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The asymmetrical tonic neck reflex in normal first and third grade children
Insights
The asymmetrical tonic neck reflex (ATNR) may still be present in normal children up to third grade, especially with left head rotation. Visible muscle tone changes or elbow flexion are considered normal findings in this age group.
Area of Science:
- Developmental Pediatrics
- Neuroscience
- Motor Control
Background:
- Diminished inhibition of the asymmetrical tonic neck reflex (ATNR) is a key indicator in assessing children with developmental delays.
- Limited data exists on the typical integration patterns of primitive reflexes like ATNR in healthy children across different ages.
Purpose of the Study:
- To investigate the prevalence and characteristics of ATNR integration in normal first and third-grade children.
- To establish normative data for ATNR responses in a typically developing pediatric population.
Main Methods:
- 44 first graders and 36 third graders participated in the study.
- Children were assessed in a quadrupedal position, with active and passive head rotation to the left and right.
- Observed responses included changes in muscle tone and elbow flexion in the ipsilateral arm.
Main Results:
- All children exhibited varying degrees of ATNR responses, including elbow flexion and muscle tone changes.
- First-grade children showed significantly more ATNR evidence compared to third graders, particularly with leftward head rotation.
- Frequent muscle tone changes or up to 30% elbow flexion in the ipsilateral arm were observed as normal.
Conclusions:
- The persistence of ATNR, indicated by muscle tone changes or elbow flexion, is considered normal in children up to the third grade.
- These findings provide valuable reference points for clinicians evaluating developmental milestones and primitive reflex integration.
Abstract:
Diminished inhibition of the asymmetrical tonic neck reflux (ATNR) is frequently used as a clinical tool when evaluating children with maturational lags, sensory integration deficits, and learning and behavioral dysfunction. However, limited observations are available on the degree of integration of this primitive reflex in normal children at different age levels. In this study, 44 first grade and 36 third grade normal children were tested in the quadrupedal position by right and left lateral rotation of the head both actively and passively. Varying degrees of elbow flexion or muscle tone changes were elicited in all. First grade children displayed significantly more evidence of this reflex, especially when the head was rotated to the left. The results of this study indicate that frequent, visible muscle tone changes or elbow flexion to 30% in the arm ipsilateral to the skull position could be considered normal in children through the third grade.