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1.
The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to clarify the mechanical loading characteristics and the role of neuromuscular function in the triple jump. Seven national triple jumpers (4 males, 3 females) volunteered to perform 3-6 jumps. The mean best performances were 14.32 - 0.45 m and 11.90 - 0.28 m for males and females, respectively. The three longest triple jumps for each jumper were selected for final analysis. The mean contact times were 0.139 s (hop), 0.157 s (step) and 0.177 s (jump). The largest ground reaction forces were observed in the step (15.2 times body weight), while the highest peak pressures were recorded under the heel and forefoot. The plantar pressure of the lateral side of the forefoot was highly related to the length of the triple jump ( P ? 0.05-0.01). In addition, electromyograms of both legs suggested that mechanical loading places high demands on the neuromuscular system, as characterized by the high rate of activation in the pre-activity phase followed by high eccentric activity. Thus, the high activities of the gastrocnemius, vastus lateralis and hip extensor muscles seem to play an important role in preventing unnecessary yielding of the jumper during the braking phase.  相似文献   

2.
The two-handed dyno technique was studied in nine experienced climbers. According to textbooks, the preferred technique is to jump only as high as necessary and to grab the upper hold exactly at the dead point (highest position of the body centre of mass). Piezoelectric force transducers were connected to the right and left footholds and to the lower and upper handholds. From the forces, the vertical take-off velocity and the jump height were calculated. The results showed that in unsuccessful jumps, the vertical take-off velocity is too small. In successful jumps, however, the vertical take-off velocity is higher than required. In order to reach the same required minimal height, the successful jumper produced a higher force than the unsuccessful (including marginal fail) jumper did. The force produced by the feet was approximately 1.8 times higher than that of the hands. Unsuccessful jumps were significantly closer to the dead point than successful ones. The peak force at the fingers after touchdown at the upper hold ranged from 1.1 to 1.63 times body weight. Overshooting, i.e. jumping higher than required resulted in a smaller peak force and a greater chance of performing a successful jump. In successful jumps, the climber jumps higher than required and grabs the upper hold before and below the dead point. Furthermore, the closer to the dead point the climber grasps the upper hold, the higher is the peak reaction force at the fingers. The advice for the climber is to jump higher than necessary (at least 10 cm), and to grab the handhold before the dead point. This results in a high success rate and a minimal finger injury risk.  相似文献   

3.
现代三级跳远运动员的速度训练   总被引：3，自引：0，他引：3  
郭元奇 《体育学刊》2001,8(2):57-59
三级跳远技术由高跳型、平跳型已经发展成速度型。为了适应这种技术，应该重新认识现代三级跳远运动员的速度训练，它包括发展运动员跑的速度(跑的能力、绝对速度、助跑速度)、速度性力量和快速跳跃能力。  相似文献   

4.
ABSTRACT

Previous research suggests that landing mechanics may be affected by the mechanics of the preceding jump take-off. The purpose of the present study was to investigate whether jump take-off mechanics influence the subsequent landing mechanics. Female volleyball (n = 17) and ice hockey (n = 19) players performed maximal vertical jumps with forefoot and heel take-off strategies. During forefoot and heel jumps, participants were instructed to shift their weight to their forefoot or heel, respectively, and push through this portion of the foot throughout the jump. Jump mechanics were examined using 3D motion analysis, where lower extremity net joint moment (NJM) work, NJM, and segment angles were compared between forefoot and heel jumps using multivariate ANOVA. During jump take-off, participants performed more positive ankle plantar flexor and knee extensor NJM work in forefoot compared to heel jumps (P < 0.05). From initial foot contact to foot flat, participants performed more negative ankle plantar flexor and hip extensor NJM work during heel compared to forefoot jumps (P < 0.05). The present results demonstrate that using a heel take-off strategy results in a different distribution of lower extremity NJM work and NJM during landing compared to landings following forefoot jumps.  相似文献   

