What is the symmetrical tonic neck reflex (STNR)?
Reflexes are movements that a person makes involuntarily, without
thinking. You can watch them from the moment your baby is born. There are five
common reflexes you will see in your newborn:
- Rooting reflex — searching for a nipple on a breast or bottle
- Sucking reflex — happens when the roof of the baby's mouth is stimulated
- Grasping reflex — bending the fingers to grab
- Startle reflex — responding to loud noises
- Tonic reflex — happens when the baby lies on their back
The STNR is a reflex that usually appears during the first year of a
child's life. It usually starts to decline by the time they reach 9-10 months.
The terms "
STNR
" and "symmetrical tonic neck reflex" mean the same thing. Your
pediatrician can use any term.
The STNR helps the child learn to move the upper and lower half of the
body independently. The STNR is commonly referred to as the "crawl
reflex" because it allows the baby to move from lying down to standing on
all fours.
You usually notice that your baby goes through this stage between 6 and
9 months of age, when he transitions from lying on the floor or other surface
to crawling.
When your child has reached the STNR stage, you may notice that as his
neck and arms straighten, his legs bend. When the neck and arms are bent, the
legs are straightened. These movements are important for crawling and first
steps.
Why is this reflex so important?
The brain, spinal cord, and nerves make up the nervous system, which
controls the early motor skills that develop during this period. At this stage,
children begin to control their movements.
The STNR is important for the development of posture, hand-eye
coordination and sports.
What is a retained STNR?
The STNR connects the movements of the child's head with the movements
of his arms and legs. If a child retains this reflex, it can cause problems as
they grow. Some possible long-term effects of a persistent STNR:
- Headaches from muscle tension in the neck
- Difficulty writing and reading
- Difficulty sitting still
- Vision problems
- Social and educational delays
Signs of retained STNR include:
- Poor, hunched posture
- Skips crawling and go straight to walking
- “W” sitting, when the knees are in front of the body but the feet are out to the side of the hips
- "Bear walking" or walking on hands and feet
- Difficulty copying from a blackboard
Talking to your pediatrician about
the STNR
Being a parent can be scary and overwhelming. Keep in mind that it is
normal for children to develop at different rates. If you are concerned about
your child's development, it is always a good idea to contact your pediatrician
and let them know about your concerns. If additional steps are needed, your
pediatrician can make recommendations and refer you to a specialist if
necessary.
An easy way to test for a STNR is to use the Developmental Screening
Questionnaire. This screening tool can be used to track the developmental
milestones of a child from one year of age.
The questionnaire cannot be used to predict future neurological
problems, but may be useful in identifying preserved primitive reflexes such as
the STNR.