On the analyzing results of three lifting movements of the weightlifters in Tokyo Olympic Games, mainly / 体力科学

ABSTRACT

High ranking Japanese weightlifters in Tokyo Olympics and high ranking adults and high school students in the 20th Japan National Athletic Meeting were chosen for the subjects. We made research about them for many patterns of movements of the Olympic three lifts which seemed to be the most reasonable way in analyzing the movements of the lifters, by comparing the results which were gotten by the 16 mm 64 frames side filming method with their official records and lifting marks. This led to the following conclusion:<BR>1) At the begining of the clean, dead-lift, for the press the excellent lifters accelerate the bar at a higher speed, but the increase of speed after the begining is not so much. The Olympic lifters pull up the bar bending more forward, at a knee level. But excessive forword bending makes many lifters fail to clean weell.<BR>2) Exellent lifters bigin pressing at a high speed by vigorous extension of their body, Less-trained lifters can not use vigorous extension of their body because of presing forward, or comming down the bar again, and bending the kenee joints.<BR>3) In the snatch excellent lifters pull up the bar at a higber speed to the knees, but they at a speed of lower acceleration from the knees. Even if they are excellent lifters, they often fail to snach in the case of pulling with over-acceleration at that point. It is inportant also in the snatch to use effectively the power of lower ports of the body.<BR>4) It is evident from the loci of the bar that, if the bar travells upward vertically, or near vertically, squat-style lifters need to jump back properly In the case they do not jump back the for moves back and forth excessively, many lifters fail to snatch if they jump back too much.<BR>5) In the clean for the jerk an increasing acceleration in dead lift phase during clean is necessary to become a successful lifter. It is necessary to concentrate the power of the lower parts of the body as much as possible to accelerate on the bar to a knee level. From the knee level exce lent lifters pull the bar by using the pulling power of shoulders more aectively. The barbell falling down from the dead point must be held moderately not to fall down at a high speed.<BR>6) If lifters overstrain the shoulder muscle groups and arms at the starting of the jerk and can not dip their body well in accordance weith dropp ing movement of the bar, they will fail to jerk.<BR>7) The dropping speed of the bar at the first step of the jerk must be marked more carefully at the second phase than at the first phase. Many who make it increase more at the second phase will fail to jerk.<BR>8) The bar of the excellent jerker goes up with very high speed at the begining. But of the speed of the bar after that there is no diffrence between lifters.