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1.
对男子速滑运动员500m起跑姿势的研究 总被引：1，自引：0，他引：1
采用三维摄像DLT法,用3台松下M9000摄像机在比赛条件下分别从侧面和正面进行同步定点、定焦拍摄,完整记录了参加2004年世界杯哈尔滨站男子500m速滑比赛的中、美共9名运动员的起跑动作。旨在揭示站立式起跑姿势和三点式起跑姿势的各自特点,研究结果表明:站立式起跑预备姿势利于从静止状态转入快速起动蹬冰状态,其稳定性低于三点式起跑姿势,采用三点式起跑姿势的起动前冲力更大,便于运动员增大起动步长,但采用站立式起跑姿势有利于提高起动频率;起跑阶段采用站立式起跑姿势的滑行速度明显高于采用三点式起跑姿势的运动员。 相似文献
2.
本文利用运动力学、运动医学以及生靳解剖学原理对男子手枪慢射姿势的稳定性做了分析。通过对研究对象的讨论研究,得出提高射击姿势稳定性对于选手射击成绩起到至关重要的作用。提出了提高射击姿势稳定性应该从以下几方面着手：形成站立位高效稳定角,在击发辟间保持好人与枪的一致性;姿势取位要以使身体感到舒适为标准,利用量骼承重,用力协调减轻肌肉符合。 相似文献
3.
本文通过对我国多向飞碟射击运动员的右肘位置与射击姿势关系的研究,发现优秀运动员的右上臂外展角为85°—95°,并从理论上论述了它的合理性。 相似文献
4.
一、站立架式分析
站立的进攻、防守、反击技术主要是抱腿及其各种变化，所以自由跤的站立姿势既要有利于我方抱上对方的腿，又要不利于对方抱住我方的腿。目的是和对手搏斗时不吃亏。运动员因级别和身材高矮不同其姿势虽有所变化，但万变不离其宗，都要以身体重心稳定和移动灵活为原则，并要求攻守兼备。常见的站立姿势有三种。 相似文献
5.
一、前言射击运动是一项综合心理、生理、技术诸因素的竞技体育项目、其中技术动作是提高射击水平的主要因素之一。射击技术的关键决定于运动员在瞄准和击发的过程中平稳持枪的能力。持枪的稳定一方面取决于运动的心理因素,另一方面则取决于合理的瞄准姿势。所以从力学角度探讨射击姿态控制的合理性和理论上最佳姿势的研究对提高运动技术水平是很有意义的。国外文献有过对射击稳定性指标测试 相似文献
6.
射击运动是一种长时间的静力项目,这一项目要求运动员在技术水平,生理素质和心理素质三方面均达到相当程度。在训练和比赛中,运动员必须在相当长的时间保持同一姿势,有效地调控自己的心理状态,尤其是保持良好的情绪状态和注意警觉性,这要求运动员具备良好的心理素质,尤其是有着良好的个性心理品质。 当前,国内外射击界日益重视运动员的心理素 相似文献
7.
实占姿势是跆拳道(竞技跆拳道以下同)基本技术之一,是跆拳道一切攻防技能的基础,通过对跆拳道实战姿势兀种不同的站立门法进行分类对比,以指导今后的跆拳道的教学和训练。通过分析对比,表明不同的站立方法对跆拳道运动员在比赛中采用何种技、战术有直接影响。 相似文献
8.
一、开始姿势的技术分析现代自由跤比赛,站立的进攻、防守、反击技术主要是抱腿及其各种变化,所以自由跤的站立姿势既要有利于我方抱上对方的腿,又要不利于对方抱住我方的腿。目的是和对手搏斗时不吃亏。运动员因级别和身材高矮不同其姿势虽有所变化,但万变不离其宗,都要以身体重心稳定和移动灵活为原 相似文献
9.
在射击运动员训练中,教练员必须认识到,强调运动员的错误动作就会使他们偏离积极思维的轨道。可用不强调错误信息的办法来消除错误动作．那就是注意正确技术可以改正错误动作。赞扬正确的动作,忽视错误动作才是积极思维。这样要求教练员评价射击姿势、动作的方式、说话态度要作较大改变。为射手创造一个正确的、成功的气氛,其成绩就会呈现出继续向上的趋势。 相似文献
10.
浅析男子手枪慢射的稳与扣山东省射击队石振１选题依据正确、合理的射击姿势，是射击运动员能够获得好成绩的基础，而能否适时恰到好处地掌握好扣扳机一系列配合动作，是取得优异成绩的关键。射击中的稳定性是良好击发技术动作体现出来的一种“美”的状态，但必须要有正确... 相似文献
11.
