Motor functions: associated primitive reflex profiles.

The results of reflex/motor activity interactions in 177 normal infants are evaluated. The asymmetrical tonic neck reflex, tonic labyrinthine reflex-supine, and Moro reflexes were assessed for each child at birth and at intervals up to 12 months. Ages of rolling prone to supine, rolling supine to prone, and sitting alone were elicited from parents. The effects of the primitive reflexes on early motor activity were assessed, and statistically significant correlations were demonstrated between decreased reflex activity and the emergence of motor milestones. The distinctive association of reflex activity with motor function suggests the interaction of several reflexes (a primitive reflex profile) rather than the influence of isolated reflex activity. Such patterns support the hypothesis that decreasing primitive reflex activity is associated with the onset of volitional motor activity in normal infants.