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1.
Abstract

In taekwondo, the stance position can potentially affect kick performance. The aim of this study was to analyse mechanical variables in the roundhouse kick in taekwondo according to three stance positions (0°, 45°, 90°). Nine experienced taekwondo athletes performed consecutive kicking trials in a random order according to these three relative positions of the feet on the ground. Measurements for the mechanical analysis were performed using two 3D force plates and an eight-camera motion capture system. The taekwondo athletes’ reaction and execution times were shorter when starting from the 0° and 45° stance positions than from the 90° position (P < 0.05). Moreover, the ground reaction force was negatively correlated with execution time and positively with velocity of thigh and shank. Our results suggest that the stance position affects the execution technique of taekwondo athletes’ kicks. It is suggested that athletes should not adopt the 90° stance position because it will not enable them to achieve the best performance in the roundhouse kick.  相似文献   

2.
The purpose of the study was to investigate the effect of different kicking modality, i.e., erratic-dynamic target (EDT) versus static target (ST) on the performance of the roundhouse kick in two groups of taekwondo athletes of different skill level. Three-dimensional analysis and surface electromyography (SEMG) analysis were performed on 12 (Group A: six sub-elite, Group B: six elite) athletes to investigate muscle co-activation pattern under two conditions, i.e., EDT versus ST. In the results, the muscle recruitment ratio of the agonistic muscles was higher for Group A, whereas Group B had higher recruitment ratio for antagonist muscles. Overall, the co-activation index (CI) of hip joints appeared higher in the extensors for Group A, whereas higher CI was observed in flexor muscles for Group B with comparatively higher CI during EDT condition than ST condition. Higher value of CI was observed in flexor muscles of the knee joints among Group A during EDT conditions, in contrast, higher CI in the extensor muscles was observed among Group B during ST conditions. In conclusion, the study confirmed that erratic-dynamic movements of target could change the movement coordination pattern to maintain the joint stability of participants.  相似文献   

3.
目的:检测太极拳蹬腿动作支撑腿和动作腿的协调活动,揭示中枢双重命令下的下肢运动控制的特征.方法:太极拳运动员和初学者各10人,分两组.记录太极蹬腿动作时下肢肌肌电图、双下肢关节的角运动、足底中心压力的移位.每次试验8 s完成,重复5次.统计处理后,做肌电、运动和平衡分析.鲒果:两组间支撑腿的EMG、关节活动和COP位移出现了在形态上和幅度上的差别,但是在动作腿多表现在幅度上的差别.运动员支撑腿的平均EMG都高于初学者,只有股直肌有显著差异;运动员膝和髋关节的平均最大运动角度小于初学者,踝关节的平均最大运动角度稍稍比初学者大,只有髋关节的平均最大运动角度较为显著.运动员动作腿的平均EMG只有股直肌和胫骨前肌显著地高于初学者,而臀中肌显著地低于初学者;所有关节的平均最大运动角度都是运动员的显著大于初学者.平均足底中心压力的侧方和前后方位移都是运动员的显著大于初学者.运动员动作腿的起始运动约250～350ms,滞后于支撑腿起始运动的延迟时间.结论:运动员和初学者都可以用踝-髋策略来调节单腿直立的姿势平衡,但是运动员能够启动一个根据任务需要的前馈控制技术,通过下肢肌的积极活动,预先形成一个对抗蹬腿反作用力干扰的姿势稳定.因此,训练太极拳可以获得这个前馈控制技术.持续降低重心时,初学者的蹬腿和支撑两任务间出现了相互冲突.  相似文献   

4.