《European Journal of Sport Science》2013,13(6):469-474
Abstract Objective: To evaluate the influence of hamstring extensibility on spinal and pelvic postures adopted by young paddlers in their kayaks. Methods: Sixty-eight young elite kayakers were recruited for the study (mean value 15.23, s=0.68 years). Thoracic and lumbar curvatures and pelvic position were evaluated with a Spinal Mouse system in standing position and in the boat (seated in the kayak with the paddle resting on their thighs, right entry position and left entry position). Hamstring muscle extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into two groups with regard to straight leg raise angle (Group A, PSLR < 80°, n=32, and group B, PSLR ≥ 80°, n=32). Results: Paddlers with lower extensibility presented higher thoracic and lumbar flexion and a more posterior pelvic tilt in the kayak in all three positions. However, no significant differences were found between the groups when standing. Conclusion: The results suggest that lower hamstring extensibility is related to increased spinal flexion and posterior pelvic tilt, which can overload the spine during paddling training. A systematic and intensive stretching programme to improve hamstring muscle extensibility should be incorporated into the training activities of paddlers. 相似文献
12.
AbstractIn 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
13.
This study examines the validity of the SenseWear Armband in different temperatures using the old (SenseWear v2.2) and newest version of the algorithm (SenseWear v5.2) against indirect calorimetry (IC). Thirty-nine male and female students (21.1 ± 1.41 years) completed an exercise trial in 19°C, 26°C and 33°C consisting of 5 min standing followed by alternating walking/running at 35% and 65% of their maximal oxygen uptake. The accuracy of the algorithms was evaluated by comparing estimated energy expenditure (EE) to IC using a mixed-model design. No difference was reported in EE between the different temperatures for IC. Both algorithms estimated EE significantly higher when exercising at high intensity in 33°C compared to 19°C. Compared to IC, SenseWear v2.2 accurately estimated EE during standing and light intensity exercise but underestimated EE when exercising in a hot environment and at high intensity. SenseWear v5.2 showed a difference when exercising at high intensity in thermoneutral and warm conditions. The new algorithm improved EE estimation in hot environments and at high intensity compared to the old version. However, given the inherent inaccuracy of the EE estimates of SenseWear, greater weight should be given to direct monitor outputs rather than the ability of a monitor to estimate EE precisely. 相似文献
14.
Jose Ignacio Priego Quesada Pedro Pérez-Soriano Angel Gabriel Lucas-Cuevas Rosario Salvador Palmer Rosa Mª Cibrián Ortiz de Anda 《Journal of sports sciences》2017,35(14):1459-1465
ABSTRACTThe aim of this study was to assess the influence of different bike positions on the perception of fatigue, pain and comfort. Twenty cyclists underwent three tests that involved cycling for 45 min at their individual 50% peak aerobic power output while adopting different positions on the bike. Participants performed the cycling tests adopting three positions defined by two parameters (knee flexion angle [20°, 30°, 40°] and trunk flexion angle [35°, 45°, 55°]) in random order. Angles were measured using a 2D motion analysis system during cycling and applying Fonda’s correction factor. Perceptions of comfort, fatigue and pain were reported before the end of each test. The combination of 40° knee flexion and 35° trunk flexion was perceived as the most uncomfortable position. Moreover, greater knee flexion had a negative effect on trunk comfort, accompanied by greater levels of fatigue and pain perception in the anterior part of the thigh and knee. In conclusion, cyclists perceived the most comfortable position to be when the saddle height was within the recommended knee angle (30° calculated from the offset position or 40 ± 4.0° of absolute value). Upright trunk was found to be the most comfortable position for recreational cyclists, where aerodynamics is not so important. Cyclists’ bike perceptions should be taken into account when it comes to choosing the most beneficial position, since this can play a role in injury prevention and enhance cycling performance. 相似文献
15.
Svein Ohm Linge 《Sports Engineering》2011,14(1):39-47
The purpose of this work was to develop a new 2D gymnast-high bar model with horizontal bar endpoint dynamics included. To
this end, a three-spring high bar model was extended with a five segment gymnast model followed by evaluation and sensitivity
analysis. Evaluation over more than a complete giant swing (420°) was favourable (bar position rms errors <0.017 m, center
of mass angular position rms error <11°). Single parameter perturbations (10%) caused little deterioration in model performance
(lower 180°of the giant swing-bar position rms errors <0.006 m, arms’ angle rms error <0.9°). Combinations of parameter perturbations
gave bar position rms errors <0.008 m and arms’ angle rms error <1.8°. Model performance was most sensitive to errors in high
bar stiffness values. 相似文献
16.
ABSTRACTSprint cycling performance depends upon the balance between muscle and drag forces. This study assessed the influence of upper body position on muscle forces and aerodynamics during seated sprint cycling. Thirteen competitive cyclists attended two sessions. The first session was used to determine handlebar positions to achieve pre-determined hip flexion angles (70–110° in 10° increments) using dynamic bicycle fitting. In the second session, full body kinematics and pedal forces were recorded throughout 2x6-s seated sprints at the pre-determined handlebar positions, and frontal plane images were used to determine the projected frontal area. Leg work, joint work, muscle forces and frontal area were compared at three upper body positions, being optimum (maximum leg work), optimal+10° and optimal-10° of hip flexion. Larger hip (p = 0.01–0.02) and reduced knee (p = 0.02–0.03) contribution to leg work were observed at the optimal+10° position without changes at the ankle joint (p = 0.39). No differences were observed in peak muscle forces across the three body positions (p = 0.06–0.48). Frontal area was reduced at optimum+10° of hip flexion when compared to optimum (p = 0.02) and optimum-10° (p < 0.01). These findings suggest that large changes in upper body position can influence aerodynamics and alter contributions from the knee and hip joints, without influencing peak muscle forces. 相似文献
17.
