A Parent’s Guide to the ATNR Reflex and Coordination
Written by
The Village Team
Published
Clinically reviewed by
Mary Gianatasio, MA in Child Psychology
Founding Clinical Member
From the moment babies begin developing in the womb, their nervous systems are guided by a series of automatic movement patterns known as primitive reflexes. These reflexes help support early survival, movement, sensory development, and brain organization during infancy.
One of the most important of these early reflexes is the Asymmetrical Tonic Neck Reflex (ATNR). Though often unfamiliar to parents, the ATNR plays a foundational role in coordination, posture, visual tracking, and later learning skills.
Understanding how this reflex develops - and what may happen when it remains active longer than expected - can offer helpful insight into a child’s physical and neurological development.
What Is the ATNR Reflex?
The ATNR begins developing in utero around 18 weeks gestation and is most active between 1–4 months of age. It is sometimes called the “fencer’s pose” reflex because of the body position it creates.
When a baby’s head turns to one side:
The arm and leg on the same side naturally extend
The opposite arm and leg flex inward
This automatic movement pattern helps babies begin organizing movement between the two sides of the body while also supporting early muscle tone, body awareness and visual development.
As the nervous system develops, the reflect is typically integrated between 3-9 months of age, allowing more coordinated and voluntary patterns to emerge.
Why Is the ATNR Important?
Although primitive reflexes are temporary, they serve an important purpose during early development.
The ATNR helps support:
Hand-Eye Coordination
The reflex encourages babies to visually track their hands and movements, helping build the foundation for coordinated reaching, grasping, and later fine motor skills.
Midline Crossing
As development progresses, children gradually learn to move smoothly across the midline of the body - the invisible line dividing left and right sides. This skill is important for:
Reading and writing
Bilateral coordination
Sports and movement patterns
Telling time
Left-right discrimination
Posture and Muscle Tone
The ATNR contributes to early postural organization and body awareness. Primitive reflexes help prepare the nervous system for more advanced balance and movement patterns later in childhood.
Visual Tracking and Learning Readiness
Because the ATNR connects head movement with eye and limb coordination, it may also influence visual tracking skills that support reading and sustained visual attention.
Primitive Reflexes and Nervous System Development
Primitive reflexes are part of the brain’s early motor programming. As children grow, these reflexes are gradually integrated into more refined movement patterns directed by higher brain centers.
This transition supports:
More coordinated movement
Improved sensory processing
Better balance and postural control
Greater motor planning abilities
Increased emotional and behavioral regulation
Researchers describe this process as part of neuropsychomotor maturation - the nervous system’s gradual progression from reflexive movement toward more efficient, voluntary control.
Some reflex-like movement patterns may also appear subtly during periods of increased physical demand or athletic activity, reflecting the nervous system’s ongoing role in posture, balance and movement coordination.
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What Happens if the ATNR Remains Retained?
A primitive reflex that remains active beyond the expected developmental stage is sometimes called a retained reflex.
Some clinicians and developmental specialists associate retained ATNR patterns with challenges involving:
Coordination and balance
Handwriting difficulties
Crossing midline comfortably
Visual tracking or reading fluency
Awkward posture or movement patterns
Difficulty sitting still
Challenges with bilateral motor tasks
It is important to note that retained reflexes themselves are not considered diagnoses and do not necessarily indicate that something is wrong. Rather, they may reflect differences in how the nervous system is organizing sensory and motor information.
Research in this area continues to evolve. A 2025 study involving children aged 5–8 found that ATNR reflex patterns may influence aspects of postural control. It is also important to remember that coordination difficulties, attention challenges, and sensory sensitivities can have many contributing factors and are not caused by primitive reflexes alone.
The Connection Between Movement, Regulation, and Learning
Research increasingly recognizes that movement and sensory development are deeply connected to learning, attention, and emotional regulation.
Children develop through movement. Climbing, crawling, balancing, rolling, reaching, and coordinated play all provide sensory input that helps shape neural pathways involved in attention, body awareness, coordination, and self-regulation.
From an integrative perspective, developmental health is influenced by many interconnected factors, including:
Sleep quality and circadian rhythm regulation
Nutrition that supports brain and nervous system development
Physical movement and outdoor play
Sensory-rich experiences
Emotional safety and attachment
Stress regulation and nervous system support
When these systems are supported together, children are more likely to develop strong foundations for coordination, regulation, resilience, and learning.
Supporting Healthy Reflex Integration
Many of the activities that naturally support childhood development also support reflex integration and nervous system maturation, including:
Tummy time during infancy
Crawling and floor-based play
Climbing and balance activities
Bilateral movement exercises
Outdoor movement and unstructured play
Rhythmic activities like swimming, dancing, or jumping
Some children may also benefit from occupational therapy, physical therapy, developmental therapy, or movement-based support when motor or sensory challenges are present.
When Should Parents Seek Support?
Every child develops at their own pace, and some variation in coordination and movement patterns is completely normal.
However, parents may consider seeking support if a child consistently struggles with:
Coordination or balance
Handwriting or fine motor tasks
Reading tracking difficulties
Sensory sensitivities
Motor planning challenges
Persistent awkward posture or movement
A pediatrician, occupational therapist, developmental specialist, or other qualified healthcare professional can help assess whether additional support may be helpful.
Final Thoughts
The ATNR reflex is one of the nervous system’s earliest movement patterns, helping babies build the foundations for coordination, posture, visual tracking, and motor development.
Primitive reflexes are a normal part of infancy, and their integration reflects the broader maturation of the nervous system over time. Supporting healthy development through movement, sleep, nutrition, sensory experiences, play, and emotional connection can help nurture the foundations that underlie learning, regulation, coordination, and resilience throughout childhood.
References
Murtiningsih, M., Peristiowati, Y., Ellina, A., , N., & Wardani, R. (2025). Effect of ATNR (Asymetrical Tonic Neck Reflexs) Primitive Reflexs on Postural Control and Focus of Children Aged 5-8 Years at the Touch Care Mataram Physiotherapy Clinic. Journal Of Nursing Practice. https://doi.org/10.30994/jnp.v8i2.733.
Arcilla CK, Vilella RC. Tonic Neck Reflex. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559210/
