How to Do the Williams Low Back Flexion Exercises

If you’ve ever experienced lower back pain, you know how much it can interfere with daily life. One exercise commonly recommended by physical therapists is the Williams low back flexion exercise, a simple movement designed to gently stretch and mobilize the lumbar spine. Done correctly, it can help relieve discomfort and support spinal health especially for certain back conditions.

Here’s what you need to know before adding it to your routine.

What Is the Williams Low Back Flexion Exercise?

Also known as lumbar flexion or low back flexion, this exercise involves rounding the lower back while lying on your back. It’s often used in physical therapy settings to improve mobility, ease stiffness, and reduce pressure in the lumbar spine. It’s especially helpful for people with:

• Spinal stenosis

• Spondylolisthesis

• Facet joint pain

• Certain types of sciatica or post-disk herniation recovery (with caution)

Unlike more aggressive back movements, this flexion-based exercise places minimal strain on the spine, making it a safe starting point for many experiencing chronic or mild lower back pain.

When (and When Not) to Do It

Best for:

• Mild to moderate chronic low back pain

• Post-acute recovery from disc bulges (with professional guidance)

• Older adults with age-related spinal compression or stiffness

Avoid if:

• You’re in the acute phase of a herniated disc

• You experience worsening leg, buttock, or thigh pain while performing it

• Your symptoms intensify instead of centralizing

If you’re unsure, always consult with a physical therapist or healthcare provider. Pain that radiates further down the leg during the exercise is a sign to stop.

How to Perform the Basic Supine Low Back Flexion Exercise

You don’t need a gym or equipment just a soft, supportive surface.

Instructions:

1. Lie on your back on a firm but padded surface (avoid soft beds).

2. Bend your knees and keep your feet flat on the floor.

3. Slowly bring both knees up toward your chest.

4. Use your hands to gently pull your knees in. (Hold the thighs instead of the knees if you have knee pain.)

5. Hold for 3 seconds.

6. Slowly lower your feet back to the floor.

Reps: Perform 10 repetitions, monitoring how your body feels.
If pain improves or centralizes, you can continue. If symptoms worsen, stop and seek guidance.

Pro tip: This movement can be repeated several times a day during flare-ups. As pain subsides, reduce frequency to once daily for maintenance.

Progressing the Exercise Safely

As you become more comfortable, your physical therapist may suggest progressing the movement. Two common next steps include:

• Seated Flexion: Sit on a chair, feet flat. Lean forward, reaching hands toward the floor between your knees. Hold for 2–3 seconds, then return to sitting upright.

• Standing Flexion: Stand with feet hip-width apart. Slowly bend forward, reaching toward your toes. Hold for 2–3 seconds, then return to standing.

If you feel any pain during these more advanced versions, scale back to the previous level and check in with your PT.

Balance It With Extension

Flexion exercises can place forward pressure on the spine. To counterbalance, consider following them with a gentle lumbar extension, like:

• Prone press-up: Lie on your stomach and push your upper body up using your hands, like a cobra stretch.

• Standing backbend: Place hands on your hips and lean back slightly.

Just 1–2 reps are enough. These help neutralize the spine and maintain balance between flexion and extension.

Final Thoughts

The Williams low back flexion exercise is a low-impact, effective way to improve lumbar flexibility and reduce discomfort especially when you're managing age-related changes or certain back conditions. But it’s not a one-size-fits-all fix. Listening to your body and getting professional advice are key.

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