5.
中国与世界男子三级跳远运动员3项指标及技术特点分析   总被引：6，自引：0，他引：6  
采用文献资料调研、数理统计和对比分析等方法,对中、外优秀男子三级跳远运动员成绩接近率、身体形态、年龄特征及技术特点进行对比分析。结果表明,同世界1999—2002年度最好成绩相比,中国运动员成绩起伏不定;身体形态同世界优秀运动员具有明显差异,适合采用以“平跳速度型”为主的技术;中国运动员理想的三跳比例是33.5％:30％:36.5％。  相似文献   

6.
The goal of an offensive Rugby Union lineout is to throw the ball in a manner that allows your team to maintain possession. Typically, the player catching the ball jumps and is lifted upwards by two teammates, reaching above the opposing player who is competing for the ball also. Despite various beliefs regarding the importance of the jumper’s mass and attempted jump height, and lifters’ magnitude and point of force application, there is negligible published data on the topic. The squeeze technique is one lifting method commonly employed by New Zealand teams during lineout plays, whereby the jumper initiates the jump quickly and the lifters provide assistance only once the jumper reaches 20–30 cm. While this strategy may reduce cues to the opposition, it might also constrain the jumper and lifters. We developed a model to explore how changes in the jumper’s body mass and attempted jump height, and lifters’ magnitude and point of force application influence the time to reach peak catch height. The magnitude of the lift force impacted the time-to-reach peak catch height the most; followed by the jumper’s (attempted) jump height and body mass; and lastly, the point of lift force application.  相似文献   

7.
通过对第29届北京奥运会男子三级跳远前12名运动员的跳远成绩、踏板成绩及三跳成绩(单足跳、跨步跳、跳跃)进行探索研究,揭示运动员在比赛过程中成绩创造的变化规律。为今后运动员和教练员更好地掌握三级跳远运动训练和比赛的技术技巧提供科学依据。  相似文献   

8.
The main aim of this study was to examine the age- and sex-associated variation in neuromuscular capacities of young distance runners. A secondary aim was to compare the magnitude of sex differences in young athletes in the same sport compared with the general population. Twenty-seven male and 27 female distance runners were enrolled in the study, whose ages ranged from 8.0 to 15.1 years at initial visit. Twenty males and 16 females were followed at approximate annual intervals for 4 or 5 years. Seven neuromuscular capacities were measured: quadrant jump, figure 8 run, standing long jump, vertical jump, flexed arm hang, sit-and-reach and sit-up. Age- and sex-associated variation was analysed by two-way analysis of variance. There were significant main effects for age for quadrant jump, figure 8 run, long jump, vertical jump, sit-and-reach and sit-up. There were significant main effects for sex for figure 8 run, long jump, vertical jump, flexed arm hang and sit-and-reach. The interaction between age and sex was statistically significant for long jump and vertical jump. In general, differences in neuromuscular agility (figure 8 run, quadrant jump) and explosiveness-power (long jump, vertical jump) between the sexes were attenuated before 13 years of age in young distance runners. However, during the adolescent growth spurt, differences in agility and power between the sexes emerged as a result of a continued increase in males and a plateau in females. Differences between the sexes in upper body neuromuscular endurance (flexed arm hang) and sit-and-reach persisted throughout the age range. The magnitude of sex differences between the runners and the general population varied by age and neuromuscular capacity.  相似文献   

