How a Few Milliseconds of Studies Broke Physical Therapy’s Back

Physical therapy spent decades convincing people their backs were fragile because of a handful of studies on:

• delayed multifidus timing

• transverse abdominis activation

• fatty infiltration

• “core stability”

A few EMG studies and some MRI scans somehow snowballed into an entire industry built around:

• abdominal hollowing

• neutral spine dogma

• motor control rituals

• fear of bending

• “glute activation”

• “core dysfunction”

And honestly?
The profession still hasn’t fully recovered from it.

The Studies That Started It

In the 1990s, researchers like Paul Hodges and Carolyn Richardson published influential studies showing that people with low back pain demonstrated altered timing of trunk muscles during movement tasks.

The famous findings:

• delayed transverse abdominis activation

• altered multifidus timing

• changes in anticipatory muscle recruitment

Then later MRI studies by researchers like Julie Hides and others showed:

• multifidus atrophy

• side-to-side asymmetry

• fatty infiltration in people with chronic low back pain

That should have led to a cautious conclusion:

“Pain changes motor behavior and muscle morphology.”

Instead rehab culture turned it into:

“Your spine is unstable because your core muscles are broken.”

That leap was catastrophically damaging.

The Multifidus Became a Cult

The lumbar multifidus became the sacred cow of spinal rehab.

Clinicians became obsessed with:

• palpating tiny spinal muscles

• teaching isolated contractions

• finding “deep stabilizer dysfunction”

• correcting microscopic timing differences

Patients were told:

• their multifidus was shut off

• their stabilizers were not firing

• their core was asleep

• their spine was unstable

All because a muscle activated milliseconds later during a lab task involving arm raises and EMG electrodes.

Meanwhile actual humans outside the lab were:

• lifting furniture

• carrying kids

• playing sports

• working construction

• flexing and rotating their spine constantly

The gap between research interpretation and real-world movement became absurd.

Then Came Fatty Infiltration Panic

Next MRI studies found fatty infiltration in lumbar extensors and multifidus muscles.

And the rehab world lost its mind.

Suddenly every MRI finding became proof that:

• stabilizers were degenerating

• backs were failing

• spinal control systems were collapsing

But here’s the part people ignored:

Fatty infiltration is associated with:

• aging

• inactivity

• reduced loading

• deconditioning

• body composition

• persistent pain states in general

And many asymptomatic people show similar imaging changes.

Because human tissues adapt to life.

That does not prove:

• the multifidus caused the pain

• the spine is unstable

• isolated activation restores normal function

But nuance doesn’t sell continuing education seminars.

Fear does.

Pain Changes Movement — That’s Normal

When people hurt, the nervous system adapts.

That can mean:

• stiffness

• guarding

• altered coordination

• reduced variability

• co-contraction

• timing changes

That is not automatically pathology.

It is often protection.

The nervous system constantly modifies movement based on:

• threat perception

• prior injury

• fatigue

• stress

• confidence

• pain sensitivity

• context

But rehab culture pathologized normal adaptation.

Every altered muscle pattern became:

Dysfunction requiring correction!

The Neutral Spine Disaster

This research directly fueled the “neutral spine at all costs” era.

Suddenly:

• flexion was dangerous

• discs were fragile

• bending was harmful

• spinal motion needed protection

Patients were taught to:

• brace before moving

• avoid lumbar flexion

• hinge for everything

• fear rounding their back

• maintain perfect alignment constantly

People literally started hip hinging to unload dishwashers.

Meanwhile the lumbar spine evolved to:

• flex

• extend

• rotate

• adapt to load

Human spines are adaptable structures.
Not Jenga towers.

The Glute Craze Made It Worse

Then the rehab world discovered “glute inhibition.”

Now apparently:

• weak glutes caused back pain

• weak glutes caused knee pain

• weak glutes caused posture problems

• weak glutes probably caused the fall of Rome

So people with already stiff, guarded systems were told to:

• squeeze harder

• brace harder

• stabilize harder

More co-contraction.
More rigidity.
More hypervigilance.

The exact opposite of what many persistent pain patients actually needed.

What Actually Helps Most Back Pain?

