Which of the following actions by the nurse would elicit the tonic neck reflex?
A.
Holding the newborn upright with feet touching a flat surface.
B.
Stroking the outer edge of the sole of the newborn’s foot up toward the toes.
C.
Turning the newborn’s head to one side while in a supine position.
D.
Clapping hands or making a loud noise near the newborn.
The correct answer and Explanation is :
The correct answer is:
C. Turning the newborn’s head to one side while in a supine position.
Explanation:
The tonic neck reflex, also known as the asymmetric tonic neck reflex (ATNR), is a primitive reflex observed in newborns and young infants. This reflex is an involuntary response that typically emerges within the first few weeks of life and is usually present until about 6 months of age. The tonic neck reflex is a crucial part of neurological development and is used to assess the integrity of the central nervous system.
When a newborn’s head is turned to one side while they are lying on their back (supine position), the tonic neck reflex is triggered. In response to this stimulus, the newborn will extend the arm and leg on the side to which the head is turned, while flexing the arm and leg on the opposite side. This reflex mimics the “fencing position” or “en garde” stance seen in fencing, which is why it is sometimes referred to as the fencing reflex.
Here’s a breakdown of why the other options do not elicit the tonic neck reflex:
A. Holding the newborn upright with feet touching a flat surface: This action typically triggers the stepping or walking reflex, not the tonic neck reflex. The stepping reflex involves the newborn making stepping movements when their feet touch a solid surface.
B. Stroking the outer edge of the sole of the newborn’s foot up toward the toes: This action triggers the Babinski reflex, where the toes fan out in response to the stimulation of the sole. It is not related to the tonic neck reflex.
D. Clapping hands or making a loud noise near the newborn: This action is likely to elicit the startle or Moro reflex, where the infant reacts to sudden loud noises or movements by flinging out their arms and legs and then pulling them back in.
The tonic neck reflex is essential for assessing developmental milestones and neurological health in infants. Its presence and symmetry are important indicators of normal neurological development.