Joint loading, such as join forces and moments, needs to be investigated as fundamental information for prediction and analysis of skating-related musculoskeletal injuries. However, there is a lack of previous biomechanical studies due to technical difficulties in measuring three-dimensional motion data and ground reaction force data in the ice rink. A wearable motion analysis system with inertial sensors and in-shoe pressure sensors was recently developed. In this study, the knee joint kinematics and kinetics during shorttrack speed skating were investigated based on the data obtained from the wearable motion analysis system. The magnitudes of the estimated joint force and moment results were compared with those in the side-step cutting motion, in which non-contact anterior cruciate ligament (ACL) injury is common. The result indicates that the knee valgus moments in the gliding phase and push-off phase were similar to that in the side-step cutting motion. The knee internal rotational moment during the gliding phase and push-off phase were much higher than that measured during side-step cutting. It is necessary to note the high internal rotational moments during the skating in order to prevent any possibility of ACL injury.