What is spasticity?

• A. A condition characterized by muscle stiffness and involuntary contractions, often associated with neurological injury.
• B. A condition characterized by muscle weakness only.
• C. A temporary fatigue of muscles after exercise.
• D. Normal muscle tone.

Answer: (A)

Spasticity is a velocity-dependent increase in muscle tone with involuntary contractions that follows injury to the upper motor neurons. This means that when you move or stretch the muscle quickly, it resists more than normal and may jerk or spasms occur. The combination of stiffness and these involuntary contractions is the hallmark, and it commonly appears after neurological injuries such as stroke, spinal cord injury, or brain injury.

This best answer contrasts with the other descriptions: purely weakness refers to reduced strength without the abnormal high tone or reflex activity; temporary fatigue after exercise describes a short-lived tiredness rather than sustained increased tone and spasms; and normal muscle tone means there is no abnormal resistance or involuntary activity.