Tone

Test tone


Flaccid tone is the hallmark of a lower motor neuron lesion, but can occur rarely in UMN lesions.
To look for altered tone, and particularly spasticity
  • in the arms rapidly pronate, supinate, flex and extend the arms at the elbow
  • roll the legs from side to side, watching movement of the foot
  • rapidly flex and extend the legs at the knee,
  • sharply dorsiflex the ankle with knee bent to evoke clonus.
If Parkinson's disease is suspected, from history of stiffness and loss of hand dexterity, tremor, lack of arm swing, gait, posture, and bradykinesia; slowly flex and extend the fingers, wrists and slowly pronate and supinate the elbow, looking for plastic or cogwhell rigidity. This is less easily appreciated with rapid vigorous movements needed to demonstrate spasticity.