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.