Mass. Gen. Laws ch. 85 § 11B 1/2
Any person 16 years of age or younger operating in line skates, a skate board, a scooter or other manually-propelled wheeled vehicle or riding as a passenger on any such manually-propelled vehicle on a public way, bicycle path or on any other public right-of-way shall wear a helmet. Such helmet shall fit the person's head and be secured by straps at all times while operating in line skates, scooters, skate board or other manually-propelled wheeled vehicle and shall meet the standards for helmets established by the American National Standards Institute (ANSI Z 90.4) or subsequent standards or the Snell Memorial Foundation's 1984 standard for use in bicycling or subsequent standards. A violation of this section shall not be used as evidence of contributory negligence in a civil action.
Mass. Gen. Laws ch. 85, § 11B 1/2