Spasticity
Pronunciation: spas-TIS-ih-tee
A velocity-dependent increase in muscle tone resulting from an upper motor neuron lesion, manifesting as resistance to passive movement; a key clinical parameter in rehab technology prescription.
Full Definition
Spasticity is a motor disorder characterised by a tonic stretch reflex (muscle tone) that is abnormally increased proportionally to the speed of passive limb movement, arising from damage to corticospinal pathways (upper motor neuron syndrome). In rehab technology documentation, spasticity influences device selection significantly: high spasticity may contraindicate certain orthotics, require specific seating configurations, or necessitate anti-spasticity positioning devices. It is commonly rated using the Modified Ashworth Scale (MAS) or Tardieu Scale, and editors should ensure the scale used is named clearly. Spasticity must not be conflated with rigidity (which is velocity-independent) or contracture (a fixed structural shortening).
Usage
Usage note: Do not use 'spasticity' and 'rigidity' interchangeably. Both describe increased tone but have distinct mechanisms, clinical appearances, and technology implications.
In Context
- "Lower-limb spasticity rated 3 on the Modified Ashworth Scale was a contraindication for the rigid-ankle AFO initially prescribed." — Orthotic evaluation report
- "The editor corrected 'rigidity' to 'spasticity' after cross-referencing the neurological diagnosis of spinal cord injury in the chart." — Peer-review annotation