Fast unloaded movements (i.e. striking, throwing and kicking) are typically performed in a proximo‐distal sequence, where initially high proximal segments accelerate while distal segments lag behind, after which proximal segments decelerate while distal segments accelerate. The aims of this study were to examine whether proximal segment deceleration is performed actively by antagonist muscles or is a passive consequence of distal segment movement, and whether distal segment acceleration is enhanced by proximal segment deceleration. Seventeen skilled taekwon‐do practitioners were filmed using a high‐speed camera while performing a high front kick. During kicking, EMG recordings were obtained from five major lower extremity muscles. Based on the kinematic data, inverse dynamics computations were performed yielding muscle moments and motion‐dependent moments. The results indicated that thigh deceleration was caused by motion‐dependent moments arising from lower leg motion and not by active deceleration. This was supported by the EMG recordings. Lower leg acceleration was caused partly by a knee extensor muscle moment and partly by a motion‐dependent moment arising from thigh angular velocity. Thus, lower leg acceleration was not enhanced by thigh deceleration. On the contrary, thigh deceleration, although not desirable, is unavoidable because of lower leg acceleration.  相似文献   

5.
Little is known of the performance characteristics of the shotokan karate mae-geri kick. The aim of this study was to compare the execution time, the lower limb kinetics and kinematics, and their respective repeatability in the mae-geri kick of karate athletes of two different standards. Seventeen adult black belt karate competitors (9 national and 8 international athletes) performed six kicks with their dominant lower limb on a striking surface, combining maximum force impact and velocity. Execution time of movement and lower limb kinematics were recorded with a high-speed camera. Maximum force at impact and the forces exerted on the ground were measured using three force plates. The duration of the kick was significantly shorter for international than for national standard athletes. However, no significant difference in the maximum impact force of the kick was observed between the two groups. In addition, significant kinematic differences were observed between the groups, with two angles of motion and one velocity peak occurring sooner in the kick movement for the international athletes, specifically for the knee joint. International athletes also performed the kick with a significantly higher repeatability for duration and kinematics, specifically during the pre-loading phase that precedes the attack phase. We conclude that the duration of the kick and repeatability of lower limb kinematics could be useful in selecting top-level karate athletes and monitoring their training status.  相似文献   

6.
2006年全国跆拳道锦标赛技术统计与分析   总被引：6，自引：0，他引：6  
通过全程录像回放统计,对2006年全国跆拳道锦标赛男、女运动员决赛、半决赛阶段的32场比赛分别依运动员各种类型的踢法、交手时间、交手次数和得分方式进行统计分析。结果表明,在各项基本技术运用中,横踢仍然是核心技术和比赛得分的主要手段,其使用率均占60%以上;后踢和勾踢虽然在比赛中的总比重相对较小,但是实际的得分效果也相当显著。较以往各重大比赛,前踢技术首次进入比赛3大基本实战技术之列。3局比赛中,运动员应根据对手的不同情况安排战术和体力分配。  相似文献   

7.
Abstract

Little is known of the performance characteristics of the shotokan karate mae-geri kick. The aim of this study was to compare the execution time, the lower limb kinetics and kinematics, and their respective repeatability in the mae-geri kick of karate athletes of two different standards. Seventeen adult black belt karate competitors (9 national and 8 international athletes) performed six kicks with their dominant lower limb on a striking surface, combining maximum force impact and velocity. Execution time of movement and lower limb kinematics were recorded with a high-speed camera. Maximum force at impact and the forces exerted on the ground were measured using three force plates. The duration of the kick was significantly shorter for international than for national standard athletes. However, no significant difference in the maximum impact force of the kick was observed between the two groups. In addition, significant kinematic differences were observed between the groups, with two angles of motion and one velocity peak occurring sooner in the kick movement for the international athletes, specifically for the knee joint. International athletes also performed the kick with a significantly higher repeatability for duration and kinematics, specifically during the pre-loading phase that precedes the attack phase. We conclude that theduration of the kick and repeatability of lower limb kinematics could be useful in selecting top-level karate athletes and monitoring their training status.  相似文献   

