共查询到20条相似文献，搜索用时 78 毫秒
1.
Koyama H Muraki Y Ae M 《Sports biomechanics / International Society of Biomechanics in Sports》2005,4(2):113-129
In this study, we investigated the effects of inclined and raised flat boards on the take-off motion of the long jump to determine the effectiveness of these boards as training tools. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. Four different jumps were performed with in four conditions, all with their medium length run-up: a long jump with their normal technique, long jumps on upward inclined boards of two different inclinations (2.5 and 5.0 degrees), and a long jump on a raised flat board (0 degrees, 50 mm). The raised flat board enhanced the pivot of the body over the take-off foot, and reduced flexion of the take-off leg knee. However, the inclined boards did not produce the same effects as the raised flat board. The use of the inclined boards increased the vertical velocity of the centre of mass of the body at toe-off, resulting in increased airborne time. These results suggest that the raised flat board and inclined boards would be effective in improving long jumpers' techniques during the take-off and airborne phases. 相似文献
2.
Muraki Y Ae M Yokozawa T Koyama H 《Sports biomechanics / International Society of Biomechanics in Sports》2005,4(1):1-15
The aim of this study was to establish the functions of the support leg in the long jump take-off with a three-element mechanical model spring, damper, and actuator The take-off motions of eleven male long jumpers, with personal bests from 6.45 to 7.99 m, were videotaped at 250 Hz and ground reaction forces were simultaneously recorded at 1 kHz. A two-dimensional 14-segment linked model was used to collect basic kinematic parameters. The spring, damper and actuator forces were determined from the displacement and velocity of the centre of mass and from ground reaction forces. Large spring and damper forces were exerted, and absorbed the impact force immediately after the touch-down. The spring force was also exerted from 25 to 75% of the take-off phase. The actuator force was dominant in the latter two-thirds of the take-off phase. Statistically significant correlations were found between the spring force impulse and the knee flexion during the take-off phase (r = 0.699, p < 0.05), and between the knee flexion and the angular velocity of the thigh at the touch-down (r = 0.726, p < 0.05). These results indicated that the jumper should retain less flexion of the take-off leg knee to increase the spring force, after a fast extension of the hip, and use a more extended knee at the touch-down to prevent excessive knee flexion. 相似文献
3.
The aims of this study were to determine: (1) the modes of action of selected muscles of the supporting leg during the take-off of a running long jump; (2) whether the instant at which maximum knee flexion is recorded is a valid indicator of the instant these muscles change their modes of action; and (3) the relationships between the actions of these muscles and the change in the vertical velocity of the centre of mass during the take-off. Eleven elite, female long jumpers performed six jumps from a full-length approach. A model of selected muscles of the jumping leg was developed to estimate muscle-tendon lengths from segment positions obtained using cinematography. Only half of the muscles exhibited a lengthening-shortening sequence of activity. The instant at which maximum knee flexion was recorded was a poor indicator of when the muscles changed from eccentric to concentric activity. The more the vasti muscles were stretched, the larger the gain in vertical velocity; the longer the triceps surae muscles at touchdown, the more they were stretched, and the faster they were stretched, the larger the gain in vertical velocity. Enhancement through use of the stretch-shortening cycle did not make a significant contribution to vertical velocity via the actions of the vasti and triceps surae muscles. 相似文献
4.
运用影片拍摄及解析的方法对成绩在 6.30 m以上的 6名中国优秀女子运动员摆动腿在助跑最后一步和起跳过程中的运动学特征进行分析。研究表明,在助跑最后一步蹬伸阶段优秀女跳远运动员摆动腿髋的水平速度与水平速度增加值呈高度正相关;着板时,摆动腿摆动角速度与起跳脚水平速度呈高度负相关;起跳过程的缓冲阶段中,摆动腿的摆动使身体重心高度呈上升趋势,同时垂直速度持续升高,占腾起垂直分速度值的53.1％。 相似文献
5.
