Which increased tone remains the same throughout ROM and is not velocity dependent, commonly seen in basal ganglia disorders such as Parkinson's disease?

• A. Spasticity
• B. Rigidity
• C. Tremor
• D. Hypertonia

Answer: (B)

Rigidity is an increased muscle tone that stays the same through the entire range of passive movement and is not affected by how fast you move the limb. In Parkinson’s and other basal ganglia disorders, this velocity-insensitive resistance—often described as lead-pipe rigidity—fits the description in the question. Spasticity, by contrast, increases with faster movement and reflects upper motor neuron pathology. Tremor is an involuntary rhythmic movement, not a sustained change in tone. Hypertonia is a broad term for increased tone, but rigidity is the specific pattern most characteristic of PD.