STNR (Symmetrical Tonic Neck Reflex)

STNR (Symmetrical Tonic Neck Reflex)?

The STNR is a primitive reflex that develops in infants between 6 to 9 months of age and plays a critical role in early motor development, especially crawling.

• It's often referred to as the "crawling reflex".

• It helps the baby separate movements of the upper and lower body.

• The reflex presents a two-part pattern:

  • When the head is lifted: arms straighten, legs bend.

  • When the head is lowered: arms bend, legs straighten.

It allows a child to move from lying on the floor to getting on hands and knees—an essential step for crawling. 

When Should STNR Fade Away (Integrate)?

• The STNR should be fully integrated by 9 to 11 months of age.

• It is a transitional reflex, meant to disappear as the brain matures and voluntary motor control takes over.

• Integration supports:

  • Postural control

  • Bilateral coordination

  • Eye-hand coordination

The further development of other reflexes, such as the Tonic Labyrinthine Reflex (TLR)

What happens if it doesn't integrate?

• Motor & Postural Issues: Skipped crawling, poor posture (W-sitting, slouching), weak muscle tone, difficulty sitting still, or frequent falls from chairs.

• Visual & Reading Challenges: Trouble with visual tracking, copying from the board, or poor depth perception.

• Writing & Fine Motor Difficulties: Sloppy handwriting, poor pencil grip, or trouble organizing thoughts on paper.

• Math & Spatial Reasoning Delays: Difficulty with vertical tracking (for columns) or judging distances.

• Coordination & Sports Struggles: Challenges with ball games, swimming, or overall body awareness.

• Classroom Behavior & Learning: Appearing inattentive, fidgety, easily fatigued, or even exhibiting symptoms similar to ADHD.