Which statement about rigidity is true?

• A. It is velocity dependent
• B. It is not velocity dependent
• C. It occurs with peripheral neuropathy
• D. It is only in tremor

Answer: (B)

Rigidity in Parkinsonism is a constant, velocity-insensitive increase in muscle tone, described as lead-pipe rigidity. That means when you passively move a limb, the resistance stays the same regardless of how quickly you move it. This contrasts with spasticity from upper motor neuron lesions, where resistance grows with faster movement (velocity-dependent). Peripheral neuropathy doesn’t produce this uniform rigidity pattern; it typically causes weakness or sensory changes rather than a constant, speed-independent resistance. Rigidity can be present with tremor (cogwheel rigidity) but it isn’t limited to tremor and can occur without tremor as well. So the true statement is that rigidity is not velocity dependent.