This study reports a coaching case of a men's hammer throw athlete (abbreviated to “T athlete” after this) who had a problem with the acceleration of the hammer during the turn phase. T athlete’s personal record was 45.75m at the start of coaching. The theme of the training program was “hammer throw without using preliminary swings”. And T athlete practiced to accelerate the hammer during the turn phase. The training was carried out for about three and a half months. The procedure of the approach was divided into two stages. The approach ① was the 1st training process until T athlete learned “the hammer throw without using preliminary swings”. The approach ② was a training process after learning “the hammer throw without using preliminary swings”. During the approach ①, T athlete was able to learn the timing to accelerate the hammer from the right back during “the hammer throw without using preliminary swings”. In addition, the approach ② conducted the inclined plane of the hammer orbit of the actual throw to get closer to the one of “the hammer throw without using preliminary swings”. Finally, T athlete improved the personal record approximately 7m (45.75 to 52.67m). “The hammer throw without preliminary swings” is considered to be effective as one of the convincing training method to improve the turn technique of hammer throw.

    The purposes of this study were to investigate load characteristics of the throw with the competition hammer (7.26kg) and the heavier hammer (8.0kg). Sixteen male hammer throwers threw the competition hammer and the heavier hammer with their maximum effort. Utilizing three high-speed video cameras (300fps), three-dimensional coordinates of the hammer head and left middle metacarpophalangeal joint were obtained using the direct linear transformation method. Main results were as follows: 1) The maximum centrifugal force of each phase in the heavier hammer was significantly higher than that of competition hammer during double support phase (DSP) of 3^rd and 4^th revolution. However, significant difference was not found in the average centrifugal force. 2) The centrifugal force in the heavier hammer was significantly higher than that of competition hammer during 14％－23％ and 47－51％ of DSP4. 3) Thirteen throwers showed positive values and three throwers showed negative values of force increment (absolute difference of maximum centrifugal force between the heavier hammer and the competition hammer). These results indicate that throwing the heavier hammer causes load increment, which is intrinsic purpose of resisted training.

〔目的〕本研究は片足立位（I），前方への片足踏み込み（II），台からの片足踏み込み（III）の急性期と安定期の重心動揺を比較し，足部アライメント指標（FA）との関係を検討することを目的とした．〔対象と方法〕対象は大学野球選手64名とした．FAは内側縦アーチ高率，第1・第5趾側角，開張角，足幅／足長比とし，重心動揺指標は足圧中心（COP）軌跡速度，重心動揺面積とした．〔結果〕急性期のCOP軌跡速度は条件I，II，III間に有意な差が認められたが，安定期はIIとIIIとの間に有意差を認めなかった．IIIではFAとCOP軌跡速度との間に有意な相関関係を認めなかった．〔結語〕急性期の重心動揺は身体重心方向と衝撃力が影響し，安定期は足部接地前の準備動作が影響した可能性がある．IIIは足部より上位関節が重心動揺と関係した可能性が推察された．