Butt Wink During Squats: Why it Happens

published by: Debbie Luna
Last Updated:
June 22, 2022

Despite its playful name, the term butt wink actually refers to an error made in the performance of the squat wherein the exerciser rounds their back at the end of the eccentric portion of a repetition, increasing their risk of injury and reducing muscle fiber recruitment.

Fortunately, the butt wink may be remedied quite easily once the culprit cause behind it has been found - which is usually the main issue, as the butt wink can be due to quite a few different reasons relating to the squat or the exerciser’s usage of preparatory work.

Regardless of the particular cause behind the butt wink, exercisers must remedy this particular issue as soon as possible if they wish to continue performing the squat exercise, as the butt wink can eventually lead to painful lower back and spine injuries.

What Does the Term Butt Wink Refer to?

In more specific terms, the butt wink is a deviation away from correct spinal and pelvic neutral curvature at the bottom of the squat movement pattern, resulting in flexion of the lumbar spine during a point of increased stress.

From an external point of view, this appears to be the exerciser’s tailbone and buttocks rounding forward, flattening the lower back instead of creating a pronounced curve that indicates a neutral spinal column angle (illustrated below).

Pictured Left is Butt Wink - Pictured Right is Correct Form

Not only does this itself present several disadvantages to the exerciser, but it will also greatly affect other form cues and mechanics throughout the performance of the squat, potentially altering the form of the entire repetition.

Is the Butt Wink Dangerous?

Though the butt wink may not be immediately dangerous, it is capable of inducing injuries throughout the pelvis, knees and back if not corrected quickly.

When allowed to occur over multiple training sessions, the butt wink can eventually lead to sprains of the hips and tailbone, compressed, slipped or otherwise damaged lumbar spinal column discs and even instances of pinched nerves that may become medically serious if left untreated.

Exercisers currently suffering from butt wink while squatting need not worry, however, as this particular error in squat mechanics is rather easy to remedy once the exerciser realizes they are doing it.

Why is the Butt Wink Dangerous?

Primarily, the butt wink is dangerous as it bends the pelvis and spinal column in an inopportune moment wherein the tissues are under an additional amount of stress due to the squat exercise, providing the perfect environment for sustaining an injury.

However, several other risks also directly stem from the butt wink, such as increased pressure being placed on the knee joint and all the associated dangers of failing a repetition as the butt wink reduces the exerciser’s force output capacity at the most crucial point of the repetition.

Does the Butt Wink Mean Squatting Should be Stopped?

Experiencing butt wink during one’s performance of the squat does not mean that they should necessarily stop squatting, as it is further (and corrected) performance of the squat that can best remedy the issue, aside from the usage of proper mobility routines.

That being said, unless the exerciser has managed to pin down the culprit behind their butt wink issue, it is best for them to either reduce the intensity of their squat exercises or stop entirely until they are sure that they are capable of remedying the problem.

When in doubt, the exerciser may seek the advice of a certified athletic coach so as to ascertain whether their form is correct or if any other deficits are contributing to their butt wink.

The Main Reason the Butt Wink Occurs

By far the most common reason the butt wink occurs is due to a lack of sufficient mobility in the hips and any tissues connecting therein, such as the hamstrings and hip adductor muscle groups or the ligaments that attach them to the skeleton.

This is most noticeable in particularly low squat depths, wherein the butt wink becomes more pronounced as the pelvis is forced to tilt forward from a reduced range of motion surrounding the hip joint.

Moreover, this lack of mobility concerns practically every kinetic function of the hip joint, including hip flexion and femur-hip rotation in both axes - and as such requires a comprehensive flexibility routine in order to fix the butt wink.

Other Factors Behind the Butt Wink

Though a lack of proper lower body mobility is the usual reason why the butt wink occurs, several other factors may contribute or otherwise be directly responsible for it.

Among these are a weakened or improperly braced core, synergist muscle imbalances in the hips and lower back as well as the barbell being placed too low along the back (if the exerciser is performing a barbell squat in the first place).

Each and every factor contributing to the risk of butt wink must be carefully studied by the exerciser and corrected appropriately prior to attempting the squats at full intensity once again - as each of these contributing factors require their own unique solution to fix.

This is done to ensure that, even with sufficient mobility and proper form adherence, the exerciser does not risk injury once again by still retaining the butt wink.

How to Remedy the Butt Wink

Different strategies correspond to the many different reasons behind the butt wink - most of which the exerciser should be doing in the first place, regardless of whether the butt wink is actually plaguing their squat form or not.

For issues concerning mobility and reduced range of motion, a proper stretching routine and warm-up prior to beginning the squats exercise itself should greatly aid in reducing the severity or occurrence of the butt wink.

In the case of muscular imbalances, weaknesses or the exerciser failing to brace the core appropriately, the performance of highly targeted isolation exercises should remedy these factors over time.

If the exerciser is experiencing pain, numbness or other signs of injury relating to the butt wink, they must first take an appropriate length of time to rest and recover, as well as seek the attention of a medical professional prior to attempting to correct the cause behind their butt wink.

References:

1. Myer GD, Kushner AM, Brent JL, Schoenfeld BJ, Hugentobler J, Lloyd RS, Vermeil A, Chu DA, Harbin J, McGill SM. The back squat: A proposed assessment of functional deficits and technical factors that limit performance. Strength Cond J. 2014 Dec 1;36(6):4-27. doi: 10.1519/SSC.0000000000000103. PMID: 25506270; PMCID: PMC4262933.

2. Endo Y, Miura M, Sakamoto M. The relationship between the deep squat movement and the hip, knee and ankle range of motion and muscle strength. J Phys Ther Sci. 2020 Jun;32(6):391-394. doi: 10.1589/jpts.32.391. Epub 2020 Jun 2. PMID: 32581431; PMCID: PMC7276781.

3. Mata AJ, Hayashi H, Moreno PA, Dudley RI, Sorenson EA. Hip Flexion Angles During Supine Range of Motion and Bodyweight Squats. Int J Exerc Sci. 2021 Aug 1;14(1):912-918. PMID: 34567352; PMCID: PMC8439674.

4. Bohannon RW, Gajdosik RL, LeVeau BF. Relationship of pelvic and thigh motions during unilateral and bilateral hip flexion. Phys Ther. 1985 Oct;65(10):1501-4. doi: 10.1093/ptj/65.10.1501. PMID: 4048287.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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