| | Why Your Trunk Can NEVER Be Stable

Author / Matthew Zanis

5 - 7 minute read

Core stabilization is a marketing fad aimed at profiting off the 90 billion dollar a year low back pain problem. We have seen it all from core-boards, to weightlifting belts and braces, to bulletproof your low back programs all targeting a solution to a problem that is, quite frankly, off the mark.  What is their intention? They purport that core stabilization is the only way to the spine and your back safe from pain or injury. I call bullshit.

Let’s start out by clearing the air and defining what the “core” really represents.

The core of the human body is much more than just the 6-pack guaranteed by every Instagram influencer out there on social media. Now that that’s out of the way, your core is everything below your neck down to your pelvic bowl, and everything within that defined space from front to back. This includes your lungs, diaphragm, shoulder blades, abdominals, and those two big loaves of french bread on your back called your spinal erectors.

Along the same lines, I propose a different term for your “core” that you will see utilized throughout the rest of this article. I propose that all of the above structures be included in the collective term – Trunk. Power Athlete CEO, John Welbourn, described it best: “Apples have cores. They rot and waste away. Trees, on the other hand, have trunks – strong, durable, and capable of withstanding the strongest winds.” I agree. I don’t want to think of you, the reader, as a fruit. You are a tree. You have a trunk. End of discussion.

How the Trunk Works

Trunk stabilization is exactly the opposite of how the human body actually operates in normal and healthy movement. Yes, from a performance perspective, if you are squatting 500 pounds or deadlifting a house, you would benefit from a stable core in this static environment. And, there is plenty of literature in the rehabilitation space to show that “trunk stability exercises” do have some carry over benefit to those with low back pain. Although, even more research shows that this specific form of exercise is really no better than general exercise or movement for decreasing back pain.

If trunk stability is truly a pipe dream, then what is the alternative? Let’s play a game. I want you to get up from your chair (if you aren’t already standing like you should be) and stand as still as possible. I mean it. DON’T MOVE A MUSCLE. What do you notice? Close your eyes and attempt this feat again. What you will find is that the human body can never be totally still. It is constantly in motion, gently swaying in the wind, adapting to the external stimulation of the environment around you. You will also notice that trying to limit movement of your body is actually more effort, as your brain and nervous system upregulate in an attempt to limit motion around joints.

I want you to shift your perspective. I want you to view movement as a way of improving stability, instead of isolation and limitation. In the case of pulling 800 pounds off the floor, you really wouldn’t want to have too much mobility, and totally rounding over you back, looking like a dog shitting razor blades. However, I can also make an argument for strengthening these less than optimal positions as a way of safeguarding you from injury and pain – cue the Jefferson Curl. My point is that having a “stable trunk” is only as good as your ability to move in and out of that strong set point. You need to develop awareness of mobility at the end ranges of spinal flexion and extension away from that “neutral” zone for lifting heavy load. If we neglect this aspect of training, we increase our risk for pain and injury later in life when our environment isn’t perfect, like twisting and picking up our kid’s crayon off the ground.

Compensations Don’t Cause Pain

We are also very much human and develop compensation patterns throughout our life. These compensation patterns lead to accelerated stress to specific tissues and could potentially lead to pain experience over time. Attempting to add stability to compensation patterns is counterintuitive, especially since we as coaches and rehabilitation professionals should be using movement exploration as a way to reduce pain and dysfunction! That being said, compensations and imbalances are not the sole cause of injury and pain. There are many other movement, psychosocial, and biological components that need to be considered. Follow the links below to my other articles on pain and stress to learn more.

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So, how do we enhance human movement and performance? We encourage both mobility and stability at each joint, giving our body and brain more movement bandwidth and durability by having more options to play with in our environment. We accomplish this by exploring the limits of our stability and shining light into the dark zones of our movement literacy.

Standing with your feet under your hips establishes your base of support, which is represented by the area around and between your feet. This is your “neutral” position, your brain’s perception of normal, it’s sense of safety. This is the position where your center of mass (the aggregate of all your muscle, fat, bone, and other body tissue), which is found about an inch below your belly button at your L4-L5 vertebrae, is located smack dab in the middle of your base of support. Ironically enough, this level of vertebrae at your spine is also the most mobile and most common are where people experience low back pain. This is why having a beer belly, or pregnant women, have a higher likelihood of experiencing back pain. All of that extra weight in front keeps shifting your center of mass forward.

As you move throughout life, walking, training, exercising, you are constantly adjusting as your center of mass leaves your base of support. If you didn’t adjust and adapt you would fall over, which is why older people typically develop balance problems. They move less, narrowing their base of support (think of that shuffling gait pattern), make their spine more rigid, and reduce mobility.

