Analysis of Ankle Deflection During a Forward Fall in Snowboarding

Abstract

Toward the general goal of preventing ankle injuries in snowboarding accidents, the objective of this project to develop a dynamic system model of a snowboarder and assess which model parameters, particularly those attributed to the boot, most strongly influenced ankle deflections during a forward fall. To satisfy this objective, a system model was created that included the rider, the boots, the snowboard, and the snow as components. Through dynamic simulations, peak ankle deflections were computed over realistic ranges of input parameter values for each of the model components. Defining sensitivity as the total change in peak ankle deflection over the range of a particular parameter studied, results indicated that the peak ankle deflection was most sensitive to the boot stiffness. Although lower, the sensitivity of the peak ankle deflection to the snow model parameters was still significant, being roughly half of the boot sensitivity. Increases in both snow stiffness and snow damping caused higher ankle deflections. Variations in both snowboard stiffness and anthropometric parameters had little effect. Due to the strong dependence of ankle deflection on boot stiffness, the potential exists for mitigating the ankle injury problem through judicious design of the boot.

In-area and backcountry snowboarding: medical and safety aspects

“…Releasable bindings are universally not recommended by researchers because of the potential for a severe knee injury with the release of only 1 foot. [8][9][10][11][12]16,[18][19][20] One injury particular to the lower extremity of a snowboarder is the fracture of the lateral process of the talus, called snowboarder's fracture. Several authors cite dorsiflexion and inversion of the rear foot as the mechanism leading to injury.8,13,18,20,21 However, since most ankle injuries occur to the lead foot, dorsiflexion and eversion of the forward foot is another likely mechanism.…”