There is a lot to consider, 400+ reports I think the figure is
helmets or helmet laws - a choice or both
helmets - trying to weigh up the pro and cons - limited interest - some basics helpful,
design, fit, impacts, risk level, helmets could protect but increase impacts or accidents,
Clarke CF, Health and safety assessment of state bicycle helmet laws in the USA, http://www.ctcyorkshirehumber.org.uk/US ... t_laws.pdf
choice people make in head gear when walking, hats, caps, beanies, bare headed, what makes them choose - temp, sun, religious connections, conventions, message/image, safety, show, changes people make eg helmet on a bike but not in a car,
helmet laws - discouaging effect,
eg NZ 2.3km Fig 7, before legislation, 1.15km in 2003/04.
eg In Victoria, Australia, helmet use increased from approximately 32% to 65% Robinson 1996. However, cycling reduced by approximately 36%. In effect helmet use increased from 32% of 100 to 65% of 64, or from 32 to 42, an extra 10 wearing from 68 not wearing prior to the law. In comparison to the extra 10 wearing helmets, 36 fewer were cycling and 22 choose not to wear them, in spite of the legal requirement.
Eg, New South Wales the largest of the Australian states. In 1991 the surveys counted 6072 child cyclists, by 1992, 3857 and by 1993, 3414. By 1993 an extra 569 were helmeted compared with a drop of 2658.
Video exploring why people make their choice and why helmet laws discourage cycling, benefits of cycling. Risk of head injury v benefits of cycling