“Butt Wink” During Squats: Is It Hurting Your Back?

What Is a “Butt Wink”?

If you've ever recorded your squat or worked with a coach, you may have heard the term “butt wink.” This phrase refers to the moment when your pelvis tucks under at the bottom of a squat — essentially, your lower back rounds slightly as you reach your deepest point.

For some athletes, this is a minor form issue. For others, it can signal a mobility limitation or an increased risk of low back strain. So, is the butt wink a big deal? Let's break it down.

Why Does the Butt Wink Happen?

There are several reasons the pelvis may tuck under at the bottom of a squat. Some of the most common include:

1. Limited Ankle Dorsiflexion

Tight calves or restricted ankle mobility can prevent your knees from traveling forward over your toes, which pushes your hips backward and forces your lower back to compensate.

2. Tight Hamstrings or Posterior Chain

Limited flexibility in the hamstrings and glutes can pull the pelvis into a posterior tilt during deep squats, especially under load.

3. Poor Core Control

A weak or poorly timed core can lead to loss of spinal stability at the bottom of a squat, contributing to lumbar flexion.

4. Squat Depth and Technique

Everyone has a unique squat anatomy based on hip structure, limb length, and mobility. Pushing past your available range just to “go lower” can result in compensatory movement patterns, including the butt wink.

Is the Butt Wink Dangerous?

A small amount of posterior pelvic tilt at the bottom of a squat may be totally normal and pain-free for many people — especially when lifting bodyweight or light loads.

However, under heavy load, a butt wink can place excessive stress on the lumbar spine. Repetitive lumbar flexion under load can increase the risk of disc irritation or low back strain.

That’s why it's important to understand the root cause and make corrections where needed — especially for athletes who squat regularly.

What Can You Do About It?

Assess Ankle Mobility

Try a simple knee-to-wall test. If you can’t get your knee to touch the wall without lifting your heel (4–5 inches away), work on calf flexibility and ankle dorsiflexion.

Stretch and Mobilize the Hips and Hamstrings

Include dynamic warm-ups and targeted mobility work like hamstring stretches, deep squat holds, and 90/90 hip mobility drills.

Build Core Stability

Strengthen the core with exercises like dead bugs, planks, and anti-rotation presses. Focus on maintaining a neutral spine under load.

Adjust Your Squat Depth

It’s okay to limit squat depth if mobility isn’t there yet. Use a box squat or pause squat to control range and maintain form.

Try a Different Squat Variation

Front squats, goblet squats, or heel-elevated squats can reduce the demand on the hips and ankles and may help keep a more upright torso and neutral pelvis.

When to See a Sports PT

If you’ve tried mobility drills, adjusted your form, and still notice significant low back rounding — or worse, if you experience back pain when squatting — it’s time to consult a sports physical therapist.

At Infinite Athlete, we specialize in movement analysis and can help you identify the root cause of your squat limitations. Whether you’re a weekend warrior or a competitive athlete, optimizing your squat mechanics can reduce injury risk and boost performance.

Final Thoughts

Not all butt winks are created equal. Understanding what’s happening in your body during a squat — and why — is key to safe and effective lifting. Train smart, stay mobile, and don’t hesitate to seek professional help if something feels off.

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