Hypotonia

Hypotonia is a state of low muscle tone, often involving reduced muscle strength. It is not itself a specific medical disorder but a potential manifestation of many different diseases and disorders that affect motor nerve control by the brain or muscle strength. Hypotonia is a lack of resistance to passive movement, distinguishing it from muscle weakness, which instead impairs active movement; central hypotonia originates in the central nervous system, while peripheral hypotonia arises from problems in the spinal cord, peripheral nerves, or skeletal muscles. Severe hypotonia in infancy is commonly known as floppy baby syndrome, and while recognizing the sign is usually straightforward, diagnosing its underlying cause is often difficult.