Abstract
To the Editor:
There is an increasing body of literature and awareness of trauma-associated mortality incurred by avalanche victims. 1 –3 A significant proportion of trauma-related mortality is attributed to head and cervical injuries. The intuitive response has been to emphasize protective strategies, including helmets.
However, recent studies suggest that the benefits of helmet use in resort skiers and snowboarders are mixed. Many report benefits, whereas others suggest the evidence is far from clear. Studies on the benefits of helmet use in backcountry skiers and snowboarders are lacking, and extrapolation from studies of similar user groups is the best information we have at this time.
Climbers and mountaineers who are exposed to rock and icefall are not included in this discussion. Climbing helmets are only standardized for falling objects on the crown, not side, front, rotational, and rear impacts. Human-powered backcountry skiers and snowboarders are the group I am discussing. It is the fastest growing segment of the ski and snowboard industry.
Several recent studies call into question the effectiveness of helmets preventing severe traumatic brain injury (TBI) among snow-sports users. Baschera et al 4 recently found no decrease in severe TBI among alpine skiers, despite major increases in helmet use. They do mention off-piste users being at increased risk of severe TBI, but they also refer to these participants as “free riders,” which is a different activity than the usual “earn your turns” participant.
Similarly, Christensen et al 5 found an increasing rate of head injury in skiers and snowboarders despite a doubling of helmet use. This is in the context of ski resort participant numbers being flat for a decade or more. An increasing rate of head injury could certainly be attributed to many factors (increased awareness, diagnostic threshold, high rates of speed with modern equipment), but the finding is concerning and worrisome nonetheless. Importantly, children 10 and younger were found to have a decreasing incidence of head injury. However, young children are not typically backcountry users venturing into avalanche terrain.
Shealy et al, 6 in 2008, contended that helmet use in skiers and snowboarders prevented minor injuries, but serious TBI incidence and fatality rate were unaffected by helmet use. However, in 2014, Shealy et al7,8 added that helmet use was now having a positive impact in decreasing the potential incidence of serious TBI, yet still had no effect on fatality rate. Mountain fatalities seem to involve high-speed accidents, and it appears that the pattern of death may shift (from head to cervical spine and trunk injuries), but the outcome is likely to be the same.6,8
Analysis of injury mechanisms brings into question the use of helmets for lowering mortality from avalanche trauma. Modern snow-sport helmet technology is made to protect users from impacts at speeds of between 11 and 14 miles/h (18–23 km/h). Avalanches (along with their victims) travel at speeds of 60 to 80 miles/h (97–129 km/h), and take about 5 seconds to reach that speed. Forces of this magnitude outmatch our current helmet standards and likely affect the mortality rate of avalanche victims.
Another issue arises when backcountry enthusiasts take their helmets off to climb, or “skin,” uphill. The rate at which backcountry skiers and snowboarders are caught in avalanches while ascending vs descending is unclear, with opinions ranging widely from 10% to 50% among avalanche experts (informal poll of avalanche forecasters and experts; anecdotal, not studied). The common practice of lashing a helmet to your backpack while ascending and being caught in a slide affords no benefit to the user. Helmets should be worn at all times (including skinning) to have a measurable impact.
A logical question then might be, is there any harm in helmet use? On the surface, this seems to be heretical. But if one digs past the assumptions, shortcomings begin to emerge. If protective equipment takes precedence over education, decision making, and other preventive behavior strategies, then there can be potential harm. Arming oneself with the latest beacon, probe, airbag, Avalung, and helmet are no substitute for practicing safe travel skills, terrain selection, snowpack evaluation, and rescue protocols. I am concerned that our culture that “treats every disease with a pill” all too often chooses gadgets over behavior modification and education. Outfitting oneself with all of the latest technology can bolster risk taking and confidence. 9 The phrase “energy-drink culture” permeates a large portion of the targeted demographic, and has been used to describe prevailing attitudes toward risk.
It goes without saying that helmets will protect against lacerations, contusions, possibly fractures, and moderate speed (less than 15 miles/h) head injuries. Protection against concussions is debatable. The likelihood of lowering mortality in avalanche trauma when traveling at 60 to 80 miles/h wearing a current-technology helmet is highly unlikely. It is my hope that in the future we may see helmet technology improve to the point where they can prevent serious TBI, and be worn at all times, including while ascending.
In the meantime, to decrease avalanche fatalities from trauma, we should be emphasizing prevention strategies with avalanche education and skills practice. Safety helmet recommendations should be second or third tier, and the inherent limitations of helmet technology need acknowledgment. The lack of consistent evidence for preventing serious TBI among skiers and snowboarders and decreasing the fatality rate will hopefully spur improved helmet safety standards and effectiveness, science on the issue, and, subsequently, lives saved.