The plantar response in normal newborn infants

The neonatal plantar response has been reported as extensor in 90% of newborns and flexor in 93% of newborns, leading to uncertainty about its reliability and significance. To determine the normal neonatal plantar response we examined 349 healthy newborn infants, > 32 weeks gestation within 24 hours of birth. A supramaximal noxious stimulus was applied in a standardized manner to the lateral plantar surface of each foot. The plantar response was extensor in 90%, equivocal in 7%, and flexor in 3%. With proper physiologic technique, the normal neonatal plantar response is extensor.