How to Fix Butt Wink in Squats: What Causes It and What You Can Do

By Alexander Morrow – Fitness First Academy

If you’ve ever recorded your squat and noticed your lower back tucking under at the bottom—almost like your tailbone is curling forward—you’ve experienced what’s known as a butt wink.

While it might sound harmless, repeated butt wink under heavy loads can increase stress on the lumbar spine and put you at risk of injury over time. As a personal trainer and strength coach, I see this issue pop up often, especially with beginners or lifters chasing depth without proper mobility.

Let’s break it down:

What Is Butt Wink?

Butt wink is the posterior tilt of the pelvis that happens at the bottom of a squat, usually just before or as you hit parallel or go below. Instead of maintaining a neutral spine, your pelvis tucks under, and your lower back rounds.

This is especially common in barbell back squats, where load and depth can expose mobility limitations.

What Causes Butt Wink?

There isn’t one singular cause—it’s usually a combination of factors:

1. Limited Ankle Mobility

If your ankles can’t dorsiflex (bend forward) enough, your hips compensate to allow more depth. This often results in your pelvis tilting under at the bottom.

2. Tight Hamstrings

Tight or overactive hamstrings can limit hip flexion, pulling on the pelvis and causing it to rotate posteriorly as you descend.

3. Poor Hip Mobility

Restricted internal rotation or flexion at the hip joint can prevent a deep squat without compensation.

4. Structural Anatomy

Some people have longer femurs or shallower hip sockets. This means their squat mechanics will look different, and some pelvic tilt may naturally occur at the bottom.

5. Overemphasis on Depth

Chasing “ass to grass” depth without the mobility to support it is a recipe for butt wink.

Why It Matters

A slight butt wink with bodyweight may not be a big deal. But under a heavy barbell, lumbar rounding puts your spine in a compromised position—especially if repeated over time. It shifts the stress from your hips and glutes (where you want it) to your lower back.

How to Fix or Minimize Butt Wink

1. Improve Ankle Mobility

• Try wall ankle mobilizations or weighted dorsiflexion drills.

• Spend time in deep squat holds to open up the ankles and hips.

2. Strengthen Core and Glutes

• Focus on bracing with RKC planks, dead bugs, and bird dogs.

• Activate glutes before squatting with bridges or banded abductions.

3. Stretch and Mobilize Hamstrings (Smartly)

• Use dynamic hamstring mobility, not just static stretching.

• Foam roll the posterior chain to reduce tension before squatting.

4. Adjust Squat Depth

• There’s no rule saying you have to go rock bottom. Squat to the depth that allows you to maintain a neutral spine.

• Box squats or tempo squats with a controlled range can help re-train depth awareness.

5. Experiment with Foot Position

• A slightly wider stance and a small toe flare can open up the hips and reduce stress on the pelvis.

6. Use Heel Elevation (Sparingly)

• Lifting shoes or small plates under the heels can temporarily improve squat mechanics by compensating for poor ankle mobility.

• Long term though, address the root cause.

Final Thoughts

Correcting butt wink is less about being “perfect” and more about building awareness, improving mobility, and squatting in a way that works with your body—not against it.

At Fitness First Academy, I coach clients to move better, not just lift heavier. If you’re unsure if you’re dealing with butt wink or want a full movement assessment, shoot me a message. I’ll help you break it down and build a stronger, safer squat from the ground up.

About the Author

Alexander Morrow is a NASM Certified Personal Trainer, ACE Certified Personal Trainer, ACE Certified Group Fitness Instructor, NCSF Certified Strength & Conditioning Coach & ACE Fitness Nutrition Specialist with a passion for helping people reach their fitness goals. With a focus on strength training and functional movement, he believe in building a strong, capable body from the inside out. Connect with @FitnessFirstAcademyF1A on Instagram or visit www.FitnessFirstAcademy.com/blog for more training tips and inspiration.

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