From back pain to better posture: how your inner core supports your body better than six pack abs
When people think of the “core,” they often picture six-pack abs or a flat stomach. But the real powerhouse of your core lies deeper — within a group of muscles known as the inner core. It is a deep-seated team of muscles that work together like a 360-degree support system to stabilize your body from the inside out through every move you make. At the center of this team is the transverse abdominis (TrA), a deep abdominal muscle that plays a crucial role in stabilizing your spine and pelvis.
What makes up the inner core?
Your inner core is made up of four key muscles that work together to provide stability and support:
- Diaphragm: The “lid” of your core; this primary breathing muscle sits 360 degrees under the ribs. It is the leader of the team and is why we can use breathwork to train the core.
- Transverse Abdominis (TrA): The “corset” muscle that wraps around your torso to provide deep abdominal support. This is probably the most well known core muscle, but does not work in isolation.
- Pelvic Floor Muscles: The “base” of your core; these muscles support your organs and have a large role in managing internal pressure. This group is often talked about separate from the core, but is an essential part of the equation.
- Multifidus: The “stabilizers” along your spine that work between individual vertebrae. They are small but mighty and can easily get dominated by the other larger back muscles. Targeted small/slow movements are key to activating this part of the core.
These muscles coordinate through breath and gentle activation, creating a stable foundation for movement and posture.
Why is the transverse abdominis so important?
The TrA acts like a built-in back brace. When it’s functioning well, it helps:
- Reduce low back pain by stabilizing the spine.
- Improve posture by supporting the pelvis and rib cage.
- Support pregnancy by managing intra-abdominal pressure and reducing strain on the back and pelvic floor.
- Manage pelvic floor dysfunction such as incontinence, prolapse, and pelvic pain.
When the TrA is weak or not activating properly, other muscles may compensate, leading to pain, poor movement patterns, and dysfunction.
Breathing and core activation: a natural connection
Proper breathing is the gateway to activating your inner core. When you inhale deeply, your diaphragm contracts and moves downward, allowing your lungs to expand. This gentle pressure also expands and lengthens the pelvic floor and TrA. As you exhale, the TrA and pelvic floor naturally contract, helping to stabilize your spine.
Try this simple breathing drill:
- Sit or lie down comfortably.
- Inhale through your nose, allowing your belly and ribs to expand.
- Exhale slowly through your mouth, gently drawing your belly button toward your spine.
- Feel the subtle engagement of your lower abdomen and pelvic floor.
This is the foundation of core activation through breath — a powerful tool for improving function and reducing pain.
Master your movement: inner core exercises
To move from awareness to strength/stability, incorporate these foundational exercises into your routine. Focus on quality of movement and breath rather than speed and force. You should not “brace” your core by sucking it in or pressing your back flat. Your spine should stay neutral, which is a small curve with space between your spine and the ground. This will vary per person, so settle into what feel comfortable.
Exercise | How to Do It | Why It Works |
Supine Marching | Lie on your back with knees bent. While maintaining a neutral spine (small gap between back and the floor), slowly lift one foot off the floor and lower, then repeat on the other, as if marching in slow motion. | Challenges the entire inner core to stabilize your pelvis against the weight of your moving legs. |
Supine Bridges | Lie on your back and lift your hips toward the ceiling while squeezing your glutes, keeping natural spine position. Don’t scoop your pelvis or “suck in” your tummy. | Integrates the inner core with the posterior chain (glutes and back) for functional stability. |
Dead Bug | Lie on your back with arms reaching up and legs in 90/90 position. Slowly lower the opposite arm and leg toward the floor while keeping your back in natural curve. Do not “suck it in” or push back flat. | The ultimate test of core coordination, teaching your center to stay controlled while your limbs move independently. |
Supine marching
Lie on your back with knees bent. While maintaining a neutral spine — a small natural gap between your low back and the floor — slowly lift one foot off the floor and lower it, then repeat on the other side, as if marching in slow motion.
Why it works: Challenges the entire inner core to stabilize your pelvis against the weight of your moving legs.
Supine bridges
Lie on your back and lift your hips toward the ceiling while squeezing your glutes, keeping your spine in its natural position. Don’t scoop your pelvis or suck in your tummy.
Why it works: Integrates the inner core with the posterior chain — your glutes and back — for functional stability.
Dead bug
Lie on your back with arms reaching up and legs in a 90/90 position. Slowly lower the opposite arm and leg toward the floor while keeping your back in its natural curve. Do not suck it in or press your back flat.
Why it works: The ultimate test of core coordination, teaching your center to stay controlled while your limbs move independently.
Why inner core coordination matters
The TrA doesn’t work alone. When the entire inner core functions as a unit, it should be “activated” rather than “braced” — that distinction is what allows for real movement and control. Proper coordination helps the whole system support your body by:
- Reducing low back pain by offloading pressure from the spine and supporting movement.
- Improving posture by providing a stable foundation for the ribs and pelvis.
- Managing pelvic floor dysfunction like incontinence or prolapse by balancing internal pressure.
Who needs inner core training?
Everybody. Inner core training is a pillar of recovery across many stages of life. For postpartum individuals, it is the first step in supporting diastasis recti and regaining pelvic integrity. Those dealing with incontinence find that a responsive core system provides the necessary support to prevent leaks during daily activities and exercise. During perimenopause and menopause, a decrease in estrogen can lead to symptoms that can be addresses with core and pelvic floor training. For persistent back pain, learning to use the core without bracing provides the internal stability needed to move in a more supported way. Even athletes benefit — a well-trained inner core transfers power more efficiently and decreases overall fatigue.
💡 The Bigger Picture
Did you know that your jaw, your feet, and your breathing are all deeply connected to your core and pelvic floor?
Discover how these systems work together — and find the missing pieces to your health puzzle — in our comprehensive resource hub: Your Guide to Core and Pelvic Health.
Frequently asked questions about your inner core and transverse abdominis
What’s the difference between the inner core and the outer core?
The “outer core” (like the rectus abdominis and obliques) is designed for movement and power. The “inner core” is designed for stability and endurance; it stays active at a low level all day to support the whole body.
How does the inner core connect to the pelvic floor?
Think of your core as a pressurized canister. The diaphragm is the lid, the pelvic floor is the base, and the transverse abdominus and multifidi are the wrap. They must work together; if the “lid” or “wrap” pushes too hard without the “base” responding, it can lead to pelvic floor strained weakness or being to tight.
How do I know if my inner core is weak?
Common signs include persistent lower back or hip pain, “doming” or bulging of the stomach during exercise, poor balance, leaking urine when you sneeze, cough, or jump, pelvic pain, or even persistent foot pain.
Can anyone do these exercises, or are there contraindications?
These exercises are generally safe for most, but individuals with acute disc herniations, severe pelvic pain, or those recently post-surgery should consult a physical therapist. Always stop if you feel sharp, shooting pain.
Ready to Strengthen Your Core from the Inside Out?
Discover how physical therapy can help you activate your transverse abdominis and build a strong, stable foundation. Whether you’re recovering from pain, preparing for pregnancy, or just want to move better — our experts are here to guide you.
