出版社：Japan Society of Physical Education, Health and Sport Sciences
摘要：The purpose of this study was to investigate differences in the leading distance of the handle and handle movement of the hammer throw between competitors at different record levels during the turn phases, and the body movement required to obtain the handle leading distance. Forty-four male throwers (throwing record: 80.50-44.17m) participated in the study. Their throwing motions were videotaped using high-speed VTR cameras, and three-dimensional coordinates were calculated using a DLT method. Kinematic parameters calculated included the hammer head speed, the leading distance of handle, the handle velocity and velocity at the midpoint of the 2 shoulder joints using a rotating plane coordinate system where Xicr is the hammer head speed direction and Yicr is the direction connecting the hammer head and the instantaneous rotation center. We also investigated differences in the calculation parameters between an “Excellent” group（n=18, 74.77±4.30 m）and a “Normal” group (n=26, 55.80±5.96 m). The basic findings were as follows: (1) There was no significant difference between competitors at different record levels in the magnitude of the handle leading distance. The “Excellent” group showed a higher handle velocity in the Xicr direction than the “Normal” group during the turn phase. (2) Handle velocity in the Yicr direction was obtained mainly by increasing the midpoint of the shoulder joint velocity due to the trunk back lean during the double support phase (DSP). Since the increase and decrease in the handle leading distance are consistent with the increase and decrease of handle velocity in the Yicr direction, back lean of the trunk may increase the handle leading distance. In addition, generation of the handle velocity in the Xicr direction was achieved mainly by rotational movement of the body.
关键词：turn phase;ターン局面;leading distance of handle;ハンドル先行距離;handle velocity;ハンドル速度
