Cycling accidents are not significantly more productive of head injuries than the generality of child accidents. Child cyclists accidents account for 1.2% of all head injury admissions, and less than 0.3% of all admissions (approximately half of all children have bicycles). Child cyclist head injury rates are already falling at a rate which cannot be accounted for by helmet use (for example, they are falling in road crashes where TRL counts indicate helmet use is, if anything, falling).
The figures for child admissions to hospitals, as provided by the Department of Health, offer little if any support for the idea of effectiveness of bicycle helmets for children at the population level (this does not necessarily mean that helmets do not provide any benefit in the event of an accident, it could be that there is benefit but it is eroded by balancing behaviour on the part of cyclists).
We are told that offroad play accounts for nine tenths of child cycle use. If this is true the figures indicate that offroad play is an less risky than road riding, by approximately an order of magnitude. If anything this will actually be an understatement, since the youngest children rarely if ever ride on the roads. The figures do show that being a passenger in a motor vehicle which is about half as likely to result in a head injury, without adjustment for exposure, as cycling on the roads - this highlights the immense disparity in risk experienced by those inside and outside motor vehicles, and further underlines the need to approach child injuries by reduction of risk at source rather than exploring palliative measures. Most risk management starts from the premise that risk should be reduced at source before personal protective equipment is considered.
The figures offer no support for the idea of helmet compulsion. On the contrary, they show that the "problem" of child cyclist head injuries is both small and getting smaller; they show that cycling is not uniquely productive of head injuries; they show that helmet use by pedestrians would save significantly more injuries; they show that of all sources of head injury the most significant by far is trips and falls, which consistently account for around half of all child head injury admissions.
These figures also show that a number of recent claims made in support of helmet compulsion are bogus, notably the idea of 20,000 or 28,000 head injuries per annum. They show that the proportion of serious injuries to fatalities is consistent with figures reported by the DfT of around 30:1, and that serious injuries follow the pattern of all injuries in that around half do not involve the head. They show that in a generous estimate helmets might be expected to have a mitigating effect in around two thirds of serious head injuries, and that the reality may well be less than this. This casts doubt on some research which claims that substantially more than two thirds of head injuries might be prevented by helmets.