9.
The main aim of this study was to examine the age- and sex-associated variation in neuromuscular capacities of young distance runners. A secondary aim was to compare the magnitude of sex differences in young athletes in the same sport compared with the general population. Twenty-seven male and 27 female distance runners were enrolled in the study, whose ages ranged from 8.0 to 15.1 years at initial visit. Twenty males and 16 females were followed at approximate annual intervals for 4 or 5 years. Seven neuromuscular capacities were measured: quadrant jump, figure 8 run, standing long jump, vertical jump, flexed arm hang, sit-and-reach and sit-up. Age- and sex-associated variation was analysed by two-way analysis of variance. There were significant main effects for age for quadrant jump, figure 8 run, long jump, vertical jump, sit-and-reach and sit-up. There were significant main effects for sex for figure 8 run, long jump, vertical jump, flexed arm hang and sit-and-reach. The interaction between age and sex was statistically significant for long jump and vertical jump. In general, differences in neuromuscular agility (figure 8 run, quadrant jump) and explosiveness-power (long jump, vertical jump) between the sexes were attenuated before 13 years of age in young distance runners. However, during the adolescent growth spurt, differences in agility and power between the sexes emerged as a result of a continued increase in males and a plateau in females. Differences between the sexes in upper body neuromuscular endurance (flexed arm hang) and sit-and-reach persisted throughout the age range. The magnitude of sex differences between the runners and the general population varied by age and neuromuscular capacity.  相似文献   

10.
The purpose of this investigation was to compare valgus/varus knee angles during various jumps and lower body strength between males and females relative to body mass. Seventeen recreationally active females (age: 21.94 ± 2.59 years; height: 1.67 ± 0.05 m; mass: 64.42 ± 8.39 kg; percent body fat: 26.89 ± 6.26%; squat one-repetition maximum: 66.18 ± 19.47 kg; squat to body mass ratio: 1.03 ± 0.28) and 13 recreationally active males (age: 21.69 ± 1.65 years; height: 1.77 ± 0.07 m; mass: 72.39 ± 9.23 kg; percent body fat: 13.15 ± 5.18%; squat one-repetition maximum: 115.77 ± 30.40 kg; squat to body mass ratio: 1.59 ± 0.31) performed a one-repetition maximum in the squat and three of each of the following jumps: countermovement jump, 30 cm drop jump, 45 cm drop jump, and 60 cm drop jump. Knee angles were analysed using videography and body composition was analysed by dual-energy X-ray absorptiometry to allow for squat to body mass ratio and squat to fat free mass ratio to be calculated. Significant differences (P ≤ 0.05) were found between male and female one-repetition maximum, male and female squat to body mass ratio, and male and female squat to fat free mass ratio. Significant differences were found between male and female varus/valgus knee positions during maximum flexion of the right and left leg in the countermovement jump, drop jump from 30 cm, drop jump from 45 cm, and drop jump from 60 cm. Correlations between varus/valgus knee angles and squat to body mass ratio for all jumps displayed moderate, non-significant relationships (countermovement jump: r = 0.445; drop jump from 30 cm: r = 0.448; drop jump from 45 cm: r = 0.449; drop jump from 60 cm: r = 0.439). In conclusion, males and females have significantly different lower body strength and varus/valgus knee position when landing from jumps.  相似文献   

11.
北京奥运会女子三级跳远决赛运动员的竞技能力   总被引：1，自引：0，他引：1  
对第29届北京奥运会女子三级跳远决赛运动员的基本情况、前后3跳成绩、成功率、速度变化特征等进行研究。结果表明：32～33岁是女子三级跳远运动员展示最佳竞技能力的成熟期，及格赛成绩平均比值约为97．03％。决赛成绩均达到个人最好成绩的，平均比值约99．8％。第2、3跳是决赛阶段出现最佳成绩的关键跳次，第2跳成功率最高，达100％；其次是第1跳的成功率也达到75％；第3、4跳次的成功率相等。前3名运动员中有两人的助跑速度达到8．16m／s以上，后3跳的成功率有所降低。  相似文献   

