Mechanism of the Head Collusion Accident of Swimming Dive and Making the Manual for Safe Diving

游泳跳水运动中头部与池底的碰撞是跳水动作失败的结果。它往往发展成瞬间影响死亡伤残者生命的事故。关于这些产生原因和案例的报道很多。然而，很少有报告表明对活体的损害和影响的程度变得清晰。这项研究使用了人体和假人。以日本的学校游泳池设施为例，测量了水底碰撞的冲击力。此外，本研究还探讨了游泳启动时的运动模式，并考察了身体各部位的动作对运动模式变化的影响。使用高速录像机系统，以22个类别的游泳出发成绩为尺度，对飞行动作进行评价。一般池底碰撞的接触时间为0.02秒或更短。当设定下水条件，使假人头部可能与测力板剧烈碰撞时， ...更多信息 检测到最大冲击力11907N和最大冲击加速度113G。显然，即使构造缓冲材料，减小冲击量，损伤也是相当严重的。1)起跳动作有一个一般的发展过程，即从跳跃式到击腹式，再到俯冲式。2)关于躯干的倾斜度，飞行对入水的影响大于设定位置。3)在入口处保持躯干直立的儿童向上推离木块，缩短了飞行距离。（4）证实了在飞行过程中四肢的前后伸展是发展起步运动所必需的。（5）入水时，肩关节的屈曲和点头是由击腹向入水转变的必要条件，据此编制了安全入水教学手册。少

The head collision with the base part of the pool results from the failure of diving movement in swimming. It often develops into the accident which instantaneously affects life of die disablement. The report concerning these generation causes and cases is done a lot. However, there are few reports by which the damage to the living body and the amount of the impact become clear. This research used the human body and the dummy. The impact in the bottom of the water collision was measured supposing the school pool facilities in Japan. Moreover, this study investigated motor patterns in swimming start and examined movements of each part of body influencing the change of motor pattern. Using high-speed VTR system, the flight motions were evaluated by the scale of 22 categories in swimming-start performance.The contact time of the collision of the general pool bottom was 0.02 seconds or less. When launching condition was set so that the dummy head may violently collide with the force plate, … More maximum impulsive force 11907N and maximum impact acceleration 113G were detected. Clearly the damage is considerably serious even if the buffer material is constructed and the amount of the impact is reduced.By the motor patterns analysis, following results were obtained. 1)Starting motions showed a general process of development, which proceeded from a jumping pattern to a hitting-the-belly pattern, then to the pattern of a plunge dive. 2)Regarding inclination of the trunk, the flight had a greater influence than the set position on the entry. 3)The children who kept the trunk upright on the entry pushed off the block in an upward direction and shortened flight distance. 4)It was confirmed that stretching four limbs in front and rear during the flight was necessary to develop the starting motion. 5)On the entry, the flexion of the shoulder joint with nodding the head seemed necessary for the change from hitting the belly to the plunge dive.Standing on these results, we made the teaching manual for safe plunge entry into water. Less