The purpose of this study was to identify an effective technique in the support leg extension for sprint speed skaters. Ten junior and 9 senior elite male skaters who participated in a 500 m race were videotaped with 2 synchronized high-speed video cameras (250 fps) positioned at the middle of the home straight (～50 m from the start line); the recorded images were analyzed using a panning direct linear transformation technique. The three-dimensional coordinates of the segment endpoints and blades were determined to calculate the kinematic variables during the right stroke. On the other hand, skaters performed a single leg skate jump test on a tartan track. The ground reaction forces and three-dimensional coordinates of the segment endpoints were determined to calculate the kinetic variables at the right support leg by using an inverse dynamics approach. During the first half of the stroke in the ice skating performance, the change in the forward displacement of the center of mass in the senior group was greater than that in the junior group; this was attributable to the smaller segment angle of the shank in the support leg for the senior group. This indicates that a greater anteversion of the shank is a technical characteristic of an excellent skater. While the vertical ground reaction force in the single leg skate jump test greatly increased, the senior group maintained a smaller segment angle of the shank and a greater knee extension torque in the support leg. On the other hand, knee extension torque in the support leg for the junior group decreased temporarily owing to increase of the segment angle of the shank. Thus, the ability to maintain a greater knee extension torque with a greater load in the lower limb is an important factor for acceleration during the straight skating in the first half of the 500m race.