Reducing the risks for traumatic and overuse injury among competitive alpine skiers

To achieve success, skiers attempt to optimise various biomechanical parameters (eg, trajectory, velocity, interaction between the skis and snow, energy) that influence performance, but this increases risk of injury. It is therefore not surprising that injuries are common among alpine skiers. To reduce the injury rate, the International Ski Federation (FIS) regulates ski length and width, sidecut radius, and the distance between the foot and ground. In the case of slalom skis, only the minimal waist width is regulated (≥63 mm), while in other disciplines the maximal waist width is regulated by FIS (typically ≤65 mm). On hard snow, wider skis are associated with an elevated risk for injury, so we suggest that it may be wise to revise this FIS regulation. Measures concerning the geometry of skis implemented recently have contributed significantly to the 26% reduction in absolute injury rate (injuries/100 athletes/season) (risk ratio 0.74, 95% CI 0.63 to 0.87). We acknowledge that new regulations concerning helmets, the development of wearable airbags, and an enhanced awareness of the influence of external conditions most likely have contributed as well. At the same time, additional approaches designed to elucidate the multifactorial causes of injury are warranted. Since it appears impractical to regulate other properties of the skis (eg, bending/torsional stiffness, edges and running base) during official competitions, we propose that the following measures might improve safety in connection with competitive alpine skiing. IMPROVE THE SAFETY-RELEASE IN SKI BINDINGS At present, the largest proportion of World Cup injuries involves the knee. To avoid inadvertent release, the safety-release in bindings is set considerably higher than the International Organization for Standardization (ISO) standard. If the torque and/or force required to open the ski binding when needed (eg, when an accident occurs) is too high, extensive torque is transferred to the knee joint. The mechatronic safety-release designs, that is, designs synergistically integrating mechanics, electronics and control theory to implement the knee biomechanically safe loading envelope, proposed for recreational skiing or even an emergency release that can be triggered manually might also be suitable for competitive skiers. A mechatronic design could include parameters such as knee angle and/or muscle activation into the algorithm that governs release. For example, this approach could be used to address injuries to the ACL caused by the ‘dynamic snowplough’ or ‘landing backweighted’mechanisms.