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.