The STNR (Symmetrical Tonic Neck Reflex): What It Is, Signs of Retention, and How to Support Posture, Focus, and Coordination
The Symmetrical Tonic Neck Reflex (STNR) is a developmental reflex that helps babies transition into crawling. When retained beyond infancy, it can contribute to poor posture, difficulty sitting still, handwriting fatigue, coordination challenges, and reduced focus. Nervous system-focused chiropractic care may help support improved postural control, motor coordination, and regulation at any age.
The Symmetrical Tonic Neck Reflex (STNR) is a key developmental reflex that helps babies transition from lying on the floor to crawling—and eventually to standing, walking, and coordinated movement. When it integrates on time, it supports good posture, efficient movement, and healthy learning patterns.
When it doesn’t, however, the STNR can quietly interfere with posture, coordination, attention, muscle tone, and school performance, often persisting into the teen and adult years.
At Nomad Chiropractic, we regularly identify retained STNR patterns in children and adults across Sydney’s North Shore and Northern Beaches, particularly in those with poor posture, fatigue when sitting, coordination difficulties, or challenges with focus and learning.
What Is the STNR?
The Symmetrical Tonic Neck Reflex typically emerges between 6–9 months of age, as babies prepare to crawl. It is mediated by the brainstem and spinal cord and is activated by movement of the head in relation to the body.
The reflex works as follows:
When the head bends forward, the arms bend and the legs extend
When the head lifts backward, the arms extend and the legs bend
This pattern helps a baby:
Get onto hands and knees
Separate upper and lower body movement
Develop the coordination needed for crawling
When Should the STNR Integrate?
The STNR should integrate by 9–11 months of age, once crawling becomes smooth and coordinated.
When integrated, the nervous system can:
Maintain upright posture
Sit at a desk without collapsing or fidgeting
Coordinate eyes, arms, and legs independently
Support sustained attention and learning
If the reflex remains active, the body may struggle to separate head, arm, and leg movement—affecting posture and concentration.
Why a Retained STNR Matters
A retained STNR keeps the nervous system relying on reflexive movement patterns rather than voluntary control.
This can lead to:
Poor sitting posture
Fatigue during desk work
Difficulty with handwriting or fine motor tasks
Challenges with reading and focus
Inefficient movement patterns during sport
These issues are often mistaken for laziness, poor motivation, or learning difficulties, rather than being recognised as neurological immaturity.
Signs and Symptoms of a Retained STNR
In Babies
Difficulty transitioning to crawling
Asymmetrical crawling patterns
Poor tolerance for tummy time
Stiff or awkward movement on hands and knees
In Children
Slouching or collapsing at a desk
Sitting on legs or wrapping feet around chair legs
Poor handwriting endurance
Difficulty copying from the board
Reduced concentration
Avoidance of desk-based tasks
In Teens
Poor posture, especially during study
Neck and shoulder tension
Fatigue with prolonged sitting
Reduced coordination in sport
Difficulty multitasking
In Adults
Chronic neck and upper back tension
Postural fatigue at work
Poor core stability
Difficulty separating upper and lower body movement
Reduced tolerance for prolonged desk or screen work
Many adults are unaware that their postural and concentration challenges may be linked to an unintegrated STNR.
How the STNR Affects the Nervous System
When the STNR remains active:
Head movement continues to drive limb movement reflexively
Postural muscles fatigue quickly
The nervous system expends excess energy maintaining position
Higher brain centres struggle to fully take over motor control
This can interfere with:
Postural endurance
Fine motor skills
Eye-hand coordination
Learning efficiency
Over time, these inefficiencies can increase physical and mental fatigue.
Home Care Strategies to Support STNR Integration
While professional assessment is essential, consistent home support is key.
1. Encourage Crawling-Style Movement
Bear crawls
Hands-and-knees play
Tunnel crawling or obstacle courses
These movements help reinforce proper separation of upper and lower body control.
2. Improve Desk Setup
Feet flat on the floor
Desk and chair at appropriate height
Regular movement breaks
3. Support Postural Endurance
Short bursts of sitting with breaks
Core-supportive play (planks, wheelbarrows)
Avoid prolonged static sitting
4. Reflex-Based Movement Exercises
Specific exercises designed to gently re-pattern STNR responses can help the nervous system integrate this reflex. These exercises should be:
Slow
Controlled
Symmetrical
Practised consistently
(Always follow guidance from a trained professional to ensure safety and effectiveness.)
Chiropractic Care and the STNR
Chiropractic care supports STNR integration by improving spinal mechanics, postural input, and brain-body communication.
At Nomad Chiropractic, our approach includes:
Gentle, nervous-system-focused chiropractic adjustments
Postural and movement assessments
Support for spinal and cervical input to the brain
Age-appropriate techniques for babies, children, teens, and adults
Integration of targeted home exercises
This approach is especially helpful for:
Children struggling with posture and school tasks
Teens under study or sporting demands
Adults with desk-related postural fatigue
Families across Sydney, the North Shore, and Northern Beaches often seek us out for this developmental and neurological expertise.
Why Early Support Matters
If the STNR remains active:
Postural inefficiencies become habitual
Learning tasks require more effort
Physical fatigue increases
Early identification can:
Improve posture and sitting endurance
Enhance focus and learning efficiency
Support coordinated movement and sport performance
That said, integration is still possible later in life, and many adults experience noticeable improvements in comfort, posture, and focus once this reflex is addressed.
Frequently Asked Questions
1. Can STNR affect learning and school performance?
Yes. Retained STNR can impact posture, eye-hand coordination, and endurance for desk-based tasks.
2. Is poor posture always a reflex issue?
Not always—but retained STNR is a commonly overlooked neurological contributor.
3. How long does integration take?
This varies by age and nervous system stress, but improvements are often seen within weeks to months or years with consistent care.
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.
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A retained STNR Reflex can quietly affect posture, coordination, sitting endurance, and focus long after infancy. When the nervous system continues to rely on reflex-driven patterns, everyday tasks require more effort. Supporting neurological integration through movement strategies and nervous system-focused chiropractic care may help improve stability, regulation, and motor control at any age.
At Nomad Chiropractic, we specialise in 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.
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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.
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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 you or your child struggle with posture, coordination, or sitting endurance, a retained STNR may be contributing.
Book a nervous system assessment to explore supportive next steps.