【作者】 陈民盛；

【导师】 金季春；

【作者基本信息】 北京体育大学 ， 运动人体科学， 2005， 博士

【摘要】 Clap式冰刀的使用开创了速滑运动一个新的纪元。自第18届冬奥会(1998)至今所有世界记录均被刷新就是最好的验证。尽管高海拔(盐湖城1227m)及室内冰场提供了创造优异比赛成绩的外部条件,但是,Clap式冰刀的益处不容质疑。可以说新式冰刀的问世对传统蹬冰动作技术原理及其训练方法提出了新的挑战,引起了人们的高度重视。虽然从1997年开始Clap式冰刀被引入我国并且公认为:Clap式冰刀与传统冰刀相比具有延长蹬冰作用时间;提高踝关节的灵活性;增大下肢关节蹬伸幅度;保持冰刀全刃与冰面接触和原有的滑行方向以及蹬冰方向,使之在踝关节充分跖屈的情况下结束蹬冰动作等作用;但也存在着新技术是:向侧后蹬冰还是向后蹬冰;蹬冰最后阶段的伸膝、踝动作是自然动作还是主动动作的结果;蹬冰过程中的重心位移方向仅是横向(法向)移动还是纵(切向)横(法向)兼有等重要技术环节上的认识分歧。为了有效阐述Clap式冰刀的蹬冰机制,本研究采用运动生物力学方法,通过对影响速度滑冰滑行速度的技术要素分析,确立正确的弯道蹬冰技术概念,阐明动作技术的关键环节,明确速滑蹬冰动作加速理论的内涵,建立优秀运动员的弯道技术参数体系,进而揭示Clap式冰刀弯道蹬冰动作技术的生物力学原理。本研究结论如下:1 Clap式冰刀弯道蹬冰动作技术原理Clap式冰刀弯道蹬冰动作技术原理主要体现在两个方面:一是通过提高踝关节的灵活性来改变下肢各关节的发力性质;二是通过冰刀结构的改变来揭示速滑蹬冰技术动作加速理论的适用条件。核心是提高踝关节的灵活性。具体表现为:(1)Clap式冰刀通过“铰链”连接结构,提高了踝关节的自由度,改变了传统冰刀在蹬冰过程中主要发挥髋、膝关节的力量,而难以利用踝关节力量的弊端,在增加做功环节的同时又加大了膝关节的工作范围。(2)通过提高踝关节的灵活性来改变原有下肢各关节发力特征,最终提高身体滑行速度。(3)踝关节运动幅度的提高改变了原有蹬冰过程中重心主要做横向(法向)移动而难以纵向(切向)前移的弊端,使重心沿切线方向的主动性前移成为可能。2速滑蹬冰加速理论的适用条件本次研究认为:以往提出的加速理论,在反映高水平运动员加速能力时是有条件的;而且,单纯从获得速度改变量大小的角度来推断蹬冰加速的机制,并不应是使重心加速的唯一条件;重心前移程度(切向)与合理的侧蹬冰时机相结合是获得最佳加速度的前提,它反映了支点与重心间力的相互作用关系和蹬冰动作的加速条件。正是Clap式冰刀的这种特有结构为重心前移提供了可能,体现出现代速滑蹬冰加速理念在实践中的合理运用。3动态支撑方式中频幅组合的模式特征本研究首次在周期性竞速项目的步幅、步频与步速关系研究中提出区分定点支撑方式与动态支撑方式的概念。通过对不同滑行速度中频幅组合与步速之间的关系分析,比较了动态支撑方式与定点支撑方式中的差异在频幅组合上所表现出的异同性。结果发现:从低速向高速滑行过程中频幅组合在步频与步速关系中,动态支撑方式遵循定点支撑方式的变化规律,满足步频对步速的曲线凹面向上的函数关系,两者具有一致性;但在步幅与步速关系中,动态支撑方式却与定点支撑方式相反。定点支撑方式表现为随着速度的提高步幅也增大(在极限速度条件下或保持不变或略有减小);动态支撑方式表现为随着速度的提高步幅减小的变化规律。这一结果揭示出:支撑方式(动态支撑和定点支撑)不同时,在步幅与步速之间的制约关系中,随着速度的提高步幅也增大的规律是有条件的,应根据动、定点支撑方式的性质加以区别对待。更多还原

