It’s time to debunk myths and set the record straight about the tuck. I’m talking about the pelvic tuck, also known as the pelvic tilt. For a while now, the tuck has become far too popular in fitness vocabulary. The word “tuck” has been used by weightlifters and CrossFit coaches to teach athletes to how to engage their glutes and open their hips; think at the top of a squat or a box jump. Yoga teachers have also taken to using the term to cue a flattening of the spine to prevent low back crunching. The tuck originated as a well-intentioned correctional cue. However, the tuck has taken on a life of it’s own. From a biomechanics perspective, the tuck is causing more harm than it is good as people are misunderstanding it’s proper use and purpose.

To illustrate this, I am going to introduce a new concept called Nutation. Nutation is a term that refers to a tilting angle of the sacrum in space. As a reminder, the sacrum is the large wedge shaped vertebra at the inferior end of the spine that intersects with the hip bones to form the pelvis. The sacrum is an incredibly strong bone that supports the weight of our entire upper body. By nutating or tilting the pelvis, we are creating a different distribution of weight onto the low back.

In the picture below, we are shown three different angles of nutation; posterior, neutral, and anterior. The first stick figure is effectively demonstrating the tuck. This posterior tuck is known in the biomechanics world as Counternutation. As you can see from this extremely basic depiction below, counternutating is when you curl  your sacrum, tailbone, and pelvis underneath your spine. Doing this removes any kind of lengthening arch on your low back, and actually shortens your low back, increasing pressure on certain spinal discs. While an exaggerated low back arch (also known as a lorodic curve) is problematic and leads to a swayback, a natural curve in the low back is a healthy arch and allows for optimal performance. When you have the correct arch you experience the most freedom and capability in movement. Somewhere along the way the natural low back arch has been sacrificed for a counternutated, tucked pelvis, and it’s a problem.


I’m seeing counternutation everywhere; when people walk, sit, stand, lunge, squat, deadlift, plank, pull, they are counternutating. In the short-term, excessive posterior tilt in the pelvis will shut off access to deeper glute muscles and throw off posture and natural distribution of weight onto the sacrum. It creates more of a flattened ‘packcake’ butt look, instead of a lifted “apple-bottom”. Sustained counternutation can cause people to lose the natural curvature of the spine and lose control of the ability to hip hinge. This is experienced as stiff, locked hip joints and an inflamed and irritated (angry) SI joinst.

One way to reverse the effects of a counternutated pelvis is to simply nutate or rotate in an anterior direction (see third stick figure above). When we nutate our pelvis we literally begin to create more connection between our hip pointers because it draws them towards each other. It also doesn’t stress out your pelvic floor muscles, which leads to greater neural communication between your hamstrings and glutes. Once that happens you get greater access to these powerful muscle groups and learn how to load the weight on them correctly. Tucking, or counternutating, will actually shorten this region and disrupt the neural pathway to these areas.  As an added bonus, nutation will also allow you to engage deeper core muscles that lie between the pubic bone and the bellybutton.


With a healthy anterior pelvic tilt, you will eventually develop stronger and more powerful hips and a better balanced body! If you’re somebody who suffers from stiffness or inflexibility, a lot of this could be stemming form your frozen sacrum/pelvis. If you are an athlete of any kind, the secret to success and progress lies in the hip flexors. Addressing this now will let you see gains for the long haul! A well proportioned low back arch with consistently working core muscles will help develop a better hip hinge and a more explosive hip extension. Over time your leg muscles will get stronger and your posture will become more upright. From an efficiency standpoint your body will start to be able to do more work for longer while exerting less effort to do it.

Remember, extremes are never the answer and an exaggerated anterior tilt without the consciousness of core activation will put you at risk for low back irritation. Your core and low back must work in tandem to produce a combination of engaged core and lengthened spine.  Your goal as a mover, an athlete, a human in this world, is to find a balanced pelvis with full accessibility to your glutes, posterior chain, and deep core muscles.

Is there a time and a place for the tuck? Sure!  If you’re testing a max squat or a deadlift and need to keep the glutes locked in place to form a secure base then sure, tuck away! However, in day to day motion and general training the tuck is not a place to hang out.


This week’s video and offered exercise can help you bring awareness to your sacrum and pelvic tilt. Using three informative exercises, I want you to implement these into your life to improve your posture, functioning, and performance in the world. The first exercise is the wall deadlift. You can do this with or without weight. Be sure to focus on keeping the chin to the chest, butt on the wall, and belly muscles working. Do 2-4 sets of 8-12 reps. The second exercise is the goblet squat. This is used to “unlearn” the tuck. Take your time with it, and do 3-5 sets of 5 reps. Make your legs burn and stay upright! Same goes for the chin, do not let your head crank back and up ( I call this “pez-head). Lastly, sit on the floor in an L shape and see if you can sit upright, creating a natural low back arch. If this is hard for you, chances are you might be overly reliant on the pelvic tuck and your low back and hip joints are too tight.

Call me over when you give this a try and I can help you diagnosis and remedy the situation. With enough practice you’ll start to create more supple glute muscles that are stronger and better functioning. Once you start correcting your pattern I promise you’ll see an improvement in your low back, hip mobility, and how you perform in the world. That’s all for now, folks. And remember… when asked how many tucks you give, the answer is ZERO. ZERO tucks given.

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