"Neurotrauma" . "German inventions" . "Injuries of head" . "Sustainable transport" . "Bicycle helmets" . "Cycling safety" . "Cycling equipment" . "Protective gear" . "Childhood" . "19th-century inventions" . "Appropriate technology" . "Pediatrics" . "Cycle types" . "Cycling clothing" . "Motor vehicles" . "Bicycles" . "Sustainable technologies" .