【Abstract】 In the international world of speed skating, the use of Clap skates has ushered a new era. The fact that all of the world records before 18th Olympic Winter Games were beaked is the best evidence. Although high altitude (the Salt Lake city--1 227m) and the indoor ice rink provide the external conditions for the excellent result of the competition, the benefit of Clap skates should not be doubted. The appearance of the new type of skates has challenged the traditional skill theory of push--off on the ice and the traditional training method, which has attracted people’s attention. Since the new type of skates has been introduced into China and is thought to be: compared to the traditional skates, the Clap ice-skates has prolonged the time of push--off on the ice; it has elevated the flexibility of the ankles; it has increased the width of push--off and extending of the lower limbs; it keep the blade of the skates in touch with the ice surface and the original skating direction parallel with the direction of push--off on the ice, thus it finishes the action of jigging on the ice under the conditions that the ankle is fully bent; however, there still exists the new technique: push--off towards the rear of flank or directly backwards; the bent of the knees and the movement of the ankle in the last phase is the natural action or active action; the translocation of the center of gravity is only the crosswise movement or combined with the longitudinal movement. The recognition of many important skills is still under dispute. In order to explain the mechanism of push--off on the ice of the Clap ice-skates clearly, this research applies the method of Applied Mechanics in Biomechanics. Through the technical element analysis that influences the speed of skating, this article tries to establish the right technical concept of push--off on the ice on the curve, explain the key link of the movement skills, make clear the content of the accelerating theory of the action of push--off on the ice and establish excellent athlete’s parameter system of the skills of skating on the curve. Furthermore, it tries to uncover the biomechanical principle of push--off on the curve of the Clap ice-skates.The result of this research is as follows:I. The technical principle of push--off on the ice curve of the Clap ice skates.The connotation of the technical principle of push--off on the ice curve of the Clap ice skates embodies in two aspects: First, elevate the flexibility of the ankle to change the nature of the strength-exerting of the joints of the lower limbs; Second, reveal the applicable conditions of the accelerating theory of push--off on the ice of speed skating through the change of the structure of the skates. The core is to elevate the flexibility of the ankle. Concrete details are:(1) The Clap skates elevate the flexibility through the link structure of the“hinge”, thus change the malpractice of traditional push--off process which mainly depends on the power of the hipbone and the knee, and thus obstruct the use of the power of ankle. The Clap skates add the exerting strength and extend the working scope of the ankle.(2) Through elevating the flexibility of the ankle, change the strength-exerting character of the joints of the lower limbs in order to accelerate the body skate speed.(3) The elevation of the flexibility of the ankle avoids the malpractice that the gravity center during the process of push--off on the ice mainly goes crosswise and is difficult to shift longitudinally and makes it possible that the gravity center actively moves forward along the direction of the tangent.II. The applicable conditions of the accelerating theory of push--off of speed skating.The research shows that the former accelerating theory is conditional when reflecting the accelerating ability of the high-level athletes. Besides, the amount of accelerating the speed to infer the accelerating mechanism of push--off should not be the only condition to accelerate the gravity center. The scope of the gravity center moving forward combined with the suitable opportunity to push--off on the ice side wards is the premise of acquiring the optimum speed. It reflects the interactive relationship between the fulcrum and the gravity center and the accelerating condition of the push--off. It is the Clap ice-skates’unique structure that makes the gravity center moving forwards possible. It embodies the reasonable application of the accelerating theory of ice-jigging of modern speed skating in the practice.III. The model characteristics of the frequency and width combination of motional supporting patternThis research, for the first time, put forwards the concept distinction between the fixed point supporting pattern and the motional supporting pattern in the study of the pace width, pace frequency, pace speed of the cyclical speed competition. Through the analysis of the relationship between the combination of frequency and width and the pace speed in the different skating speed, we find out the similarities and differences in the aspect of frequency and width combination by comparing the motional supporting pattern with the fixed point supporting pattern. The result shows: frequency combines with width in the relationship between pace frequency and pace speed in the process of speed skating from low-speed to high-speed; the motional supporting pattern observe the changing rules of the fixed point supporting pattern, fit in with the function relation of pace frequency’s the concavity upward curve to pace speed, and the two entail unity; but in the relationship between the pace frequency and the pace speed, the motional supporting pattern and the fixed point supporting pattern contradict. The fixed point supporting pattern shows that the pace width increases alongside with the acceleration of the speed. (Under the condition of the maximum speed, it remains unchanged or a little reduced); the motional supporting speed shows that the pace width reduces alongside with the acceleration of the speed. The result reveals: when the supporting pattern is different (the motional supporting and fixed point supporting), in the interactive relations between pace width and pace speed, the pace width increasing with the acceleration of the speed is conditional. So we should distinct the motional supporting pattern with the fixed point supporting pattern.更多还原