Motor: Exam Demonstration

Upper extremity tone and strength

Testing the tone of muscles is illustrated first. With an upper motor neuron lesion, one would notice marked spasticity and resistance to passive movement of the limbs. In Parkinson disease, cogwheel rigidity is often present in the extremities.

Strength in selected muscles is tested to determine the integrity of the motor systems (corticospinal tract/UMN and lower motor neurons/LMN). With an UMN lesion, there is weakness, especially in the extensors of the upper extremities, but no signs of atrophy or fasciculations, which are characteristic of LMN lesions.  Strength is graded on a scale of 1-5, with 5 being normal strength.  Both proximal and distal muscles are tested for weakness.

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