8.
The initial stance position (ISP) has been observed as a factor affecting the execution technique during taekwondo kicks. In the present study, authors aimed to analyse a roundhouse kick to the chest by measuring movement coordination and the variability of coordination and comparing this across the different ISP (0°, 45° and 90°). Eight experienced taekwondo athletes performed consecutive kicking trials in random order from every of the three relative positions. The execution was divided into three phases (stance, first swing and second swing phase). A motion capture system was used to measure athletes’ angular displacement of pelvis and thigh. A modified vector coding technique was used to quantify the coordination of the segments which contributed to the overall movement. The variability of this coordination (CV) for each ISP was also calculated. Comparative analysis showed that during the stance phase in the transverse plane, athletes coordinated movement of the trunk and thigh with a higher frequency of in-phase and lower frequency of exclusive thigh rotation in the 0° stance than the 90° stance position (P < 0.05). CV was also influenced by the different ISP. During the first swing and the majority of the second swing phase, predominant in-phase coordination of the pelvis and thigh was observed. Including exercises that require in-phase movement could not only help athletes to acquire coordination stability but also efficiency. The existence of a constraint such as ISP implies an increase of the variability when the athletes have to kick from ISP they are not used to adopt (i.e., 0° and 90° ISP) as an evidence of adaptability in the athletes’ execution technique.  相似文献   

9.
The simple auditory reaction time is one of the fastest reaction times and is thought to be rarely less than 100 ms. The current false start criterion in a sprint used by the International Association of Athletics Federations is based on this assumed auditory reaction time of 100 ms. However, there is evidence, both anecdotal and from reflex research, that simple auditory reaction times of less than 100 ms can be achieved. Reaction time in nine athletes performing sprint starts in four conditions was measured using starting blocks instrumented with piezoelectric force transducers in each footplate that were synchronized with the starting signal. Only three conditions were used to calculate reaction times. The pre-motor and pseudo-motor time for two athletes were also measured across 13 muscles using surface electromyography (EMG) synchronized with the rest of the system. Five of the athletes had mean reaction times of less than 100 ms in at least one condition and 20% of all starts in the first two conditions had a reaction time of less than 100 ms. The results demonstrate that the neuromuscular-physiological component of simple auditory reaction times can be under 85 ms and that EMG latencies can be under 60 ms.  相似文献   

10.
We investigated joint coordination differences between Taekwondo back kicks and jumping back kicks, and how jumping (in performing the latter) would alter engaging ground reaction forces (GRF) in executing kicking. Ten skilful athletes volunteered to perform both kinds of kicking within the shortest time for three successful trials. Three high-speed cameras and two force platforms were used for data collection, and the trial with the shortest execution time was selected for analysis. Movements were divided into the rotation and attack phases. With comparable execution time and maximum joint linear/angular speeds, back kicks and jumping back kicks differ mainly in larger GRF in the latter, and in greater target acceleration in the former probably because the support leg prevented athletes’ rebounding after impact. In addition, more prominent antiphase and in-phase coordination between the shoulder segment and knee joint, and elongated rotation phase were found in jumping back kicks. Larger GRF values in jumping back kicks were generated for jump take-off rather than for a more powerful attack. In back kicks although the support leg remained ground contact, greatly decreased GRF in the attack phase suggested that the support leg mainly served as a rotation axis.  相似文献   

11.
目的：跆拳道是一个以无氧代谢为主的混合型代谢类型的运动,本次实验主要研究间歇性65次连续横踢训练对提高业余跆拳道运动员横踢耐力的影响。方法：以温州医学院跆拳道队16名运动员作为研究对象,按训练年限、训练水平和性别分为实验组（n=8）和对照组（n=8）。实验组除正常的训练外,进行8周的每周三次,每次4组,每组4次的间歇性65次连续横踢训练,对照组运动员进行常规训练。结果：1、8周训练后,实验组运动员65次连续横踢速度从37.76s提高到35.18s,对照组运动员从37.09s提高到36.35s,两组都有统计学差异,但实验组进步更多。2、实验组运动员在65次连续横踢后的即刻血乳酸水平比实验前下降明显,但峰值血乳酸水平明显增高。结论：通过8周的间歇性65次连续横踢训练,可以提高业余跆拳道运动员糖酵解供能能力,使跆拳道运动员在比赛中的持续横踢能力得到加强。  相似文献   

