A state of excessive or inadequate muscle tone. The term was coined by the neurologist Hermann Oppenheim (1858-1919) in 1911 to indicate that “muscle tone was hypotonic at one occasion and in tonic muscle spasm at another, usually, but exclusively, elicited upon volitional movements”, a definition that is still used. A transient form of dystonia is quite common in preterm infants, with the incidence ranging from 40% to 80%. It manifests itself as either as hypotonia, or more typically as increased muscle tone with extensor hypertonus through the trunk and lower extremities and increased flexor bonus through the upper extremities.
See Axial muscles, Cerebral palsy, Dyskinesia, Hypotonia, Muscle tone (or power), Parkinson’s disease, Preterm infants, Transient dystonia