What About Isometrics? I Thought They Were Good For Me?

The short answer is YES. They are great for you, but we as coaches and providers tend to miss apply them in our training. When we move, the human body experiences all 3 types of muscular contractions: eccentric, isometric, and concentric…in that order. The key point here is that the isometric falls at the transition between the eccentric and the concentric contraction. To use our example above, the isometric falls at the edges of our movement capability where we reach limits of stability. This is why performing something like a see saw walk or single leg RDL is so difficult for many people.

One leg narrows our base of support and exposes us to the limits of our comfort zone. We hit that and range and tend to fall over or take a step to regain a large base of support. This exposure, where we hit an isometric at the end range of motion, actually enhances our stability by teaching our brain how to handle larger shifts in our center of mass.

ABMAT WOD Cash-Outs Don’t Get You Abs

Yet, think back to where many in our industry apply isometrics – in a “neutral” position! This is every static plank you ever held. Applying isometrics in this way establishes that we are trying to solidify a position that, in reality, we never truly find in movement or sport. And, if we do, it lasts for a split second. Even when under the load of a heavy back squat, the lumbar spine has been shown to flex up to 30 degrees! (Arjmand, et al. 2005). This line of thinking may make you or your clients feel strong or tight like your abs have just been pulled tight in a corset from the “burn,” but it limits performance potential by decreasing movement exploration and capacity. In order to have a stronger trunk, or “center/neutral position,” we need to understand where our boundaries lie and seek to expand them through movement. This means you must fail, providing your brain with awareness of these limits, and information to learn from in order to grow past these limits, improving your mobility.

In order to do this, the spine CANNOT remain neutral. Every muscle surrounding and attached to the spine must learn these same eccentric, isometric, and concentric waves of muscle action. They must learn to decelerate movement away from the spine, hit an isometric end range, and learn to concentrically pull back to center. I must make a very important point here: this center or “neutral” position is NOT a static point. It is a mere moment in time that our body transitions through. Think of a standing teapot with a dumbbell. You start at center, laterally flex away, finding your end range (usually defined by pulling or tightness limiting your motion), and  pull back through center to the opposite side, and back to center again. The same concept holds true for the complicated movement of sprinting. Instead of moving in one plane, the spine is a decelerating and producing force through all 3 planes of movement as the foot hits the ground and sends energy up through the pelvis.

Master Your Movement Daily

At the end of the day, your ability to “stabilize your spine” comes down to how well you move your m(ass). There is no secret squirrel program to a strong trunk. There is no quick fix trunk routine to eliminate back pain. The solution is simple, but that doesn’t mean it’s easy. Are you ready for it? Do  you think you can handle it? Here it comes…

Lift heavy shit, sprint fast, and explore new movement daily. Do weird stuff you don’t normally do. Learn new ways to manage your mass over your base of support. Challenge your perception of optimal. Get outside your comfort zone. Move like a dancer. Lift weights like Arnold. Explore the power of movement. The key to a strong healthy trunk is rooted in the process of movement discovery.

If you’re in need of movement direction, check out our Iron Flex accessory program. A daily dose of 10-15 minute movement therapy for all skill levels. Many use this as preparation and warm up for daily training, active recovery sessions, or mid-day movement to get up out of their office chairs. Check out a free 7 day trial of IronFlex linked below.

Related Content

EDU: ACL Injury Prevention – Power Athlete Academy
PODCAST: PA RADIO – EP 362: Injury Prevention w/ Dr. Adam Anz
BLOG: How The “Knees Out” Cue Caused Your Knee Pain by Dr. Matt Zanis
BLOG: Training Foot Health by Dr. Matt Zanis
BLOG: Now Your Daughter Doesn’t Have to Fear ACL Tear by Tex McQuilkin

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Matthew Zanis

PT, DPT, FAAOMPT, OCS, ATC, CSCS Former baseball catcher and an avid outdoorsman. Worked with Division 1 basketball, football, and track and field at the University of Pittsburgh, along with the Pittsburgh Pirates and Arizona Cardinals organizations. Received a Bachelors in Athletic Training from the University of Pittsburgh in 2011 and a Doctorate in Physical Therapy from Duke University in 2014. Is board certified in Orthopedics and a Fellow through the American Academy of Orthopedic Manual Physical Therapists. Is a PT with the United States Olympic Committee and USA Shooting. Currently operates his performance therapy practice in Scottsdale, AZ with Dr. Tom Incledon of Causenta Wellness, and became a Power Athlete Block One Coach in September of 2017.

Dr. Zanis utilizes the Power Athlete Methodology to optimize performance, reduce injury risk, and rehab his clients and athletes through movement assessment, coaching, and individualized program design.



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