Written by Aparna Hari
Reflexes are spontaneous and involuntary actions of our body that occur without thinking. They are important for our survival as sometimes we need to act immediately without thinking. Babies are born with some primitive reflexes such as the Moro reflex, rooting reflex, and sucking reflex that helps them to survive immediately after birth. Some reflexes stay for the entire life such as the corneal reflex, the cough reflex, etc. Other reflexes related to development appear and disappear at particular stages of development. Symmetric Tonic Neck Reflex in babies is one such reflex you will notice just before they learn how to crawl.
Symmetric Tonic Neck Reflex or STNR is extremely important for your baby’s motor development. It is important to know about STNR to measure the progress your baby shows from infancy to toddlerhood. This is because a delayed STNR and a retained STNR both can negatively impact the growth of your baby.
In This Article
STNR or Symmetric Tonic Neck Reflex is the simultaneous movement of bending and stretching of the limbs of the baby with respect to the neck and head movements. In this developmental reflex, the arms of the baby bend and the legs stretch when they move their heads near their chest. On the contrary, their arms stretch and their legs bend when they move their head backward or away from their neck. This reflex helps babies learn to move the upper and lower parts of their body independently of each other.
Symmetric Tonic Neck Reflex is not a primitive reflex. It is a transitional reflex that occurs in babies when they are between 6 to 9 months and disappears during 11 months. The STNR reflex plays a vital role in initiating the major milestone of crawling in your baby. It prepares your baby to move their upper and lower extremities independently but with synchronization. This rhythmic movement of the limbs along with the head is necessary for crawling. That is why this reflex is also termed the crawling reflex.
STNR appears naturally when the baby successfully integrates two primitive developmental reflexes
TLR enables babies to control their necks and heads against gravity, whereas ATNR develops their gross and fine motor skills.
As a result of their successful integration, STNR appears, which takes the motor development of your baby to the next stage.
The symptoms of STNR will appear in your baby between 6 to 9 months. You can confirm that your baby reaches the STNR stage by observing the following symptoms
For confirming STNR you can do a quick STNR test on your baby.
To test Symmetric Tonic Neck Reflex in your baby you will have to do the following steps
STNR integration occurs when your baby’s brain develops enough to inhibit this involuntary reflex as a voluntary action.
Generally, STNR integration occurs in babies from 9 to 11 months. After the STNR integration babies will be able to move their arms and legs separately or unitedly according to their will.
You can aid in the SNTR integration by increasing the tummy time for your baby. According to a study published in Pediatrics, tummy time positively impacts gross motor skills and overall development. Placing movable and attractive toys around your baby can also enhance neck and body movement.
[Read : Tummy Time For Babies- A Must Do]
In ATNR or Asymmetric Tonic Neck Reflex, the right hands of babies stretch out and the left hands bend if they turn their head towards the right side and vice versa. ATNR is a primitive reflex that disappears in between 5 to 7 months.
According to a report published in Sage Journals, STNR or Symmetric Tonic Neck Reflex emerges only after the proper integration of the ATNR. Though these two reflexes are distinct from each other their purpose is the same.
Both ATNR and STNR help in developing fine and gross motor skills, direction discrimination ability, and hand-eye coordination in the baby.
In general, the Symmetric Tonic Neck Reflex disappears when babies start standing and walking on their own. So STNR should not be present by the time your baby gets one year old.
According to the study published in Europe PMC, in case if a baby has STNR after 12 months then it is termed Retained STNR which indicates delayed motor development that can lead to complications such as
Some of the long-term side effects of retained STNR are;
[Read : W-Sitting Position In Children]
As both the delayed and retained STNR can cause development hazards it will be wise to consult your doctor if you suspect any of them.
You need to see a doctor for SNTR in case
So, the Symmetric tonic neck reflex in babies is a vital but temporary reflex that helps them to separately move their upper and lower extremities at a time. Timely integration of this reflex is important for the healthy development of your baby. You can aid in the process of STNR integration by helping your baby to move forward using different attractive tools. Feel free to talk to your doctor about any doubts you have regarding the reflexes in your baby.
[Read : Developmental Delays in Babies]
Generally, tonic neck reflex will last for up to 5 to 7 months in babies. The tonic neck reflex and the Moro reflex can both be present on both sides of the body equally.
Yes, the Symmetric tonic neck reflex helps your baby to make a transition from the lying position towards the first crawling. However, a retained STNR can indicate a developmental delay and may result in further complications in babies with special needs.
Her experience in impactful writing combined with her background in Home Sciences makes Aparna the perfect candidate for content writing in the pregnancy and parenting niche.Read more.
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