The ATNR (Asymmetrical Tonic Neck Reflex): What It Is, Signs of Retention, and How to Support Coordination, Learning, and Nervous System Maturity


The Asymmetrical Tonic Neck Reflex (ATNR) is an early developmental reflex that supports hand–eye coordination and rolling in infancy. When retained beyond 4–6 months of age, it can contribute to poor posture, difficulty crossing the midline, handwriting fatigue, coordination challenges, and reduced focus. Nervous system-focused chiropractic care may help support improved motor control and regulation.

The Asymmetrical Tonic Neck Reflex (ATNR) is a crucial early-life reflex that supports hand–eye coordination, rolling, and early movement development. When it integrates on time, it allows the left and right sides of the body to work independently and efficiently—an essential foundation for crawling, walking, reading, writing, and sport.

When ATNR does not integrate, however, it can quietly interfere with coordination, posture, attention, learning, and daily tasks, often persisting into the teen and adult years.

At Nomad Chiropractic, we frequently assess retained ATNR patterns in babies, children, teens, and adults across Sydney’s North Shore and Northern Beaches, particularly in those with learning challenges, poor handwriting endurance, clumsiness, or postural asymmetry.


What Is the ATNR?

The ATNR appears around birth and is controlled by the brainstem. It is activated when the baby’s head turns to one side.

The classic ATNR response (often called the fencing posture) looks like this:

  • The arm and leg on the face side extend

  • The arm and leg on the skull side flex

This reflex plays an important role in early development by helping a baby:

  • Develop muscle tone

  • Coordinate eye and arm movement

  • Begin rolling and early reaching

  • Prepare the body for bilateral movement

When Should the ATNR Integrate?

The ATNR should integrate by approximately 4–6 months of age, as voluntary control and midline stability develop.

When integrated, the nervous system can:

  • Cross the midline easily

  • Use both sides of the body independently

  • Coordinate eyes and hands efficiently

  • Maintain symmetrical posture

If the reflex remains active, head movement can continue to drive limb movement reflexively—interfering with coordinated tasks.

Why a Retained ATNR Matters

A retained ATNR means the nervous system struggles to separate head movement from arm and leg movement.

This can lead to:

  • Difficulty crossing the midline

  • Poor bilateral coordination

  • Fatigue during desk or writing tasks

  • Postural asymmetry

  • Reduced efficiency in sport and movement

These challenges are often misinterpreted as clumsiness, lack of focus, or learning difficulty, rather than being recognised as a neurological integration issue.

Signs and Symptoms of a Retained ATNR

In Babies

  • Difficulty rolling both ways

  • Preference for turning the head to one side

  • Asymmetrical movement patterns

  • Challenges with tummy time

In Children

  • Poor handwriting or writing fatigue

  • Difficulty copying from the board

  • Trouble crossing the midline

  • Awkward pencil grip

  • Poor ball skills

  • Restlessness at a desk

In Teens

  • Neck and shoulder tension during study

  • Poor posture at a desk

  • Reduced coordination in sport

  • Difficulty multitasking

  • Fatigue with prolonged sitting

In Adults

  • Neck and upper back tension

  • Poor posture during desk work

  • Reduced coordination or balance

  • Difficulty with tasks requiring left–right integration

  • Chronic fatigue with fine motor tasks

Many adults are surprised to learn that long-standing posture or coordination issues may be linked to a retained ATNR.

How the ATNR Affects the Nervous System

When the ATNR remains active:

  • Turning the head reflexively changes muscle tone

  • The body struggles to stabilise at midline

  • Postural muscles fatigue quickly

  • Higher brain centres must work harder to override reflexive movement

This can interfere with:

  • Writing and reading efficiency

  • Eye-hand coordination

  • Postural endurance

  • Focus and learning

Over time, these inefficiencies increase physical and mental effort for everyday tasks.

Home Care Strategies to Support ATNR Integration

Professional assessment is essential, but consistent home support greatly improves outcomes.

1. Encourage Cross-Midline Movement

  • Crawling and bear crawls

  • Cross-body games (right hand to left knee)

  • Ball games that require tracking and reaching

2. Support Good Desk Posture

  • Feet flat on the floor

  • Paper positioned slightly angled

  • Regular movement breaks

3. Reduce Compensatory Patterns

  • Avoid sitting on one leg or twisting at a desk

  • Encourage symmetrical sitting and standing

4. Reflex-Based Movement Exercises

Specific ATNR-focused movements can help the nervous system learn to stabilise without reflexive responses. These exercises should be:

  • Slow

  • Controlled

  • Symmetrical

  • Practised consistently

(Always follow guidance from a trained professional.)

Chiropractic Care and the ATNR

Chiropractic care supports ATNR integration by optimising spinal, cervical, and nervous system communication.

