During normal childhood development, the Asymmetrical Tonic Neck Reflex (ATNR) is present in utero at 18 weeks and is integrated at 4 to 6 months.

ATNR assists in the birthing process as the baby makes its way down the birth canal. It is actually activated and reinforced by the birth process. Note - babies born by Caesarean Section could be at a higher risk for a retained ATNR.

• It is a necessary reflex for survival; the ATNR causes the baby to turn its head when lying on his/her stomach, preventing him/her from lying with their face straight down and obstructing airways.
• The ATNR is crucial to vision development. When a child turns his/her head, reaches and touches an object, near vision is developed. Integration of this reflex allows the child to crawl, further developing distance vision, eye tracking crossing midline, and depth perception.
• It is the basis for auditory development, the right ear advantage for speech and language, and the left for rhythm. It is the foundation for auditory and auditory-visual processing.
• The ATNR is important for the development of differentiation between the right and left sides of the body, allowing the right and left sides to be able to move independent of each other and aids in developing hand dominance.
• If the ATNR persists, the child will be unable to use a cross pattern of movement, resulting in either not being able to crawl, and later, will not be able walk with a cross pattern arm swing.
• The child will want to perform tasks on one side of the body at a time. This also results in hesitancy in moving eyes across the midline, and the child will have difficulty reading.
• When a child turns his head to look at a page, his arm will want to straighten and his fingers open. It requires much effort to override this when the child is holding a pen or pencil and attempting to write, usually at the expense of cognitive processes and short-term memory.

Symptoms of a Retained Asymmetrical Tonic Neck Reflex (ATNR)

• Inability to execute cross-pattern movements, when walking, running, skipping, etc.
• No established hand or foot preference
• Poor handwriting and poor written expression of ideas
• Balance is affected by head turning
• Problems with crossing midline with arms and legs
• Problems with eyes crossing midline, resulting in difficulties with reading
• Difficulty changing eye focus from near to far
• Difficulty learning to ride a bicycle
• ADD and ADHD
• Problems with throwing and catching
• Poor sense of direction
• Letter and number reversals
• Learning difficulties in spelling, math and language
• Poor eve/hand coordination
• Scoliosis
• Dyslexia
• Social and behavioral challenges
• Autism
• Sensory input confusion (eyes, ears and therefore, memory)