[Developmental change of Moro reflex studied with a three-dimensional motion analysis system]

We evaluated developmental change of the reaction time of the Moro reflex from birth to three months of age using a three-dimensional motion analysis system (ToMoCo-VM:Tousou system). The reaction time was the shortest in one-month-old babies and became successively prolonged in two and three-month-old babies, showing a U-shaped pattern. The three phase of the Moro reflex, as defined by McGraw, changed with advancing age. The reaction time changed monthly. At the same monthly age, the reaction time was the same irrespective of the phase.