In this study, we measured the vertical and horizontal take-off forces, plantar pressures and activation patterns of four muscles (vastus lateralis, gluteus maximus, tibialis anterior, gastrocnemius) in 10 ski jumpers in simulated laboratory conditions when wearing either training shoes or ski jumping boots. We found significant differences in vertical (P < 0.001), horizontal (P < 0.05) and resultant (P < 0.001) take-off velocities and vertical force impulse (P < 0.01). We found no significant differences in the jumpers' initial take-off positions; however, the jumping boots condition resulted in a smaller displacement in the final position of the following joint angles: ankle angle (P < 0.001), knee angle (P < 0.001), hip angle (P < 0.01) and shank angle relative to the horizontal (P < 0.01). This corresponds with less electromyographic activity during take-off in both the gastrocnemius (300 to 200 ms and 200 to 100 ms before take-off) and gluteus maximus (300 to 200 ms and 100 to 0 ms before take-off). During the early take-off in the jumping boots condition, significantly more pressure was recorded under the heel (P < 0.001), whereas the forefoot was more highly loaded at the end of the take-off. Differences in take-off velocity (representing the final output of the take-off) can be accounted for in the main by the different use of plantar flexion, emphasizing the role of the knee and hip extensors when wearing jumping boots. We conclude that the stiffness of the structure of the jumping boots may result in a forward shift of pressure, thus limiting the effective vertical force. To avoid this pressure shift, the pattern of movement of simulated take-offs should be carefully controlled, particularly when wearing training shoes. 相似文献
6.
In this study, we measured the vertical and horizontal take-off forces, plantar pressures and activation patterns of four muscles (vastus lateralis, gluteus maximus, tibialis anterior, gastrocnemius) in 10 ski jumpers in simulated laboratory conditions when wearing either training shoes or ski jumping boots. We found significant differences in vertical ( P ? 0.001), horizontal ( P ? 0.05) and resultant ( P ? 0.001) take-off velocities and vertical force impulse ( P ? 0.01). We found no significant differences in the jumpers' initial take-off positions; however, the jumping boots condition resulted in a smaller displacement in the final position of the following joint angles: ankle angle ( P ? 0.001), knee angle ( P ? 0.001), hip angle ( P ? 0.01) and shank angle relative to the horizontal ( P ? 0.01). This corresponds with less electromyographic activity during take-off in both the gastrocnemius (300 to 200 ms and 200 to 100 ms before take-off) and gluteus maximus (300 to 200 ms and 100 to 0 ms before take-off). During the early take-off in the jumping boots condition, significantly more pressure was recorded under the heel ( P ? 0.001), whereas the forefoot was more highly loaded at the end of the take-off. Differences in take-off velocity (representing the final output of the take-off) can be accounted for in the main by the different use of plantar flexion, emphasizing the role of the knee and hip extensors when wearing jumping boots. We conclude that the stiffness of the structure of the jumping boots may result in a forward shift of pressure, thus limiting the effective vertical force. To avoid this pressure shift, the pattern of movement of simulated take-offs should be carefully controlled, particularly when wearing training shoes. 相似文献
7.
跳高起跳垂直速度的生物力学研究 总被引：3，自引：0，他引：3
采用两台SONY摄像机对我国优秀男子跳高运动员的试跳进行现场同步拍摄，选取有关运动学参数与国外优秀运动员做对比分析。研究结果：我国运动员起跳着地瞬间质心向下的垂直速度较小，符合我国运动员的身体特点；在起跳阶段，我国运动员双臂和摆动腿的摆动速度与优秀运动员相比较低，主要与起跳腿的专项力量素质有关；我国运动员起跳时间与国外优秀运动员相比较短，与蹬伸距离较短有关。相对缩小起跳的缓冲时间，有利于提高起跳的垂直速度。决定跳高起跳垂直速度的诸因素均与起跳腿的专项力量素质有关。 相似文献
8.
中外优秀男子跳远选手起跳阶段技术对比 总被引：7，自引：0，他引：7
张新 《上海体育学院学报》2000,24(3):67-69,72
运用文献资料和比较分析的研究方法,对中外优秀男子跳远选手起跳阶段的技术进行研究。结果表明,我国选手的技术差距并非是水平速度损失率大,相反速度的利用率明显优于外国优秀选手;而起跳角度偏小。起跳腾起垂直速度慢等问题,是影响我国优秀男子跳远选手提高成绩的关键。 相似文献
9.
我国男子跳远运动水平落后原因剖析 总被引：1，自引：0，他引：1
通过对中外优秀男子跳远运动员的比较分析发现,我国优秀跳远运动员身高普遍偏低;助跑绝对速度能力存在一定的差距;起跳瞬间水平速度损失较小,但垂直分速度过低,导致腾起角太小,影响了起跳效果.选材中注意选拔身材较高且具有较大速度潜力的运动员,同时在训练中倾向于发展跳远运动员在快速助跑中的起跳能力,是我国男子跳远运动在理论和实践中努力的方向. 相似文献
10.
11.