12.
为探求优秀散打运动员的体重差异与鞭腿技术动作特征是否对击打速度产生影响。方法：运用VICON Nexus 3D运动捕捉系统,对小、中、大三个级别15名运动员运用鞭腿技术动作快速击打目标物时的运动轨迹进行采集。依据鞭打动作特点和下肢关节运动特征,将技术动作划分为四个时刻、三个时段,并对四个时刻下肢关节的角度以及三个时段的动作位移、时间、速度、角速度等运用VICON Polygon分析软件进行计算。结果表明：启动时段（P1）小级别运动员的躯干和支撑腿各关节运动幅度呈"上大下小"状态,大级别运动员呈"上小下大"状态;三个级别运动员作用腿下肢关节的运动方向相同,运动幅度却出现差异,小级别运动员启动时段的动作速度相对较快。击打时段（P2）三个级别运动员支撑腿的髋、踝关节回旋运动方向出现差异;作用腿下肢关节运动方向相同,中级别运动员膝关节屈曲角度相对较大、转动半径相对较小,击打时段的动作速度也相对较快。回收阶段（P3）三个级别运动员支撑腿髋关节屈伸、回旋运动方向出现差异;作用腿下肢关节运动方向相同,小级别运动员作用腿下肢关节转动半径相对较小,回收时段的动作速度也相对较快。不同级别运动员鞭腿技术动作特征对击打速度存在显著性差异,相同级别散打运动员减轻体重、改善下肢关节的运动方向和运动幅度,才是提高击打速度的重要途径。  相似文献   

13.
女子跆拳道运动员注意瞬脱现象的研究   总被引：1，自引：0，他引：1  
对女子跆拳道运动员与普通女大学生、高水平与一般水平女子跆拳道运动员之间注意瞬脱特征进行测试,结果显示,女子跆拳道运动员的注意瞬脱特征与普通女大学生相比较注意瞬脱持续时间短,注意瞬脱程度轻.表现出了注意瞬脱的群体差异;女子高水平跆拳道运动员较一般水平女子跆拳道运动员注意瞬脱持续时间短,注意瞬脱程度轻,表现出了运动级别差异.  相似文献   

14.
Reaction time and response time are considered important abilities and can potentially affect combat performance. This study investigated the effect of a specific fatigue protocol on reaction time, response time, performance time, and kick impact. Seven male athletes reported to the laboratory on two different days. During day one, athletes performed a specific progressive taekwondo test, and on day two, a protocol for determining reaction time, response time, performance time, and kick impact before and after a time to exhaustion test at an intensity level corresponding to the maximal kick frequency obtained during the specific progressive taekwondo test. Muscle activation from rectus femoris and kick impact of the preferred limb were assessed. No differences were observed for response time and performance time. However, kick impact decreased (43 ± 27 to 13 ± 10 g, p < 0.01) while reaction time increased (145 ± 51 to 223 ± 133 ms, p < 0.05). Moderate correlation was observed between kick impact and response time (r = 0.565; p < 0.01), and kick impact and performance time (r = 0.494; p < 0.05). Results indicate that coaches and athletes may use taekwondo training programmes on coordination-based exercises leading to improve response time and to reduce fatigue effects in order to improve technique effectiveness and enhance the possibilities of scoring in a competitive situation.  相似文献   

15.
采用ME6000表面肌电仪和SONY高速摄像机对沈阳体育学院9名优秀速度滑冰运动员在模拟滑道训练中进行同步分析。结果表明：速度滑冰运动员侧蹬腿与支撑腿表面肌电原始电压有显著差异,左右伸膝肌群（腓外、腓内）在滑行过程中放电高于其他肌群;左腿为侧蹬腿时,半腱肌在膝关节折叠成小角度时放电最为明显;双支撑阶段右腿屈伸肌群表面肌电标准化电压在膝关节角为110～120°时达到最大值,在膝关节角大于120°之后肌肉力量降低明显。  相似文献   

