3 Signs Your Deep Core Isn’t Working (And What To Do About It)

Your core isn’t just the “six-pack” muscles at the front of your body. It wraps around your entire mid-torso and plays a crucial role in stabilising your spine and maintaining optimal alignment of your pelvis as you move.

But like anything in the body, it doesn't operate in isolation.

Your deep core works in synergy with your glutes and hamstrings to keep the pelvis neutral and your spine supported.

When those deep core muscles aren't working well — whether from injury, overwork, pregnancy, bloating, inflammation, surgery, or accumulated stress — the rest of your body starts compensating.

And that’s when problems begin.

Below are three common signs your core isn’t doing its job… and what you can do to fix it.

1. Your Hamstrings Always Feel Tight

For optimal and efficient movement, your pelvis needs to stay in a neutral position relative to your spine, this is your deep core's main job. When it stops doing this well, other muscles jump in to help — and first up usually the hamstrings.

Because of their attachments at the pelvis, the hamstrings try to prevent the pelvis tipping forward into an anterior tilt.

But that’s not their main job.

So they become overworked, taut, and constantly “tight.”
And no matter how much you stretch them, they never truly release.

Often the issue isn’t that the hamstrings need more length — it’s that the core needs to switch back on. When the deep core activates properly, the nervous system redistributes the workload, and the hamstrings can finally relax and do their job properly.

This is why assessments are essential: many people are stuck in a cycle of overstretching, when what they actually need is better core activation and hamstring strength, not more flexibility.


2. Abdominal Pooching or “Doming” During Exercise

If your belly domes, rises, or pushes outward during crunches or any flexion exercise, this is a clear sign your deep core isn’t stabilising the spine.

Most gym exercises target the outer abdominal muscles (like the rectus abdominis), but fail to integrate the deeper stabilisers:

  • Transverse abdominis (TVA)
  • Pelvic floor
  • Diaphragm

When these deeper layers aren’t working, the outer muscles dominate and push the belly outward.
This creates excessive pressure inside the abdomen and can:

  • Destabilise the lumbar vertebrae
  • Contribute to disc misalignment
  • Irritate the sciatic nerve
  • Aggravate SI joint pain
  • Increase downward pressure on the pelvic floor

That last point is particularly important: unmanaged abdominal pressure can increase the risk of pelvic-floor dysfunction and even pelvic-organ prolapse.

Doming is your body telling you that the inner unit isn’t doing its job.


3. Lower Back Aches or Fatigue

Your deep core — the TVA, diaphragm, pelvic floor, and deep spinal stabilisers — connects directly into the fascial and muscular layers surrounding the lumbar spine.

When these muscles aren’t working well, several things happen:

The diaphragm loses its natural movement, increasing tension around the lumbar spine

The TVA fails to support the vertebrae, reducing segmental stability.

The erector spinae and other back muscles take over to hold you upright.

This leads to muscle fatigue, tightness, compression, poor alignment, and eventually disc irritation or nerve pain.

Most lower-back aches aren’t due to “weakness” in the back — they’re a symptom of a deep core that isn’t stabilising the spine properly.

What To Do About It: Reconnect Your Deep Core

This is where the Pelvic Pro Core Trainer comes in.

It allows you to assess how well your transverse abdominis is activating, measure improvements over time, and follow a structured conditioning program to rebuild deep-core function safely.

Because these muscles are stabilisers, not movers — they need endurance, coordination, and consistent activation through daily movement.

If any of the signs above sound familiar, we highly recommend getting a Pelvic Pro Core Trainer and trying it our for 30 days.

Most people feel and see changes well before the 30-day mark.

And if you want personalised support, reach out anytime. We’re always happy to help guide your progress.

For deeper one-on-one assessment, we recommend finding a CHEK Practitioner or a physiotherapist who understands the biomechanics of the deep core and its role in functional movement. Remember:

If you’re not assessing, you’re guessing.

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