At Nomad Chiropractic, our approach includes:

  • Gentle, nervous-system-focused chiropractic adjustments

  • Support for cervical spine and postural input to the brain

  • Movement and coordination assessment

  • Age-appropriate techniques for babies, children, teens, and adults

  • Integration of targeted home reflex exercises

This approach is particularly valuable for:

  • Children with learning or handwriting difficulties

  • Teens with postural fatigue or sporting challenges

  • Adults with desk-related neck tension and coordination issues

Families across Sydney’s North Shore and Northern Beaches often seek us out for this developmental and neurological focus.

Why Early Support Matters

When the ATNR remains active:

  • Learning tasks require more effort

  • Postural asymmetries become habitual

  • Coordination challenges persist

Early identification can:

  • Improve handwriting and learning efficiency

  • Support balanced posture

  • Enhance coordination and confidence

That said, integration is still possible later in life, and many adults experience meaningful improvements once this reflex is addressed.

Frequently Asked Questions

1. Can ATNR affect handwriting and learning?

Yes. Retained ATNR is commonly linked to handwriting fatigue, difficulty copying, and poor coordination at a desk.

2. Is poor coordination always caused by ATNR?

Not always—but ATNR is a frequently overlooked neurological contributor.

3. How long does integration take?

This varies by age and nervous system stress. Many people notice improvements within weeks to months or even longer for some with consistent care.

The ATNR is meant to help us move and learn—not hold us back.

If you or your child struggle with posture, coordination, learning tasks, or desk-based fatigue, a retained ATNR may be part of the picture.

At Nomad Chiropractic, we focus on nervous system-focused chiropractic care, supporting primitive reflex integration for families across Sydney’s North Shore and Northern Beaches, while educating families worldwide.


Homecare Movement Tips

We have a lot of homecare tips on our website here. But before you start doing every exercise under the sun we recommend getting checked and adjusted because some may integrate without the need of an extensive home-care regime with chiropractic care.

📲 FOLLOW SANDY ON SOCIALS! She gives heaps of Homecare intentional movement tips.
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A retained ATNR can quietly affect posture, coordination, handwriting endurance, and learning efficiency long after infancy. When head movement continues to drive reflexive limb responses, everyday tasks require more effort. Supporting neurological integration through targeted movement strategies and nervous system-focused chiropractic care may help improve stability, midline control, and resilience.

At Nomad Chiropractic, we focus on nervous system-based chiropractic care, supporting reflex integration for families across Sydney’s North Shore and Northern Beaches, and educating families worldwide.

Want to learn more? Book a FREE 15min discovery call with one of our North Shore Paediatric & Retained Primitive Reflex Chiropractors today: Book HERE

 

👉 Book a nervous system assessment today and take the first step toward calmer, more resilient living.

      • Goddard Blythe, S. Reflexes, Learning and Behaviour. Fern Ridge Press.

      • Goddard Blythe, S. Attention, Balance and Coordination. Wiley-Blackwell.

      • Melillo, R. Disconnected Kids. Penguin Random House.

      • Ayres, A. J. Sensory Integration and the Child. Western Psychological Services.

      • Porges, S. The Polyvagal Theory. W. W. Norton & Company.

      • Schore, A. Affect Regulation and the Origin of the Self. Routledge.

      • Kolb, B., Gibb, R. “Brain plasticity and behaviour.” Annual Review of Psychology.

      • Teicher, M. H. et al. “The neurobiological consequences of early stress.” Biological Psychiatry.

      • Australian Spinal Research Foundation – Neurological development and posture resources.

      • Haavik, H. The Reality Check.

      • International Chiropractic Pediatric Association (ICPA) Developmental Guidelines.

      • Panksepp, J. Affective Neuroscience. Oxford University Press.

  • The information provided by Nomad Chiropractic is intended for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

    Chiropractic care, movement strategies, and nervous system–based approaches aim to support overall function and wellbeing. They do not diagnose or treat medical conditions, learning disorders, behavioural conditions, or developmental diagnoses.

    Every child is unique, and responses to care may vary. Any concerns regarding your child’s health, development, learning, or behaviour should be discussed with a qualified healthcare professional. Always seek advice from your GP, paediatrician, or other appropriately registered health practitioner regarding specific medical concerns.

    This content does not replace individual assessment or care. Decisions about your child’s health should be made in consultation with qualified professionals familiar with your child’s individual needs.

If posture, handwriting, or coordination feel harder than they should, a retained ATNR may be part of the picture—book a nervous system assessment to explore supportive next steps.

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The Grasp Reflex (Palmar & Plantar): What It Is, Signs of Retention, and How to Support Fine Motor Skills, Posture, and Nervous System Development

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The TLR (Tonic Labyrinthine Reflex): What It Is, Signs of Retention, and How to Support Balance, Posture, and Nervous System Regulation