12.
In this study, we examined the effects of a prior run-up on intermittent maximal vertical jump performance. Seven regionally ranked male volleyball players volunteered to participate in the study. They performed three randomized tests: (1) six repeated intermittent maximal jumps (jump condition), (2) six repeated intermittent run-ups (run-up condition), and (3) six repeated run-ups followed by maximal jumps (run-up plus jump condition). All performances were assessed and blood lactate concentration and heart rate were measured before and after each of the tests. Mean ( +/- ) jump performance (64.7 +/- 2.3 cm) increased significantly (P = 0.02) over the course of the jump condition and was significantly higher (P < 0.001) than for the run-up plus jump condition (58.0 +/- 3.2 cm), which tended to decrease with repetition. Blood lactate concentration was significantly higher in the run-up plus jump condition (3.73 +/- 0.24 mmol . l(-1)) than in the jump (2.61 +/- 0.26 mmol . l(-1), P = 0.02) and run-up (2.86 +/- 0.18 mmol . l(-1), P = 0.03) conditions. The increase in heart rate was significantly higher both in the run-up plus jump condition (33 +/- 6 beats . min(-1), P = 0.05) and run-up condition (33 +/- 4 beats . min(-1), P = 0.02) than in the jump condition (21 +/- 3 beats . min(-1)). The results indicate that the addition of run-ups probably impeded performance in the repetition of vertical jumps.  相似文献   

13.
Abstract

The aim of this study was to determine the influence of run-up speed on take-off technique in the long jump. Seventy-one jumps by an elite male long jumper were recorded in the sagittal plane by a high-speed video camera. A wide range of run-up speeds was obtained using direct intervention to set the length of the athlete's run-up. As the athlete's run-up speed increased, the jump distance and take-off speed increased, the leg angle at touchdown remained almost unchanged, and the take-off angle and take-off duration steadily decreased. The predictions of two previously published mathematical models of the long jump take-off are in reasonable agreement with the experimental data.  相似文献   

14.
Females, as compared with males, have a higher proportion of injuries in the foot region. However, the reason for this gender difference regarding foot injuries remains unclear. This study aimed to investigate gender differences associated with rearfoot, midfoot, and forefoot kinematics during running. Twelve healthy males and 12 females ran on a treadmill. The running speed was set to speed which changes from walking to running. Three-dimensional kinematics of rearfoot, midfoot, and forefoot were collected and compared between males and females. Furthermore, spatiotemporal parameters (speed, cadence, and step length) were measured. In the rearfoot angle, females showed a significantly greater peak value of plantarflexion and range of motion in the sagittal plane as compared with males (effect size (ES)?=?1.55 and ES?=?1.12, respectively). In the midfoot angle, females showed a significantly greater peak value of dorsiflexion and range of motion in the sagittal plane as compared with males (ES?=?1.49 and ES?=?1.71, respectively). The forefoot peak angles and ranges of motion were not significantly different between the genders in all three planes. A previous study suggested that a gender-related difference in excessive motions of the lower extremities during running has been suggested as a contributing factor to running injuries. Therefore, the present investigation may provide insight into the reason for the high incidence of foot injuries in females.  相似文献   

15.
重新审度“三级跳远的极值与各跳最佳组合”的研究方法   总被引：4，自引：0，他引：4  
王炳彝  李实 《体育科学》1993,13(4):83-86
本文根据三级跳远的技术和三跳相互间的约束特点,运用逐步回归方法建立了世界水平三级跳远成绩与三跳远度的非线性最佳数学模型,并得出不同水平的三跳最佳组合与最大远度的关系。同时,分析了各跳对三级跳远成绩的影响,为指导不同水平的三级跳远训练制定了控制模式。  相似文献   

16.
对第11届全国运动会田径比赛女子三级跳远决赛运动员的基本情况、6次试跳成绩、成功率、助跑速度变化特征等进行研究。结果表明:20～25岁是我国优秀女子三级跳远运动员表现最佳竞技能力的成熟期;及格赛成绩达到个人最佳成绩的97.03%;决赛成绩达到个人最好成绩的98.23%。前3跳是决赛阶段出现最佳成绩的关键,其中第2跳尤为突出。第2、6跳的成功率最高,达到了100%;其次是第3、5跳的成功率为87.5%。前3名运动员的助跑速度达到8.8m/s以上,助跑速度与节奏的变化影响着运动员的试跳成功率,也影响着运动员竞技能力的发挥与释放。  相似文献   

