Design and testing of an innovative data acquisition system for ski touring / alpine ski boots loads and deflections field measurements

Interest for winter sports like alpine ski and ski touring is increasing in recent years. Engineers and biomechanicists are interested in the study of kinetics and kinematics of skiing for their purposes. From an engineering side, ski boot is an important piece of equipment since it transmits loads between athlete and ski. The present study aims to measure and interpretate data from skiing tests in outdoor tests. To do so, a transferrable load cell system has been developed to measure the tri axial forces and torques passing through the front and rear bindings both for ski touring and alpine ski. Ergal platforms have been designed to provide a solid and compact connection between ski, loadcells and bindings. Moreover, custom angular sensors have been prototyped and positioned over the ski boot to measure rigid and elastic deformations. With respect to past studies, our system is more light and compact, and is less influencing the skiing performance. The system has been validated in indoor tests, and then gave to athletes and ski professionals to study ski touring, alpine ski and racing ski during outdoor tests on field, both on groomed and fresh snow. Data from outdoor tests were analyzed to obtain total ground reaction force vector, center of pressure position, and torques on the skier's ankle. Kinematics allowed to study range of motion during uphill in ski touring and relative movement between boot components and leg during skiing. Results of this study could be useful for ski industry to develop more performing gear, as well to reserchers in ski biomechanics. Future developments could include the study of loads in ski touring conditions off-piste, the study of ski injuries and the analysis of downhill skiing technique.