The Asymmetrical Tonic Neck Reflex (ATNR) is a primitive reflex present in newborns that aids early motor development. It emerges around 18 weeks in utero, helps during vaginal birth by enabling a "corkscrew" motion through the birth canal, and typically integrates by 6 months of age.
## Mechanism
Turning the head to one side triggers the arm and leg on the face side to extend, while the opposite limbs flex, resembling a fencer's pose. This links head movement with eyes and limbs, stimulating the vestibular system.
## Developmental Role
ATNR supports hand-eye coordination, binocular vision, midline crossing, and bilateral awareness, laying groundwork for crawling and reaching. Retained beyond 6 months, it may contribute to issues like poor handwriting, reading difficulties, ADHD symptoms, or coordination challenges.
