Injury surveillance to implementation: Strategies to ameliorate alpine skiing and snowboarding injuries in New Zealand
Snow sports injuries in New Zealand cost the government no-fault insurance scheme $20.5 million in 2014, accounting for 5% of sport and recreation claims. Cost in terms of quality of life may be much greater, as an individual’s well-being potentially affected by injury over months or years. The question of interest in this thesis centred on finding strategies to ameliorate such injuries. Review of the literature (Chapter 2, 5, 7) describes aetiology, injury mechanisms, the playing surface, equipment standards and injury prevention strategy development processes. To formulate strategy an injury prevention model Translating Research into Injury Prevention Practice (TRIPP) six-stage framework underpins thesis progression from epidemiological to experimental studies to injury-prevention strategy implementation.
Chapter 3 injury surveillance, describes the size and nature of the injury problem in alpine skiing and snowboarding. Analysis of ski area National Incident Data (NID) determined New Zealand injury rates of 3.2, 3.3, 3.4, 2.7 and 3.1 per 1000 skier/boarder days respectively (2010 – 2014). Two-thirds of first injury presentations, mostly sprains, bypassed mountain clinics; important information for determining targeted injury prevention programmes. Knee injury commonly occurred, more in skiers than snowboarders or tubing/hiking: 76%, 21%, and 3% respectively. Intermediate skiers were 1.6 times more likely to sustain a knee injury with non-release of ski-bindings in hard and soft snow.
Chapter 4 (TRIPP stage 2) aimed to determine factors that may impede ski-binding release. Analysis of standards of practice found only 10% of ski technicians met international standards. Torque testing to mitigate the risk of binding malfunction or incorrect set-up was uncommon. Over a third of the time, weight, an essential characteristic for the accurate determination of release values was not acquired.
Chapter 5 established equipment risk via random torque tests. Class III deviations ± 45% from the tolerance threshold for release warranting removal (8%) and Class II (48%) deviations ± 30% to ± 45% needed corrective action. Ski-binding heelpieces with two or more seasons use were nine times more likely to be out of tolerance than those with only one season of use. The common industry practice of retiring rental skis after three or four season’s use was an inadequate safety measure.
Binding self-release manoeuvres and self-adjustments identified as possible alternative solutions to increased labour and torque-testing plant costs, was the focus of experimental Chapter 6. Recreational skiers 14 years and over performed tests in ideal conditions (TRIPP stage 4). Of those that self-released only 28% released on ISO recommended release torques, all other skiers only released when the ski-binding settings were lighter than recommended. Additionally, there was no easy to use ski-boot wear and tear grading system highlighting a gap in existing standards.
Chapter 7 described the mountain implementation context (TRIPP stage 5) and detailed strategy implementation (TRIPP stage 6). The five-year injury prevention strategy developed in the thesis adopted by Ski Areas Association New Zealand will harness injury prevention efforts going forward. The new snow safety code, a completed first year strategy action seeks to address part of the injury prevention puzzle.