Abstract
In proposals for the legal obligation for riders of motorised two-wheelers to wear helmets, requirements will be included for the construction of the helmet relating to protection against injuries in accidents, without the risk of causing other serious injuries. In order to make the helmet acceptable as a means of protection, it must be made attractive, or at least tolerable, from other points of view. The definition of standards for helmets should be based on a number of functional requirements. Possible first and second order functional requirements are considered.