17.
The aim of this study was to examine the acute effects of prolonged static stretching (SS) on running economy. Ten male runners (VO2(peak) 60.1 +/- 7.3 ml x kg(-1) x min(-1)) performed 10 min of treadmill running at 70% VO2(peak) before and after SS and no stretching interventions. For the stretching intervention, each leg was stretched unilaterally for 40 s with each of eight different exercises and this was repeated three times. Respiratory gas exchange was measured throughout the running exercise with an automated gas analysis system. On a separate day, participants were tested for sit and reach range of motion, isometric strength and countermovement jump height before and after SS. The oxygen uptake, minute ventilation, energy expenditure, respiratory exchange ratio and heart rate responses to running were unaffected by the stretching intervention. This was despite a significant effect of SS on neuromuscular function (sit and reach range of motion, +2.7 +/- 0.6 cm; isometric strength, -5.6% +/- 3.4%; countermovement jump height -5.5% +/- 3.4%; all P < 0.05). The results suggest that prolonged SS does not influence running economy despite changes in neuromuscular function.  相似文献   

18.
In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad x s(-1) and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5+/-7.1 years (mean +/- s). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets x 10 repetitions at 70% body mass load). Strength was reduced for 4 days (P< 0.05) but no significant differences (P> 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6+/-1.1% vs 95.2+/-1.3% of pre-exercise values, P< 0.05) and drop jump (95.2+/-1.4%, P< 0.05) performance. Creatine kinase was elevated (P < 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.  相似文献   

19.
Abstract

Although vertical jumping is often incorporated into physical activity tests for both adults and children, normative data for children and adolescents are lacking in the literature. The objectives of this study were to provide normative data of jump height and predicted peak leg power for males and females aged 10.0–15.9 years. Altogether, 1845 children from 12 state primary and secondary schools in the East of England participated in the study. Each child performed two countermovement jumps, and jump height was calculated using a NewTest jump mat. The highest jump was used for analysis and in the calculation of predicted peak power. Jump height and predicted peak leg power were significantly higher for males than females from the age of 11 years. Jump height and peak power increased significantly year on year for males. For females, jump height and predicted peak leg power reached a plateau after age 12 and 13 years respectively. This study provides normative data that can be used as a tool to classify jumping performance in children aged 10–15 years.  相似文献   

20.
The aim of this study was to determine the effects of external loading on power output during a squat jump on a force platform in athletes specializing in strength and power events (6 elite weight-lifters and 16 volleyball players) and in 20 sedentary individuals. Instantaneous power was computed from time-force curves during vertical jumps with and without an external load (0, 5 or 10 kg worn in a special vest). The jumps were performed from a squat position, without lower limb counter-movement or an arm swing. Peak instantaneous power corresponded to the highest value of instantaneous power during jumping. Average power throughout the push phase of the jump was also calculated. A two-way analysis of variance showed significant interactions between the load and group effects for peak instantaneous power (P< 0.01) and average power (P< 0.001). Peak instantaneous power decreased significantly in sedentary individuals when moderate external loads were added. The peak instantaneous power at 0 kg was greater than that at 5 and 10 kg in the sedentary individuals. In contrast, peak instantaneous power was independent of load in the strength and power athletes. Mean power at 0 kg was significantly lower than at 5 kg in the athletes; at 0 kg it was significantly higher than at 10 kg in the sedentary males and at 5 and 10 kg in the sedentary females. In all groups, the force corresponding to peak instantaneous power increased and the velocity corresponding to peak instantaneous power decreased with external loading. The present results suggest that the effects of external loading on peak instantaneous power are not significant in strength and power athletes provided that the loads do not prevent peak velocity from being higher than the velocity that is optimal for maximal power output.  相似文献   

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