Usually the boring stuff:

• graded exposure

• strength training

• conditioning

• sleep

• confidence

• movement variability

• reduced fear

• load tolerance

• returning to normal activity

Not spending 45 minutes trying to isolate your deep multifidus while breathing into a balloon, a blood pressure cuff under your back, visualizing your pelvic floor, while your PT tells you you’re doing it wrong.

The Biggest Damage Was Psychological

The worst part wasn’t the exercises.

It was the messaging.

Patients were taught:

• their spine was unstable

• their core was defective

• bending was dangerous

• movement needed constant control

• pain meant damage

That creates anxiety and hypervigilance.

And hypervigilance is one of the most reliable ways to keep pain persistent.

The Irony

The original researchers were often careful and nuanced.

The actual studies mostly showed:

• altered timing

• altered recruitment

• muscle adaptation in pain states

That’s it.

But the rehab industry took a few EMG studies and MRI findings and built an entire ideology around them.

An ideology that convinced millions of people their backs were fragile because one tiny spinal muscle fired 50 milliseconds late during an arm raise in a laboratory.

That may be one of the biggest overreactions in rehab history.

-the pissed-off PT- tell me your thoughts, ideas for future articles, share to another PT-

References

1. Paul Hodges, & Carolyn Richardson (1996). Inefficient muscular stabilization of the lumbar spine associated with low back pain: A motor control evaluation of transversus abdominis. Spine, 21(22), 2640–2650. (PubMed)

2. Paul Hodges, & Carolyn Richardson (1998). Delayed postural contraction of transversus abdominis in low back pain associated with movement of the lower limb. Journal of Spinal Disorders, 11(1), 46–56. (PubMed)

3. Paul Hodges (1999). Altered trunk muscle recruitment in people with low back pain with upper limb movement at different speeds. Archives of Physical Medicine and Rehabilitation, 80(9), 1005–1012. (ScienceDirect)

4. G Lorimer Moseley, Paul Hodges, & Simon Gandevia (2002). Deep and superficial fibers of the lumbar multifidus muscle are differentially active during voluntary arm movements. Spine, 27(2), E29–E36. (PubMed)

5. David MacDonald, G Lorimer Moseley, & Paul Hodges (2011). Feedforward activation of the deep fibres of the lumbar multifidus is delayed in chronic unilateral low back pain. (ResearchGate)

6. Peter Kjaer, Bendix, T., Sorensen, J. S., Korsholm, L., & Leboeuf-Yde, C. (2007). Are MRI-defined fat infiltrations in the multifidus muscles associated with low back pain? BMC Medicine, 5(2). (PMC)

7. D’hooge, R., et al. (2012). Increased intramuscular fatty infiltration without differences in lumbar muscle cross-sectional area during remission of unilateral recurrent low back pain. Manual Therapy, 17(6), 584–588. (ScienceDirect)

8. Wong, A. Y. L., et al. (2014). Do changes in transversus abdominis and lumbar multifidus features predict outcomes in people with chronic low back pain? The Journal of Pain. (ScienceDirect)

9. Ansari, B., et al. (2019). Lumbar muscle activation pattern during forward and backward movements in patients with chronic low back pain. (PMC)

10. Paul Hodges et al. (2019). Changes in structure and function of the back muscles in low back pain: Different time points, observations, and mechanisms. Journal of Orthopaedic & Sports Physical Therapy. (JOSPT)

11. Matheve, T., et al. (2023). The role of back muscle dysfunctions in chronic low back pain: State-of-the-art and clinical implications. Journal of Clinical Medicine. (MDPI)

12. Stokes, I. A. F., et al. (2011). Abdominal muscle activation increases lumbar spinal stability: Analysis of biomechanical mechanisms. Clinical Biomechanics. (ScienceDirect)

13. Selkow, N. M., et al. (2017). Transversus abdominis activation and timing in persons with chronic low back pain. (PMC)

14. Teichtahl, A. J., et al. (2015). Fat infiltration of paraspinal muscles is associated with low back pain, disability, and structural abnormalities in community-based adults. The Spine Journal. (Nature)

15. Paul Hodges, Tsao, H., & MacDonald, D. (2010). Motor training of the lumbar paraspinal muscles induces immediate changes in motor coordination in recurrent low back pain. The Journal of Pain. (ScienceDirect)