Related Clues:

• Involuntary muscle contraction
• Muscle cramp
• Big jerk
• Square on many board games
• Set in
• Sudden jerk
• Throe
• Writer's cramp, for example
• Ignite
• Flurry of activity
• Muscle woe
• Seizure
• Fax machine button
• Turn on
• Involuntary contraction