Beyond the “Core”: Mastering True Trunk Stability | EP1

In this episode, we dive into what true trunk stability really means — and why it’s so much more than just training your “core” or chasing six-pack abs. We unpack the deeper system of muscles and fascia that support your body, protect your spine, and help you move efficiently in everything from sports to daily life.

You’ll learn the importance of internal pressurization, the role of key stabilizing muscles, and how to build resilience and longevity through practical movement strategies. Plus, I share my favorite foundational positions and drills to help you start improving your trunk stability right away.

Whether you’re an athlete, a practitioner, or just want to move better and feel better, this episode will give you tools and insights you can apply immediately.

👉 If you enjoyed this episode, please subscribe, leave a review, and join my community on Skool at school.com/movementbasetherapy. 

Transcript

Hey, and welcome back to the MBT podcast. Thank you for joining me on this episode three, where we will be talking about unlocking true — I want to say — trunk stability. I don't really want to call it core, but we'll get there here in a bit.

The main focus here is talking about trunk stability, how to create rigidity, how to utilize the system in regards to the kinetic chain, and how it applies in everything you do in life — from sport to posture. But that's pretty much the summary of this episode here.

I want to introduce myself. My name's Sheldon. I've been in the sports medicine industry for a little over five years. I've been in the health, wellness, fitness industry for a little over two decades now. And I just want to utilize this platform to share my experience, my perspective, my outlook. We can tie into a little philosophy, but I want to try to keep it on track here with the whole idea of this being a sports medicine podcast.

Sports medicine podcasts — yes, there are many out there — but at the same time, this is one perspective of many. And the thing that gravitates community is the likeness, the ability to relate. I just hope to inspire the up-and-coming generation and share insights and experience. Maybe this is something that you connect with, whether you're a practitioner or if you're seeking to develop. This is just the place to be.

Thank you for joining me again. My name's Sheldon and I look forward to getting into this episode with you all.

We’re going to start off here with the first segment where we talk about: what is trunk stability? You might say, trunk? What do you mean by trunk? But if I say core stability, there is a little bit more of a societal acceptance to that word. And I get it, but I'm not here to appease the masses.

I'm here to follow what the science says, follow the theory, follow the concepts, the principles, understand and respect things like tissue healing phases, and be open-minded to progressive treatments and staying up to date when it comes to healthcare technology. It’s about the ability to live longer, build longevity and resiliency, and develop these characteristics not just in your career but in everyday life.

Life is movement. Movement doesn't just end when you're thinking about your posture — maybe you have to pay more attention to how you lift things because you're a manual labor type of person, or maybe you just use your body in general. It never turns off. It's not like you go home and turn into a sack of potatoes on the couch and zone out.

We're always thinking about it from a longevity standpoint. Whether it's how you recover, whether it's active recovery, days off — the things you do accumulate. They don't have to be a whole lot. It can be a little and it can be a slow burn where you just practice at it, chip away at it, continue to refine, hone, sharpen the sword to become better at it.

It's what gets you up in the morning. It's the reason that gives you purpose, fulfillment, and meaningfulness. We all need that in our own lives, in our own ways, shapes, and forms. That’s the personal journey, right?

But I digress. So, I want to stay on the topic of what is trunk stability here. We have to understand that it's beyond societal norms. What is aesthetically pleasing isn't necessarily what's going to be functional.

When we think about core, most people think about the rectus abdominis — the six pack. And sure, but that is one player in the big ocean of trunk and circumferential stability that we have to create.

When you think about six pack, it's the thing that brings everything together — like the suture to the wound. It holds it together, but it's not the end all be all. You have systems and components that are comprised of the bigger picture, which is the cylinder of our torso, from front all the way around to the back.

That is your internal and external obliques. Those are going to help with rotational forces and absorption. They connect into the fascial system and the whole kinetic chain. When you think about internal/external obliques, look a level up and you’re looking at your lat; look a level down and you’re looking into your adductor and then into your lower leg and plantar fascia.

This is the entire oblique sling. Internal and external obliques are key players when it comes to integrating the system together.

Then you have your transverse abdominis. If it wasn't for anything, it would be the transverse abdominis as the cornerstone, because it’s that circumferential stabilizer that helps us expand and load against compressive and rotational forces. It is the sling that connects the trunk as a system.

Without the transverse abdominis, we would not be able to absorb compressive forces as efficiently because it holds everything together. Think of it like wearing a corset — it wraps everything together, integrating the rectus abdominis to your paraspinals and your thoracolumbar fascia.

This is one entire stretch of tissue that connects and binds. The key here is rotation and absorption of compressive forces. Engineers out there: this is essentially what shearing is — rotational and compressive forces creating shearing forces on the trunk system.

Whether you think about a muscular strain, we have rotational shearing type forces that can induce a tearing or rupturing effect depending on severity. But that’s for another episode.

Transverse abdominis is the big key player that keeps everything together. Then we have our paraspinals.

