hypertonia
Pronunciation: HY-per-TOH-nee-uh
Abnormally increased muscle tone or resistance to passive movement, encompassing both spasticity and rigidity.
Full Definition
Hypertonia is the clinical term for excessive muscle stiffness or resistance to passive limb movement and is a common finding in rehabilitation patients with upper motor neurone lesions. It is an umbrella term that includes spasticity (velocity-dependent, associated with pyramidal tract damage) and rigidity (velocity-independent, associated with extrapyramidal lesions). Editors must not use 'hypertonia' and 'spasticity' interchangeably; spasticity is a subset of hypertonia. The antonym is 'hypotonia'. Documentation should specify the nature of hypertonia where possible. The adjective form is 'hypertonic'.
Usage
Usage note: Do not use as a synonym for 'spasticity'. Spasticity is velocity-dependent hypertonia; rigidity is velocity-independent hypertonia. Both fall under the hypertonia umbrella.
In Context
- "Hypertonia affecting the bilateral lower limbs was identified as the primary barrier to independent transfer." — Rehabilitation assessment report
- "The distinction between spasticity and rigidity within the patient's hypertonia required further neurological evaluation." — Specialist consultation letter