Neonatal hypotonia

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Hypotonia, or low muscle tone, is usually detected at birth or during infancy.

The first part of the figure shows observational findings detected in infants with primary hypotonia, including frog-leg positioning owing to low tone and paucity of movement, the presence of a nasogastric feeding tube owing to poor feeding, tracheostomy for respiratory failure, knee dimpling from restricted movements in utero, and ptosis with myopathic facies in neuromuscular junction disorders.

Physical examination maneuvers including horizontal suspension, lift to sitting position, and ankle flexion demonstrate differences between typical infants and infants with hypotonia.