杜建国 《天津体育学院学报》2011,26(4):364-366
分析比较不同级别男子跳高运动员膝关节屈伸肌群离心收缩时峰力矩特点及差异。在首都体育学院生物力学实验室,采用德国ISOMED2000等速测试仪,对8名一级男子跳高运动员和8名二级男子跳高运动员膝关节肌群进行等速离心收缩测试,测试角速度60°/s、120°/s、240°/s,指标包括峰值力矩、相对峰力矩(峰值力矩/体重)、峰值力矩屈伸比。研究结果:(1)一级跳高运动员起跳腿膝关节屈、伸肌峰力矩较二级跳高运动员有显著性差异(P<0.05);(2)平均功率随给定运动角速度的增大而增大(P<0.01);(3)离心收缩峰力矩随给定运动速度的增加无显著变化;(4)离心收缩膝关节屈伸肌群峰力矩比值为0.60～0.63之间。结论:跳高运动员膝关节肌群等速测试结果的差异是造成一、二级跳高运动员成绩差异的原因之一。 相似文献
12.
对我国部分优秀男子跳高运动员起跳技术的运动学分析 总被引：18，自引：1，他引：17
通过三维摄影，对我国部分男子跳高运动员的起跳技术进行了分析。结果表明，我国运动员与世界优秀运动员在起跳技术方面存在着较大的差异，主要表现为前者在助跑与起跳衔接阶段的质心水平速度较低，倒1步身体内倾角度变化呈大—小趋势；在起跳阶段，起跳腿着地时的质心水平速度低，身体质心垂直加速距离较短以及起跳腿缓冲蹬伸时间比例不完全符合力学原理等。另外，我国运动员在起跳过程中普遍存在着起跳腿蹬伸不充分以及摆动腿摆速和摆幅偏小的问题。 相似文献
13.
Yasushi Kariyama Hiroaki Hobara Koji Zushi 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(2):187-200
This study aimed to clarify the differences between the horizontal single-leg rebound jump (HJ) and vertical single-leg rebound jump (VJ) in terms of three-dimensional joint kinetics for the take-off leg, while focusing on frontal and transverse plane movements. Eleven male track and field athletes performed HJ and VJ. Kinematic and kinetic data were calculated using data recorded with a motion capture system and force platforms. The hip abduction torque, trunk lateral flexion torque (flexion for the swing-leg side), hip external and internal torque, trunk rotational torque, and the powers associated with these torques were larger when performing HJ because of resistance to the impact ground reaction force and because of pelvic and posture control. Pelvic rotation was noted in HJ, and this was controlled not only by the hip and trunk joint torque from the transverse plane but also by the hip abduction torque. Therefore, hip and trunk joint kinetics in the frontal and transverse plane play an important role in a single-leg jump, regardless of the jumping direction, and may also play a more important role in HJ than in VJ. 相似文献
14.
采用文献资料法、录像解析法、数据处理法,对参加全国田径锦标赛女子跳远运动员(最后筛选取20名)空中技术特征进行研究,探讨空中技术与运动成绩之间的关系。结论认为:我国女子跳远运动员空中技术对起跳效果有影响。走步式空中技术能在起跳过程中通过紧密衔接的摆动腿加速前摆和制动前摆,加快起跳腿的缓冲和蹬伸动作速度,促进身体重心获得更大的垂直速度,而且水平速度没有更多的损耗,从而获得更大的腾起速度和腾起角,腾起时身体重心的垂直位置更高,最终取得优异成绩,促进跳远起跳技术朝着快速积极的方向发展。 相似文献
15.
对优秀男子跳远运动员踏跳阶段技术的运动学分析 总被引：1，自引：0，他引：1
董黎明 《上海体育学院学报》1989,(1)
为了寻找我院男子跳远运动员踏跳阶段的运动学变化因素,本文通过高速电动摄影机,对我院优秀男子跳远运动员最佳踏跳阶段的技术进行影片定量解析:(一)身体重心水平速度;(二)身体重心垂直速度。进而为进一步提高我院男子跳远成绩提供了参考依据。 相似文献
16.
我国优秀女子三级跳远运动员二、三跳起跳技术运动学特征 总被引：2，自引：1，他引：1
对8 名国内优秀女子三级跳远运动员二、三跳起跳技术影片解析结果表明,第二跳起跳时所获得的垂直速度小,腾起角小,这与起跳蹬伸时机晚和蹬伸不充分有关,同时与摆动腿大小腿折叠不紧、摆动速度慢和摆动幅度小有关。第三跳起跳过程中水平速度损失较多,但也获得了较大的垂直速度,这与起跳时着地角小和起跳角大及着地过程中脚扒地速度慢有关,同时与摆动腿摆动速度慢和摆动幅度小有关。8 名运动员第二跳距离百分比偏小。 相似文献
17.