16.
Kinematic comparison of the preferred and non-preferred foot punt kick   总被引：1，自引：1，他引：0  
Kicking with the non-preferred leg is important in Australian Football and becoming important in the rugby codes. The aim of this study was to examine differences between preferred and non-preferred leg kicking in the drop punt kick. Seventeen elite Australian Football players performed kicks with the preferred and non-preferred leg. Optotrak Certus collected kinematic data of the kick leg and pelvis (200 Hz) from kick leg toe-off until ball contact. Foot speed, knee and shank angular velocity at ball contact, and pelvis range of motion were significantly larger for the preferred leg (P < 0.05). In contrast, hip and thigh angular velocity at ball contact and hip range of motion were significantly larger for the non-preferred leg. This indicates different movement patterns, with preferred-leg kicks making greater use of the pelvis, knee, and shank while non-preferred leg kicks rely relatively more on the hip and thigh (P < 0.05). Reasons for this difference might be due to locking degrees of freedom or sub-optimal sequencing in the non-preferred leg. The thigh-knee continuum identified by Ball ( 2008 ) was also evident in this study. Findings have implications for training non-preferred leg kicking for performance and injury prevention.  相似文献   

17.
文章运用文献资料、数理统计和图像解析的研究方法,对二级跳远运动员的运动学指标进行研究。结果表明：（1）二级运动员起跳时间平均值是0.130s,缓冲时间平均值为0.048s,蹬伸时间平均值0.082s。缓冲时间、蹬伸时间与整个起跳时间过长。这与二级运动员本身身体素质和技术动作的优劣存在很大关系;（2）二级运动员着板瞬间,摆动腿的摆动角速度平均值为451.72°/s,膝关节角度平均为87.14°上板速度为8.58m/s,与前人的研究有出入;（3）二级运动员速度利用率为76.30%,速度利用率明显低于优秀运动的速度利用率。腾起角平均为26.66°,明显高于优秀运动员的18°-25°;（4）在蹬伸阶段摆动角速度的最大值与腾起角和成绩明显正相关。  相似文献   

18.
通过全程录像回放统计,对2012年伦敦奥运会男子跆拳道运动员技术统计与分析依运动员各种类型的腿法和得分方式进行统计分析。结果表明,在各项基本技术运用中,横踢仍然是核心技术和比赛得分的主要手段,其使用率均占50％以上;后踢、旋风踢和后旋踢虽然在比赛中的总比重相对较小,但是实际的得分效果也相当显著,3局比赛中,运动员应根据对手的不同情况安排战术和体力分配。  相似文献   

19.
中国优秀男子跆拳道运动员体型特征研究   总被引：11，自引：0，他引：11  
本文对1997全国跆拳道锦标赛男子各级别前4名运动员(共30名)的体型进行测定研究，旨在了解运动员体型的现状、特点和某些规律性特征，为科学选材，合理选择级别，提出客观依据。结果如下：我国优秀男子跆拳道运动员的体型具有一定的规律性特征，即体型分布相对较为集中，其体型特征为：体型匀称，肌肉、骨骼较为发达，体脂％低，身材较高大，其体型3因子均值为2．12～4．41～3．18；随级别升高，体型由外胚叶性一中胚叶型向中胚叶型转变；与国内外其它项目比较，体型有自身特点：3因子均值不大，差值较小，体型匀称。  相似文献   

20.
ABSTRACT

A possible link between soccer-specific injuries, such as groin pain and the action of hip adductor muscles has been suggested. This study aimed to investigate neuromuscular activation of the adductor magnus (AM) and longus (AL) muscles during instep and side-foot soccer kicks. Eight university soccer players performed the two types of kick at 50%, 75% and 100% of the maximal ball speed. Surface electromyography (EMG) was recorded from the AM, AL, vastus lateralis (VL) and biceps femoris (BF) muscles of both kicking and supporting legs and the kicking motions were three-dimensionally captured. In the kicking leg, an increase in surface EMG with an increase in ball speed during instep kicking was noted in the AM muscle (p < 0.016), but not in AL, VL or BF muscles (p > 0.016). In the supporting leg, surface EMG of both AM and AL muscles was significantly increased with an increase in the ball speed before ball impact during both instep and side-foot kicks (p < 0.016). These results suggest that hip adductor muscles markedly contribute to either the kicking or supporting leg to emphasise the action of soccer kicks.  相似文献   

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