Helmet Effectiveness Research

Ski helmets are increasingly the subject of controversy between safety and personal choice.  The purpose of this article is to identify research and statistics that argue the effectiveness and safety of helmets.  Please help contribute to the article by adding in links and citations to sources.   The choice is yours, this article focuses on available research. 

Deaths and Helmets

Accurate data on traumatic deaths on the slopes is not easy to come by for many of the main ski countries in the world. The most complete publicly available data that I am aware of on deaths on the slopes comes from the USA. On average over the last ten years, there have been about 39 deaths per year from snow sports (Source, NSAA March 2009). There is some year on year variation - for example, during the 2006/07 season there were 22 deaths from 55.1 million skier/snowboarder days. This gives a death rate that year of one for every 2.5 million skier days. (Source - NSAA). This compares to 37 skier and snowboarder deaths in the U.S. in 2002/03. With 57.6 million visits in 2002/2003, the death rate that year equates to one death every 1.6 million skier visits.

In a published research study of the death rates from skiing and snowboarding in US resorts from 1991/2 to 1998/9 Shealy, Ettlinger and Johnson reported 285 deaths from a total of 426.2 million participant visits (MPVs). This equates to an overall rate of 0.67 deaths per MPVs - put another way, statistically a death can be expected for every 1.49 million visits to a ski area. Interestingly, the death rate for snowboarding (0.46 per MPV) was 34% lower than that for alpine skiing (0.70 per MPV). The causes of death and the fatality rate associated with them are given in the table below (adapted from Shealy et al) :-Modality of death Fatality rate per PMV Ratio of skiing to snowboarding death rates
Snowboarding Skiing
Overall 0.455 0.702 1.54 to1
Impact -object or person 0.195 0.563 2.89 to 1
NARSID* 0.081 0.016 0.19 to 1
Impact with snow 0.081 0.085 1.05 to 1
Jump 0.065 0.022 0.34 to 1
Other 0.033 0.016 0.48 to 1

(* NARSID = Non-Avalanche Related Snow Immersion Death - see my summary page for more details)

So the leading mechanism of death in both sports is a collision with either a static object (tree, for example) or another person. This is particularly so for skiers. This aside, snowboarders are most likely to die from a NARSID or as the result of a jump.

In the 1998/99 part of the study, Shealy and colleagues followed the deaths as they happened and found that, where the information was available, 35% of individuals who died were wearing a helmet. This is much higher than the rate of helmet use amongst the general population on the piste. Two of the deaths amongst snowboarders resulted from them being struck by young skiers wearing helmets who had jumped without being able to see where they would land.

Shealy et al conclude "...the findings are not particularly supportive of the notion that wearing helmets will significantly reduce the number of fatalities in winter snow sports". This was supported by a presentation at the last ISSS meeting by the Chief Medical Examiner for the state of Vermont, USA - Dr Paul L. Morrow. Dr Morrow was of the opinion that of 54 deaths at commercial ski areas in Vermont from 1979/80 to 1997/98, helmets would not have been of any particular value in saving any of the lives lost - as the degree of trauma simply overwhelmed any benefits that the helmet might convey in an impact. To quote Shealy et al again - a team of highly respected ski injury researchers - "On the basis of results to date, there is no clear evidence that helmets have been shown to be an effective means of reducing fatalities in alpine sports".

Its a sobering fact for example that more than half of the people involved in fatal accidents in 2008/09 at ski areas in the USA were wearing helmets at the time of the incident (Source - NSAA). As Shealy states "Even though the prevalence of helmet utilization is rising by 4 to 5 percent per year in the U.S., there has been no statistically significant observable effect on the incident of fatality."

In another recent scientific publication, Shealy and his colleagues found that the most common primary injury in ski and snowboarding fatalities is some sort of head injury – approximately 60 percent of ski fatalities involve a head injury. However, it is critical to place this into its proper context. “While some sort of head injury is usually the first listed cause of death, most of the fatalities also involve multiple, or secondary trauma sites; single causes of death are not common.” Most fatalities appear to occur under circumstances that are likely to exceed the protective capacity of current helmets designed for recreational snow sports. (Source - “Do Helmets Reduce Fatalities or merely Alter the Patterns of Death?” Shealy, J., Johnson, R., and Ettlinger, C., 2008)

Skiing Helmets An Evaluation of the Potential to Reduce Head Injury

CPSC, January 1999 Article download link (PDF)

As part of an overall strategy to reduce head injuries, the U.S. Consumer Product Safety Commission (CPSC) staff conducted an evaluation of head injuries associated with snow skiing and snowboarding. The purpose of this activity was to assess the potential for helmets to reduce the risk of head injury.  From 1993 to 1997, the estimated number of hospital emergency room-treated injuries associated with skiing declined from 114,400 to 84,200. Head injuries associated with skiing were essentially unchanged. However, the estimated 12,700 head injuries in 1997 represent a larger proportion of total injuries than did the estimated 13,600 head injuries in 1993. During the same time period, snowboarding injuries nearly tripled from 12,600 to 37,600. The estimated number of head injuries associated with snowboarding increased from 1,000 in 1993 to 5,200 in 1997. Overall, head injuries represent about 14 percent of all skiing and snowboarding injuries. Among children under 15 years of age, head injuries are about 22 percent of the total estimated injuries (or an estimated 4,950 head injuries annually).

From February 1 through March 31, 1998, CPSC conducted a special investigation study of skiing- and snowboarding-related head and neck injuries. A key aspect of this study was to obtain information regarding the point of impact on the head to determine whether a helmet would have covered the area of injury and, therefore, might have prevented or reduced the severity of the injury. The study indicated that 44 percent of head injuries -- or an estimated 7,700 injuries annually -- could be addressed by helmet use. The study also showed that for children under 15 years of age, 53 percent of head injuries (approximately 2,600 of the 4,950 head injuries annually) are addressable by use of a helmet. In addition, based upon a review of skiing- and snowboarding related death certificates, 11 deaths per year solely attributed to head injuries might be prevented by the use of helmets.

(Contributed by Marcus Brody link)

Testing the risk compensation hypothesis for safety helmets in alpine skiing and snowboarding.

Scott MD, Buller DB, Andersen PA, Walkosz BJ, Voeks JH, Dignan MB, Cutter GR.

California State University, Communication Arts and Sciences, Chico, California, USA.

From: http://www.ncbi.nlm.nih.gov/pubmed/17567972

(Contributed by Marcus Brody link)

The effect of helmet use on injury severity and crash circumstances in skiers and snowboarders

Brent Hagel^a,b,,, I. Barry Pless^c, Claude Goulet^d, Robert Platt^c and Yvonne Robitaille^e

From: Here (though I'm not sure this is a static link)