Brief clinical and laboratory observations.
D000293:Adolescent; D001294:Attitude to Health; D003299:Cooperative Behavior; D005260:Female; D006260:Head Protective Devices; D006801:Humans; D008297:Male; D011482:Protective Devices; D000297:Psychology, Adolescent; D012309:Risk-Taking; D012622:Seat Belts; D011795:Surveys and Questionnaires