Cyclists regularly change from a seated to a standing position when the gradient increases during uphill cycling. The aim of this study was to analyse the physiological and biomechanical responses between seated and standing positions during distance-based uphill time trials in elite cyclists. Thirteen elite cyclists completed two testing sessions that included an incremental-specific cycling test on a cycle ergometer to determine VO2max and three distance-based uphill time trials in the field to determine physiological and biomechanical variables. The change from seated to standing position did not influence physiological variables. However, power output was increased by 12.6% in standing position when compared with seated position, whereas speed was similar between the two positions. That involved a significant increase in mechanical cost and tangential force (Ftang) on the pedal (+19% and +22.4%, respectively) and a decrease (?8%) in the pedalling cadence. Additionally, cyclists spent 22.4% of their time in the standing position during the climbing time trials. Our findings showed that cyclists alternated between seated and standing positions in order to maintain a constant speed by adjusting the balance between pedalling cadence and Ftang. 相似文献
18.
Martin Pühringer Gerda Strutzenberger Daniela Leitl Konrad Holzner Hermann Schwameder 《European Journal of Sport Science》2017,17(9):1212-1219
The aim of the study was to quantify the activation of arm and shoulder muscles during a static therapeutic climbing exercise and to investigate the possibility of altering the muscle activation through arm position (Jug, Undercling, Sidepull internal rotated, Sidepull external rotated), hand support (one-handed, double-handed) and wall inclination (0°, 12°). Electromyographic (EMG) activity of 14 healthy, climbing unexperienced males for the right m. biceps brachii (BB), m. serratus anterior (SA), m. upper, middle and lower trapezius (UT, MT, LT) showed mainly low to moderate EMG activation levels (BB: 4.1–40.1% maximum voluntary isometric contraction (MVIC), SA: 4.5–24.5% MVIC, UT: 1.3–28.0% MVIC, MT: 8.6–47.1% MVIC, LT: 3.8–47.3% MVIC). Significant differences occurred between the four arm positions for the UT and LT. The one-handed support revealed significant higher muscle activation than the double-handed support in every condition except for SA in Undercling arm position at 12° wall inclination. Increasing the wall inclination (from 0° to 12° overhang) led to a significant increase in muscle activation in nearly every exercise variation and muscle. These findings suggest that arm position, hand support and wall inclination are appropriate possibilities of altering muscle activation patterns in therapeutic climbing. 相似文献
19.
髌骨软化的机制与预防 总被引：2，自引：2，他引：0
黄耕培 《天津体育学院学报》1993,8(3):15-19
为预防髌骨软化症,作者运用X光调查法和肌电图记录法,对膝关节半蹲位“内扣”与“不内扣”时髌骨关节面及膝关节屈伸诸肌肌电位的变化进行了研究。论述了髌骨软化症系髌骨关节面压力降低,代谢障碍所致,建议内扣动作应予废除。膝关节半蹲位两脚分开与肩同宽,屈膝60°,小腿前倾15°,不仅有利于运动,而且亦是预防髌骨软化症的措施。 相似文献
20.
目的：研究青年人群、中年人群和老年人群在静态下不同体位颈总动脉血流最大流速的特征。方法：选取安庆师范大学165名志愿者,采用Philps Color Doppler CV850彩色超声,对18~25岁(不含25)、25~59岁(含59)以及59岁以上3个年龄段不同性别的人群在4种体位状态下颈总动脉血流最大流速进行测量。结果：右侧颈总动脉：性别相同时,青年男性组和中年男性组、青年女性组和老年女性组在直立位上具有非常显著性差异;中年男性组和老年男性组在仰卧位上具有非常显著性差异;青年女性组和中年女性组在头低位-30°上具有非常显著性差异。左侧颈总动脉：年龄相同时,中年男性组和中年女性组在仰卧位上具有非常显著性差异,中年男性组和中年女性组在头低位-90°上具有非常显著性差异;性别相同时,中年女性组和老年女性组在直立位上具有非常显著性差异;中年男性组和老年男性组在头低位-30°上具有非常显著性差异。结论：无论男女,随年龄的增大颈总动脉血流最大流速减慢;体位由仰卧位、直立位、头低位-30°、头低位-90°的顺序变化,颈总动脉血流最大流速减慢;同年龄段,颈总动脉血流最大流速男性均高于女性。 相似文献