Asymmetric tonic neck reflex

Asymmetric tonic neck reflex

The asymmetric tonic neck reflex (ATNR) is a primitive reflex that is typically observed in newborns and infants. It is elicited by turning the baby’s head to one side, causing the limbs on the face side to extend and the limbs on the skull side to flex.

Here are some key characteristics and implications of the asymmetric tonic neck reflex:

  1. Stimulus: The ATNR is triggered by the movement of the head. When the baby’s head is turned to one side, the reflex is elicited.
  2. Limb movements: When the head is turned to one side, the arm and leg on that side of the body will extend, while the arm and leg on the opposite side will flex. This gives the appearance of a “fencing” position.
  3. Developmental significance: The ATNR is considered a primitive reflex that emerges in the early stages of fetal development. It helps with the development of body awareness and motor control.
  4. Integration: The ATNR normally starts to diminish between 4 and 6 months of age and is typically fully integrated by 6 to 9 months. As the baby develops more mature motor control, the reflex should fade away.
  5. Impact on motor skills: The ATNR can affect the baby’s ability to coordinate movements on both sides of the body. It may temporarily hinder activities such as reaching, crawling, and hand-eye coordination.

It’s important to note that the presence or persistence of the asymmetric tonic neck reflex beyond the expected developmental timeframe may indicate an issue with motor development or neurological functioning. If you have concerns about your child’s reflexes or motor skills, it’s recommended to consult with a healthcare professional, such as a pediatrician or pediatric neurologist, for proper evaluation and guidance.