Hypotonia is often a sign of abnormality in the case of a newborn or older infant, and may suggest the presence of central nervous system dysfunction, genetic disorders, or muscle disorders. Hypotonic infants rest with their elbows and knees loosely extended, while infants with normal tone tend to have flexed elbows and knees. Head control may be poor or absent in the floppy infant with the head falling to the side, backward or forward.
Review Date 4/24/2023
Updated by: Anna C. Edens Hurst, MD, MS, Associate Professor in Medical Genetics, The University of Alabama at Birmingham, Birmingham, AL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.