How long is the Tonic neck reflex expected to be present in infants?

The tonic neck reflex, also known as the asymmetric tonic neck reflex (ATNR), is a primitive reflex that is typically observed in infants. This reflex usually appears at around 1 to 2 months of age and is present until approximately 3 to 4 months of age.

During this time, if the infant's head is turned to one side, the arm and leg on that side extend while the opposite arm and leg flex. This reflex is a significant part of the infant's motor development and helps in establishing their ability to reach and grasp as they grow.

The expected duration of the tonic neck reflex being present until about 3 to 4 months aligns with normal developmental milestones. After this period, the reflex usually diminishes as the infant's voluntary motor control begins to develop. This transition is crucial for further advancement in motor skills and coordination.