Kinematic Analysis of Lower Extremity and Evaluation of Skill of Skier Using Parameters of Inertial Sensors During Ski Simulator Exercise

Abstract: In this study, joint angles of the lower extremity and inertial sensor data such as accelerations and angularvelocities were measured during a ski simulator exercise in order to evaluate the skill of skiers. Twenty experts andtwenty unskilled skiers were recruited for the study. All expert skiers held the certificates issued by the Korea SkiInstructors Association. A three-dimensional motion capture system and two inertial sensors were used to acquirejoint movements, heel acceleration and heel angular velocity during ski simulator exercises. Pattern variation valueswere calculated to assess the variations in ski simulator motion of expert and unskilled skiers. Integral ratio of rollangular velocity was calculated to determine the parallel alignment of the two feet. Results showed that ski expertsshowed greater range of motion of joint angle, peak to peak amplitude(PPA) of heel acceleration and PPA of heelangular velocity than unskilled skiers. Ski experts showed smaller pattern variations than unskilled skiers. In addi-tion, the integral ratio of roll angular velocity in ski experts was closer to 1. Inertial sensor data measurements duringthe ski simulator exercises could be useful to evaluate the skill of the skier.Key words: ski simulator, inertial sensor, kinematics