A KINEMATIC COMPARISON OF THE UP START AND DOWN START TECHNIQUES USED IN IN-LINE SPEED SKATING

Abstract

The purpose of this study was to kinematically compare the up start and the down start techniques used in in-line speed skating. Twelve elite subjects were videotaped with two 60 Hz cameras while performing two up starts and two down starts each. The fastest performance of each subject in each style was analyzed utilizing a Peak5 Motion Analysis system. Three dimensional coordinates of 14 body points of each subject were calculated by combining the images of the two cameras, utilizing the direct linear transformation (DLT) technique. The raw position data were digitally filtered before being submitted to further analysis. MANOVA revealed significant (pc.05) differences between the two techniques at the beginning in: 1) height of center of gravity (COG), 2) knee joint angle, 3) hip joint angle, 4) push-off angle, 5) angle of lean, and 6) angular velocity of the hip joint. These differences were not significant at the end of the analyzed time period. In addition, there were no significant differences between the two techniques in displacement of the COG during the time period studied (1.52 seconds) and maximum linear velocity and acceleration attained by the subjects. It was concluded that neither of the two in-line skating techniques is superior to the other.