anti-rotation and rotational control
Improve hip mobility (especially the opposite hip)
Maintain good posture and movement variety
Include stretching and recovery work in your routine

Two Simple QL Exercises You Can Try at Home

1. Side-Lying QL Stretch

Lie on your right side with your legs straight.
Reach your left arm overhead and gently lean your upper body to the right, creating a stretch along your left lower back and side.
Hold for 30–45 seconds, then switch sides.

Tip: Keep breathing deeply to help release tension.

2. Suitcase Carry (Anti-Lateral Flexion Exercise)

Hold a moderate dumbbell or kettlebell in one hand only.
Stand tall, brace your core, and walk 10–20 steps without leaning toward the weighted side.
Switch hands and repeat 2–3 sets per side.

Why it works: strengthens both QL muscles evenly and improves trunk stability.

How Pain Free Health Can Help

At Pain Free Health Clinic, our physiotherapists specialize in identifying and correcting muscle imbalances like QL dysfunction.

We use a combination of:

Shockwave Therapy to reduce muscle tension
IMS/Dry Needling to release deep trigger points
Targeted exercise programs to restore balance and stability

Whether you’re an athlete or someone experiencing chronic back pain from daily habits, our team can help you move better, feel stronger, and stay pain free.