hypotonia
Pronunciation: HY-poh-TOH-nee-uh
Abnormally decreased muscle tone, presenting as reduced resistance to passive movement and often associated with lower motor neurone lesions or cerebellar dysfunction.
Full Definition
Hypotonia, also termed flaccidity in some clinical contexts, describes a reduction in the normal resting tension of muscle and the decreased resistance felt when a limb is moved passively. It is commonly encountered in rehabilitation following lower motor neurone lesions, peripheral neuropathies, cerebellar injuries, or in infants with developmental neurological conditions. Editors should note that 'hypotonia' and 'flaccidity' are not always interchangeable: flaccidity typically implies complete loss of tone, whereas hypotonia encompasses a spectrum. The adjective form is 'hypotonic'. The opposite of hypertonia, it must not be confused with 'weakness' (reduced active force generation).
Usage
Usage note: Distinguish from 'weakness' (reduced active force). Hypotonia is a tone descriptor, not a strength descriptor. Specify severity and distribution in clinical documentation.
In Context
- "Hypotonia in the left upper limb was consistent with the peripheral nerve injury sustained in the industrial accident." — Inpatient rehabilitation admission note
- "Pediatric rehabilitation goals were adjusted to address the infant's generalised hypotonia affecting postural control." — Pediatric rehabilitation care plan