A good acronym for you studying folk: "I Love Spaghetti" — iliocostalis, longissimus, and semispinalis. Those are your three spinal erectors or paraspinal muscles. Those big slabs along the side of your spine — you have one on each side. They’re key players as well.

We also have deep internal muscles that can segmentally flex and extend our spine. It’s not just the paraspinals holding us up. We have muscles like the multifidi that can create segmental motion on the spine itself.

We must understand the vital importance that it’s not just rectus abdominis when it comes to core. There's so much more to it. We have a deep stabilizing system — your diaphragm, pelvic floor, and multifidi.

Without these three, we wouldn't be able to create internal pressurization against our external wall, which is our trunk. This internal pressure pushing out against the external wall dictates injury prevention and reduction.

If we think about resiliency and what a herniation is (like an umbilical hernia), it’s your intestines pushing through your abdominal wall. Even elite athletes can have sports hernias because they create so much internal pressure that they need a strong external wall to absorb it.

Even for sedentary individuals, this is a risk because gravity is a constant. We are always absorbing compressive forces — whether supine, prone, or upright. We have to build resiliency daily to withstand the "weight of the world" as we move through it.

When we talk about posture, it’s essentially optimized movement. Whether it’s sports performance, ergonomics, moving objects, doing job tasks — even parenting has a posture component.

Your body compensates when standing offset, leading to more compressive force on the joints: ankle, knee, hips, spine.

If you’re supine, there’s still gravity, but less risk than upright. You can’t live supine forever. Sedentarism is a symptom (or attribute) of poor physical activity.

Now that we’ve talked about posture, let’s understand common misconceptions when training your trunk. It’s more than just sagittal range of motion. Most people love crunches and six-pack workouts. Yes, that’s one component — good for resiliency — but not the whole story.

When we talk exercises or rehab, intra-abdominal pressure is foundational — utilizing the diaphragm against the external abdominal wall.

Yes, you can do crunches or leg raises. But I don’t recommend scissors kicks in supine without adequate stabilization. Many end up with flared ribcages and anterior pelvic tilt, creating unfavorable pressures and excessive spinal compression.

Your spine is like a jelly donut: the center (nucleus pulposus) is jelly-like and hydrated, surrounded by annular fibrosis — strong cartilaginous fibers. As we age, hydration declines, affecting resilience.

You can find many trunk exercises online: anti-rotation press-outs, intra-abdominal pressurization (Valsalva, for example). But it’s not just “hunker down, yep, you’re doing it.” You must respect the concepts and ensure proper activation and cueing.

Training is about exposure and dosage — modulating volume, intensity, ensuring rest and recovery, and integrating it as a lifestyle rather than just ticking a box.

When it comes to nutrition, the same mindset applies. Many think in terms of goals: “I’m on keto to lose 10 pounds.” But what happens after?

Why not think long-term, finding what you enjoy in moderation and building it into your life? Moderation and awareness are key — knowing what’s too much or not enough.

Whether you’re an athlete, laborer, or just someone moving through daily life, it’s about resiliency and recoverability. Movement is foundational.

Without sufficient trunk stability and pressurization, we can develop issues: low back pain, poor force transmission, poor coordination, increased injury risk.

To maintain readiness, we need cardiovascular fitness, resistance training, efficient movement patterns. Inefficiencies cause uneven wear and tear and increase neural load.

A study on soccer athletes (ACL reconstruction vs. non-injured) showed more brain activity in the reconstructed athlete during movement — not ideal. It means less efficiency, more neural demand.

We rebuild these patterns step by step. Starting with intra-abdominal pressurization and diaphragmatic breathing — progressing from supine supported “three-month” position, to six-month, to unsupported, to verticalization, and beyond.

The less support, the more challenge. For example: standing on one leg is more challenging than lying on the ground.

In supine “three-month,” focus on rib position, lumbar support, cervical lengthening, broad chest, belly breathing, and relaxed lower extremities.

These foundational cues build the framework for higher-level movement. From there: side-lying positions for upper/lower differentiation and scapular stability.

From side-lying, go to prone. Focus on pelvic alignment (posterior tilt), stacked pelvis and diaphragm, rib cage down, elongation, active hand contact, neck lengthening.

Then progress to half kneeling, verticalization, or sport-specific positions.

For surfers, you need rotational ability, trunk stability, scapular stability, and lower/upper body dissociation. The fascia system is your force transmitter — the more efficient, the more effective.

Other favorite exercises: 90-90 hip openers, side support for breathing and lengthening, crawling patterns for anti-rotation and oblique sling activation.

Recap: We covered trunk stability as a system, misconceptions, importance of posture and stabilization, dysfunctions from poor sequencing, and practical strategies you can use today.

Thank you for listening! This has been 15 years of “I’ll do it tomorrow,” finally happening.

If this was helpful or interesting, please leave a review, subscribe, and follow @sheldon.mbt. Join the Skool community at school.com/movementbasetherapy.

Thanks again for listening — and I’ll catch you in the next one.