muscle tone
The continuous partial contraction of muscles at rest, providing postural stability and readiness for movement.
Full Definition
Muscle tone refers to the continuous, passive partial contraction of muscles that provides postural support and maintains readiness for voluntary movement. Normal muscle tone (normotonia) allows for smooth, coordinated movement and appropriate postural responses. Abnormal muscle tone can manifest as hypertonia (increased tone) seen in conditions like spasticity or rigidity, or hypotonia (decreased tone) resulting in floppy or low muscle tone. Changes in muscle tone significantly impact functional performance and are common sequelae of neurological conditions such as stroke, traumatic brain injury, cerebral palsy, or neuromuscular diseases. Occupational therapists assess muscle tone through clinical observation and handling techniques, and treatment may include positioning, therapeutic handling, splinting, or neuromuscular facilitation techniques to optimize tone for functional activities.
Usage
Usage note: Distinguish from muscle strength (force production capability) and spasticity (velocity-dependent increase in tone).
In Context
- "The client presents with increased muscle tone in the left upper extremity following the cerebrovascular accident." — Clinical assessment note
- "Therapeutic positioning was used to inhibit abnormal muscle tone and facilitate more normalized movement patterns." — Treatment intervention note