Symmetrical Tonic Neck Reflex and SPD

For my last blog we explored the Asymmetrical Tonic Neck Reflex and its connection to sensory processing disorder (SPD). If you missed it you can check it out here. For the next few months I will continue to delve into the most commonly retained primitive reflexes, so keep watching if we haven’t talked about the one you are looking to learn more about! Today’s blog is about STNR (Symmetrical Tonic Neck Reflex). Since sensory processing is what we are all about here at Sensory Sid, I also want to tie in to how these may be connected.

Okay, what is the Symmetrical Tonic Neck Reflex (STNR)? Learn this, what to do for a retained STNR and why it matters for those with SPD (sensory processing disorder). Let’s get familiar with primitive reflexes first.

A quick recap of primitive reflexes is that they are automatic movement patterns that are prompted by a specific stimulus. They are useful during birth and in infancy. As babies grow and develop, these reflexes are “replaced” by tracks of higher level brain and body nervous system communication that result in more refined movement and body use. This is called integration. We call a reflex “retained” if it continues to show up past its expected timeframe. Check out this recent blog if you want to learn even more.

These short periods of primitive reflexes in use are important in a baby’s development and in sensory processing. When reflexes are retained, the nervous system is losing out on opportunities for sensory processing development and other higher level skill development.

What is Symmetrical Tonic Neck Reflex?

Symmetrical Tonic Neck Reflex (STNR) is an automatic movement pattern that shows up later than the other reflexes we have discussed so far. This reflex appears between 6 to 9 months old. There are two patterns for for STNR.

One movement pattern of the STNR is prompted with the head moves back (looking up). When this happens, the arms straighten and the legs bend.

This helps the baby get into the hands and knees position and is very needed in preparation for crawling. This pattern is demonstrated by the pose here on the left.

Photo by William Fortunato on Pexels

The other movement pattern of STNR is when the baby’s head moves forward (looking down). This prompts the arms to bend and the legs to straighten.

This helps the baby learn to use the two halves of the body independently of each other (top and bottom). This pose is demonstrated by the pose here on the right.

Photo by Meruyert Gonullu on Pexels

The STNR shows up as the Asymmetrical Tonic Neck Reflex (ATNR) goes away. Its purpose is to help get the baby into hands and knees position in preparation for crawling and to help the baby designate between its top and bottom half. It commonly remains in place until between 9 to 11 months old and then ‘disappears’. This is when it is considered integrated. This is typically when the child is mastering other motor tasks like preparing to take its first steps.The more advanced motor movements replace the primitive reflex.

What happens if the STNR is retained?

When the STNR is not integrated at the 9 to 11 month mark, it is retained. Someone with a retained STNR may demonstrate the following¹:

• Poor posture
• Awkward walk
• Tendency to W-sit on the floor
• Difficulty holding head in appropriate position
• Poor balance
• Difficulty with sports
• Poor space and time awareness
• Poor hand-eye coordination
• Messy eater
• Visual challenges (near to far)
• Challenges with recognizing social cues
• Memorization challenges
• Poor learning ability

How does this look in daily life? This may be the toddler who “bear walks”, has an uncoordinated crawl or scoots on their bum instead of crawling. A child with a retained STNR may even skip the crawling stage altogether! Another common theme for retained STNR is a child who prefers to lie on the floor instead sitting.

As the child gets older, a retained STNR may show up in different ways. When sitting at a desk or table they may look down, bend their arms and slouch, almost looking like they are lying on their desk. They may be very slow at copying from the blackboard. Sports may be a little harder for them too, and they may walk and move awkwardly. Sometimes these traits are what makes them appear to have sensory processing disorder.

STNR and sensory processing disorder

So how does a retained STNR relate to sensory processing disorder (SPD)? Or do they even relate at all? First, a retained STNR (or any other primitive reflex) does not mean that someone has SPD or the other way around. The connection is much looser than that. It goes back to what happens in the developing brain. 

Primitive reflexes are active while the baby is amassing a great amount of information about their world. Taking in sensory information is how that happens. They take in information from the world around them, react and respond to it and even take in sensory information from their own body from that reaction. It is a great loop of sensory and motor movements.

If sensory processing is a problem, the primitive reflex may remain active and will limit the motor skill development as well as additional sensory processing skills. Addressing the reflex will allow not only for higher motor functions but also improved sensory processing.

So what can you do to help someone with a retained STNR?

Integrating the STNR

When a reflex is retained past its useful time period there are some things that can be done to help. First off, I always recommend that you speak with your pediatrician and ask for an occupational or physical therapy referral to someone who specializes in primitive reflexes. They will be able to assess for retained reflexes and provide a plan to help these get integrated. 

A professional in primitive reflexes is useful because when one reflex is retained, often others remain as well. Helping these reflexes integrate helps the brain and body function more optimally.

The activities that you do to help integrate the Symmetrical Tonic Neck Reflex often imitate parts of the reflex itself, but should not stimulate the actual reflex. A very easy way to work on the STNR is to do the cat/cow yoga pose. You start on hands and knees and arch the back as high as possible while tucking the chin and looking between the knees. Take a breath and then look up at the ceiling and collapse or sway your back down towards the floor. Repeat, going slow with the breath cycle.

Another, very simple way to integrate the STNR is to do a lot of crawling, preferably in the alternate hand/leg pattern. You can make this more fun for older kids by hiding puzzle pieces around the room to retrieve, making a crawling obstacle course, or having them push a ball with their head while crawling across the room.

Doing activities like these every day to integrate the STNR can usually help integrate it in 4-6 weeks. Totally worth 5 minutes a day! You will likely be making really great changes for the Symmetrical Tonic Neck Reflex and their sensory processing at the same time.