cogwheel phenomenon
cogwheel rigidity

The most common manifestations include: bradykinesia, cogwheel rigidity and a lack of balance.

The combination of tremor and increased tone is considered to be at the origin of cogwheel rigidity.

When limbs of the person with PD are passively moved by others a "cogwheel rigidity" is commonly seen.

In parkinsonism the rigidity can be uniform (lead-pipe rigidity) or ratchety (cogwheel rigidity).

Pseudoparkinsonism: drug-induced parkinsonism (cogwheel rigidity, bradykinesia/akinesia, resting tremor, and postural instability; more frequent in adults and the elderly).

These symptoms may include a tight or mask-like expression on the face, drooling, tremors, pill-rolling motions in the hands, cogwheel rigidity (abnormal rigidity in muscles characterized by jerky movements when the muscle is passively stretched), and a shuffling gait.