目的:通过分析我国优秀男子跳台滑雪运动员实地起跳阶段运动学、起跳运动模式等指标,探究影响我国男子跳台滑雪运动员飞行距离的主要起跳因素。方法:1)选择8名我国男子跳台滑雪运动员作为研究对象,在日本长野县白马村K90跳台训练基地采集3次起跳阶段二维运动学数据,采用广义估计模型(GEE)分析影响飞行距离的实地起跳阶段运动学因素。2)截取平昌冬奥会排名前10的男子跳台滑雪选手决赛起跳阶段视频数据,采用单因素方差分析研究国内外运动员起跳阶段特定时刻肢体角度差异。3)实验室内使用1台Z camera高速摄像机和1块Kistler 9281EA测力台采集运动员静蹲跳(squat jump,SJ)、反向跳(countermovement jump,CMJ)、模拟跳跃(imitation jump,IJ)、下落跳(drop jump,DJ)的动力学及运动学数据,采用Pearson相关分析检验实验室内运动学及动力学指标与飞行距离间的相关性。结果:1)在实地起跳阶段运动学方面,起跳起始时刻躯干与助滑道夹角、小腿与助滑道夹角、髋关节角、膝关节角,以及起跳阶段的髋关节峰值角速度、膝关节平均角速度、起跳结束时刻膝关节角及髋关节角为飞行距离的影响因素(P<0.05)。2)在起跳阶段运动模式及力量特点方面,IJ重心最低处膝外翻指数(r=0.731)、DJ膝外翻最小值(r=0.713)、CMJ起跳阶段地面反作用力峰值(r=0.710)、CMJ蹬伸冲量(r=0.752)、SJ(r=0.723)及CMJ起跳峰值功率(r=0.762)均与飞行距离呈正相关。3)对比国内外运动员起跳阶段特定时刻肢体角度发现,国外优秀运动员起跳起始时刻小腿与助滑道夹角(53.54°±3.14°)显著小于我国运动员(57.62°±4.62°),出台瞬间小腿与助滑道夹角(58.22°±2.13°)显著小于我国运动员(65.59°±3.84°),大腿与助滑道夹角(73.28°±6.15°)显著大于我国运动员(58.77°±3.16°),起跳阶段结束时刻髋关节角度(175.23°±1.96°)显著大于我国运动员(156.37°±13.13°)。结论:我国跳台滑雪运动员起跳阶段起跳起始时刻应尽量降低身体重心以减少阻力,并适当提高膝关节角来提高出台后肢体伸展程度。起跳过程中提高膝关节蹬伸力量,同时适当降低髋关节伸展速度,避免风阻对躯干造成不利影响。室内及实地训练过程中,应在提升蹬伸爆发力的同时避免膝关节过度外翻,提高蹬伸力量及传递效率。 相似文献
18.
The long jump has been widely studied in recent years. Two models exist in the literature which define the relationship between selected variables that affect performance. Both models suggest that the critical phase of the long jump event is the touch-down to take-off phase, as it is in this phase that the necessary vertical velocity is generated. Many three dimensional studies of the long jump exist, but the only studies to have reported detailed data on this phase were two-dimensional in nature. In these, the poor relationships obtained between key variables and performance led to the suggestion that there may be some relevant information in data in the third dimension. The aims of this study were to conduct a three-dimensional analysis of the touch-down to take-off phase in the long jump and to explore the interrelationships between key variables. Fourteen male long jumpers were filmed using three-dimensional methods during the finals of the 1994 (n = 8) and 1995 (n = 6) UK National Championships. Various key variables for the long jump were used in a series of correlational and multiple regression analyses. The relationships between key variables when correlated directly one-to-one were generally poor. However, when analysed using a multiple regression approach, a series of variables was identified which supported the general principles outlined in the two models. These variables could be interpreted in terms of speed, technique and strength. We concluded that in the long jump, variables that are important to performance are interdependent and can only be identified by using appropriate statistical techniques. This has implications for a better understanding of the long jump event and it is likely that this finding can be generalized to other technical sports skills. 相似文献
19.
20.
张妮 《西安体育学院学报》2005,(Z1)
深入探讨远运动最佳腾起角的运动生物力学公式,分析了身体垂直速度、水平助跑速度利用率与最佳腾起角和跳远成绩的关系。以理论和大量技术数据为依据,指出起跳时身体垂直速度利用率对跳远成绩起着至关重要的作用。 相似文献