The plantar response in normal newborn infants

Area of Science:

• Neonatal Neurology
• Developmental Pediatrics
• Neurodevelopmental Assessment

Background:

• Conflicting reports exist regarding the neonatal plantar response, with some suggesting extensor in 90% and others flexor in 93% of newborns.
• This ambiguity creates uncertainty about the reliability and clinical significance of the plantar response in neonates.
• A standardized, reliable assessment of the neonatal plantar response is crucial for early neurological evaluation.

Purpose of the Study:

• To establish the normal neonatal plantar response in healthy newborn infants.
• To resolve discrepancies in existing literature regarding the plantar response in neonates.
• To provide a definitive understanding of the typical plantar response for accurate clinical interpretation.

Main Methods:

• Examined 349 healthy infants with gestational age > 32 weeks within 24 hours of birth.
• Applied a supramaximal noxious stimulus to the lateral plantar surface of each foot in a standardized manner.
• Documented the resulting plantar response (e.g., extensor, flexor, equivocal).

Main Results:

• The neonatal plantar response was extensor in 90% of infants.
• An equivocal response was observed in 7% of infants.
• A flexor response was noted in only 3% of infants.

Conclusions:

• With the application of proper physiologic technique, the normal neonatal plantar response is extensor.
• This finding clarifies previous uncertainties and establishes a reliable baseline for neonatal neurological assessment.
• The extensor plantar response is the expected finding in healthy neonates, aiding in the identification of neurological abnormalities.