Core Dysfunction In Pediatrics: Beyond The Abdominal Musculature

When you think about “core strength” in pediatric rehab, it’s easy to picture planks or stability ball activities. But in clinical practice, you often meet children whose core weakness doesn’t respond to traditional strengthening or stability programs. This isn’t because the kids aren’t working hard enough, but because you may be missing the root of the problem.

Core function is not simply about strong abdominal muscles. The core is the interaction between the pelvic floor, diaphragm and rib cage, abdominal wall and viscera, and the vocal folds. These structures function as a coordinated system to manage pressure systems and postural control.

The involved anatomical structures develop in a predictable sequence during infancy and early childhood. But when something interrupts that sequence, such as developmental delays, prolonged postural habits, or medical history, you may see persistent dysfunction into later childhood. This may present as motor control issues, bowel or bladder dysfunction, or poor balance well into the school years.

In this blog post, you’ll explore how the pelvic floor, diaphragm, and postural systems work together in pediatric development. Then I’ll walk you through a case presentation to show you how addressing these systems can create meaningful change.

Let’s take a brief look at how the core acts as a pressure system. A stable core is not a rigid core. Rather, in order to have optimal core function, there needs to be strength and function between all parts of the system to allow for dynamic, anticipatory responses.

Breathing regulates the reflexive responses to the core to balance and maintain pressure in the system. When a child breathes in, the diaphragm descends, intra-abdominal pressure increases, and the pelvic floor responds with a subtle eccentric movement. When breathing out, the diaphragm rises and the pelvic floor recoils upward. This breath-driven dance supports proper alignment, good postural stability, and motor coordination.

If one link in this chain is tight, weak, or poorly coordinated, the entire system compensates. When working with these kids, identifying and addressing the compensations early will help prevent chronic symptoms.

The pelvic floor is often the missing piece that is overlooked in core work. The role of the pelvic floor is essential in supporting the visceral organs, regulating continence, and stabilizing the pelvis. Let’s explore how your traditional postural assessment skills can be applied to evaluating pelvic floor function in children.

For many pediatric PTs and OTs, the pelvic floor can feel like unfamiliar territory. Yet with children, dysfunction in this area is more common than expected and doesn’t always present as incontinence. It may appear as constipation, encopresis, frequent postural shifting, or even avoidance of physical activity due to discomfort.

The pelvic floor is an integral component of the postural core, working in coordination with the diaphragm, abdominal wall, and deep spinal stabilizers to regulate intra-abdominal pressure and maintain balance during movement.

Postural control in children is influenced by how the rib cage aligns over the pelvis. A flared or compressed rib cage alters both breathing mechanics and pelvic floor activation. Lower rib compression, for example, limits lateral costal expansion during inhalation. A thorax drifting behind the pelvis shifts load onto passive ligamentous structures rather than demanding active muscular support. Forward head posture and rounded shoulders can further inhibit optimal diaphragm excursion.

When rib cage alignment and pelvic floor function are compromised, compensatory strategies often emerge. These patterns may redistribute pressure toward the anterior abdominal wall or pelvic outlet, challenge core stabilization, and perpetuate musculoskeletal and visceral dysfunction.

Recognizing these interconnections during assessment allows you to address the root of a child’s postural and functional challenges, rather than focusing solely on isolated strength deficits. Let’s consider how these patterns may emerge in early childhood and evolve into later years, as illustrated in the upcoming case study.

In infancy, postural control develops alongside the ability to manage breath and pressure. Prone positioning, sitting, quadruped positioning and crawling, and standing are essential opportunities for the diaphragm and pelvic floor to sync with trunk stabilizers. When development is interrupted or delayed, kids may skip key stages of this motor control refinement.

Some early warning signs you can spot in your pediatric practice include:

• Poor endurance for upright sitting
• Breath-holding during fine or gross motor tasks
• Difficulty coordinating breath with speech
• Postures that “hang” on ligaments rather than using muscular support
• Excessive rib flaring, upper chest breathing, or a collapsed rib cage

Left unaddressed, these patterns can persist into later childhood, where they often present as more ingrained postural habits. Furthermore, I encourage you to view these signs not only as indicators of postural control and motor delays, but also as reflections of breathing mechanics and internal organ function and health

Inefficient breathing mechanics may directly interfere with bowel and bladder regulation and additional visceral dysfunction.

To illustrate how early disruptions in core and pressure system coordination can evolve over time, let’s examine the case presentation of a 10-year-old with a long history of constipation and encopresis.

This patient’s history illustrates how interconnected all the systems of the core can be.
*Carson, a 10-year-old boy, presented with chronic constipation and encopresis, both ongoing for seven years.

Observation:

• Breathing Mechanics: Breathing mechanics revealed a wide rib angle in supine, with minimal lateral costal expansion. Movement during respiration occurred primarily anterior-posteriorly.
• Posture: Postural assessment indicated a prolonged “gaming posture” in sitting, characterized by forward head, rounded shoulders, and a collapsed abdominal wall. In standing, Carson hung on passive ligamentous structures with the thorax positioned behind the pelvis and an exaggerated lumbar lordosis. While perfect plumb line alignment is unnecessary, optimal pressure system function requires the thorax and pelvis to be stacked like a cylinder.
• Abdominal Wall: Examination of Carson’s abdominal wall revealed horizontal postural creases in the skin from prolonged slouched sitting. During laughter, pressure distribution was equal above and below the umbilicus, but palpation revealed a visible diastasis rectus abdominis above the umbilicus and increased intra-abdominal pressure due to chronic constipation.
• Core Control: Core control testing demonstrated weak trunk stability and poor balance. Bird dog exercises proved too advanced, as Carson immediately compensated with excessive spinal movement and breath-holding.

The combination of rib cage restriction, inefficient breathing pattern, pelvic misalignment, and abdominal wall abnormality pointed to a dysfunctional pressure system rather than isolated weakness. This impaired overall core function was contributing to Carson’s constipation and encopresis.

Interventions focused on restoring lateral costal expansion, improving rib cage-pelvis alignment, coordinating pelvic floor activation with breath, and building trunk control through core stabilization progressions before advancing to more dynamic tasks.

1. Look Beyond the Abs: A child can have “weak abs” because their breathing and pelvic floor systems aren’t functioning in coordination.
2. Breathing Drives Posture: Diaphragm excursion and rib cage mobility are foundational to upright stability.
3. Pelvic Floor is Part of the Core: Even if you don’t specialize in pelvic health, assessing pelvic alignment and function gives critical insight into pressure management.
4. Posture Habits Matter: Educate families on how daily positions (gaming, homework, lounging) influence long-term musculoskeletal and visceral health.

In pediatric rehab, addressing the core weakness is about restoring a functional, coordinated pressure system that supports the child’s development and quality of life.

That’s exactly what we explore in detail in The Pelvic Floor, Diaphragm, and Core and Their Role in Postural Development (PFDC) course. This introductory course gives PTs and OTs a framework to integrate pelvic floor and breathing systems into postural work, even if pelvic health isn’t your primary specialty.

Join us on September 21, 2025!