The protective effects of helmets in skiers and snowboardersBMJ 2011; 342 doi: http://dx.doi.org/10.1136/bmj.d857 (Published 10 February 2011) Cite this as: BMJ 2011;342:d857
- Gerhard Ruedl, postdoctoral researcher,
- Martin Kopp, professor,
- Martin Burtscher, professor
In the winter of 2008-9, public awareness of the benefits of wearing ski helmets heightened after two celebrities were involved in fatal skiing injuries in Europe and North America.1 2 3 In Austria, a German politician and a mother of four children collided on a ski slope on New Year’s Day 2009. The politician, who was wearing a ski helmet, survived with a traumatic brain injury, whereas the woman, who was not wearing a helmet, died. In Canada, actress Natasha Richardson died after a traumatic head injury sustained while skiing without a helmet on a beginner slope in Quebec in March 2009⇓.
During the weeks after the death of Natasha Richardson, visits to the emergency room at the Montreal Children’s Hospital increased by 60%.1 It was concluded that the media coverage had caused anxiety among parents, prompting those who might not otherwise have sought medical care to bring their children to the emergency room.1In addition, 15% of neurosurgeons in Germany, Switzerland, and Austria bought a helmet after the fatal collision of the German politician, possibly as a result of the increased media coverage.2 The use of helmets increased in Austria from 44% in December 2008 to 57% in April 2009 in skiers and snowboarders, and it has become obligatory for children under 16 years in most Austrian provinces since the winter season 2009-10.3 However, prospective studies evaluating the effects of this extended helmet use are still lacking.
What are the advantages of wearing a ski helmet? Head injuries account for 9-19% of all injuries reported by ski patrols and emergency departments.3 4 Severe head injuries include traumatic brain injury, which is a leading cause of death among winter sports participants.4 A recent meta-analysis showed that skiers and snowboarders with a helmet were significantly less likely than those without a helmet to have a head injury (odds ratio 0.65, 95% confidence interval 0.55 to 0.79). In children under 13 years the odds ratio was 0.41 (0.27 to 0.59).4 A subsequent study found a similar effect across all age groups.3 It has been suggested that head-neck-helmet biomechanics may increase the risk of cervical spine injury when wearing a helmet, especially in children, who have a greater head to body weight ratio.4 5 However, recent studies have not confirmed this notion.4 5 Thus, wearing a ski helmet seems to make sense to prevent head injuries in all age groups.
Does wearing a ski helmet have disadvantages? According to the risk-compensation hypothesis, wearing a helmet may provide a false sense of security, resulting in riskier behaviour on the slopes.6 7 However, one study of self reported behaviour found that although skiers and snowboarders who were risk takers skied faster than cautious people (53 v 45 km/h), the use of helmets was nearly equal in both groups (59.2% v 59.7%).7 In addition, significantly more skilled skiers wore helmets (76.9% v 59.0%), and a similar proportion of those who did and did not wear helmets exhibited risk taking behaviour (29.8% v 30.2%).7 Other studies have also shown that helmet use is higher in more skilled skiers than in less skilled ones.6 So the use of a helmet is not necessarily associated with a higher level of risk taking but primarily with a higher level of skill.
Other arguments against helmets are that they impair hearing and limit the field of vision.6 8 Only a few studies have assessed these aspects. A recent study showed that ski helmets could raise the hearing threshold of frequencies between 2 kHz and 8 kHz, which are characteristic of the hissing caused by a skier or snowboarder passing closely by or breaking behind.8 However, sound was not attenuated at the frequencies characteristic of the human voice (<1 kHz), so that warning shouts should be heard.8 In addition, the rules of the International Ski Federation (FIS) call for skiers to use their sight to avoid collisions. Collisions often lead to multiple trauma and are likely to involve the head. The victims of collisions are injured more often and more severely than those who cause the collision (93% v 25%), because the victim is usually hit unexpectedly and does not have time to react properly.9
One study found that most head injuries (74%) occurred when skiers hit their head on the snow,10 10% when they collided with other skiers, and 13% when they collided with fixed objects. These results suggest that protecting the head with a helmet must be beneficial.
In terms of the effect of helmets on field of vision, a randomised controlled pilot study found no differences in mean reaction time between people wearing a ski helmet or ski cap.11 Ski goggles increased the reaction time, however, so may limit the field of vision.11
Evidence shows that ski helmets protect against head injury. Education about brain trauma can have a positive effect on attitudes towards wearing a helmet.2 In addition to education and increased public awareness, helmet use could be increased and the incidence and severity of brain injuries decreased by the introduction of helmet loan schemes or routine inclusion of helmets in rental packages.12 Future studies should evaluate strategies that focus on individual skiing behaviour. One example of such a study would be a randomised trial that compares the preventive effects of different educational (for example, web based) and behaviour change models. Public health physicians should take a leading role in research and in implementing measures for injury prevention.
Cite this as: BMJ 2011;342:d857
Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Provenance and peer review: Not commissioned; externally peer reviewed.