A cerebellar dysfunction would most affect which movement task?

• A. Finger-to-nose coordination
• B. Leg extension strength
• C. Gait speed
• D. Vestibular reflexes

Answer: (A)

The cerebellum fine-tunes movement, ensuring accuracy and smooth timing by comparing the intended trajectory with what’s actually produced and making real-time corrections. A hallmark of cerebellar dysfunction is dysmetria—overshooting or undershooting a target—and an intention tremor that worsens as you approach the target. Finger-to-nose requires precise, coordinated, multi-joint control and accurate trajectory planning, so cerebellar problems disproportionately degrade this task.

Leg extension strength relies more on muscle force and corticospinal control than on precise coordination, so cerebellar issues don’t primarily reduce strength. Gait speed can be influenced by many factors and cerebellar disease often produces ataxic gait, but the fundamental deficit you’d expect most clearly is impaired coordination seen with finger-to-nose. Vestibular reflexes involve the vestibular system and brainstem, with the cerebellum helping modulate them, but the direct, targeted coordination task remains the strongest indicator of cerebellar involvement.