Cross-country skiing skating technique discrimination using a high-precision kinematic GNSS

Abstract

Cross-country skiing is broadly divided into classical and skating techniques, and skating techniques combines several types of sub-techniques such as quick skating (V1), super skating (V2), and rabbit skating (V2a). These sub-techniques require you to choose the most appropriate technique for the occasion in consideration of the inclination of the course, snow quality, speed, and your own physical strength (upper body power). Purpose: We use a high-precision kinematic GNSS to discriminate between the sub-techniques of the skating technique. Methods: One male athlete who had represented the cross-country skiing Japan the cross-country event at the Winter Olympics was analyzed during skating style 3.0 km time trial recorded with a high-precision kinematic GNSS attached to the skier’s head. A video camera was mounted on the lumbar region of the skier to detect the type and number of cycles of each technique used during the entire time trial. Based on the GNSS trajectory, distinct patterns of head displacement (up-down head motion and moving direction) for each skating technique (e.g., V1, V2 and V2a) were defined. Results: The %Match was high: 101.5 % for V1, and 94.1 % for V2, and 97.1 % for V2a, and 98.8 % in total. Conclusions: It was suggested that a high-precision kinematic GNSS can distinguish the sub-technique of the skating techniques by combining it with the trajectory analysis of the left and right movements as well as the up-and-down motion of the head.