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1.
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2.
ABSTRACT

There are well-known biological differences between women and men, especially in technical-coordinative variations that contribute to sex differences in performance of complex movements like the most important offensive action in volleyball, the spike jump. The aim of this study was to investigate sex-dependent performance and biomechanical characteristics in the volleyball spike jump. Thirty female and male sub-elite volleyball players were analysed while striking a stationary ball with maximal spike jump height. Twelve MX13 Vicon cameras with a cluster marker set, two AMTI force plates, surface EMG, and a Full-Body 3D model in Visual3D were used. Main findings include sex differences (P< .05) in jump height (pη2 = .73), approach [speed (pη2 = .61), step length], transition strategy [plant angle, neuromuscular activation (pη2 = .91), horizontal force maxima and impulses], acceleration distances [centre of mass displacement (pη2 = .21), minimal knee and hip angles], use of torso and arms [incline, angular velocity (pη2 = .23)]. Correlations support that the results cannot be explained fully by strength and power differences between sexes but represent the product of technical-coordinative variations. Their relevance is acknowledged for both sexes and numerous performance determinants displayed sex differences. The integration of such attributes into sex-specific training seems promising but its effect requires further investigation.  相似文献   

3.
Repetitive stresses and movements on the shoulder in the volleyball spike expose this joint to overuse injuries, bringing athletes to a career threatening injury. Assuming that specific spike techniques play an important role in injury risk, we compared the kinematic of the traditional (TT) and the alternative (AT) techniques in 21 elite athletes, evaluating their safety with respect to performance. Glenohumeral joint was set as the centre of an imaginary sphere, intersected by the distal end of the humerus at different angles. Shoulder range of motion and angular velocities were calculated and compared to the joint limits. Ball speed and jump height were also assessed. Results indicated the trajectory of the humerus to be different for the TT, with maximal flexion of the shoulder reduced by 10 degrees, and horizontal abduction 15 degrees higher. No difference was found for external rotation angles, while axial rotation velocities were significantly higher in AT, with a 5% higher ball speed. Results suggest AT as a potential preventive solution to shoulder chronic pathologies, reducing shoulder flexion during spiking. The proposed method allows visualisation of risks associated with different overhead manoeuvres, by depicting humerus angles and velocities with respect to joint limits in the same 3D space.  相似文献   

4.

The objectives of this study were to describe the volleyball spiking actions used by players in top‐level competition, and also to examine the interrelationships between upper limb, lower limb and whole body kinematic variables, and post‐impact ball speed in the spiking technique. Two Photosonics Biomechanics 500 cine‐cameras operating at a nominal frame rate of 100 Hz were used to film the spiking actions of 10 male senior international volleyball players at the XVI Universiade (1991 World Student Games). Three‐dimensional object space co‐ordinates of digitized image co‐ordinates were obtained using a DLT algorithm and an array of calibration points in the filmed volume. Relationships between lower limb angular kinematics at take‐off, centre of mass vertical velocity at take‐off and centre of mass vertical displacement (jump height) were examined. Relationships between angular kinematics of the hitting arm and post‐impact ball speed were also determined. The mean (± S.E.) centre of mass vertical velocity at take‐off was 3.59 ± 0.05 m s‐1 and the mean height jumped was 0.62 ± 0.02 m. As expected, a significant correlation was found between the square of the centre of mass vertical velocity at take‐off and jump height (r = 0.78; P <0.01). No significant correlations were found between lower limb angular kinematics and centre of mass vertical velocity at take‐off or jump height. The mean post‐impact ball speed was 27.0 ± 0.9 m s‐1, and this was significantly correlated to maximum right humerus angular velocity (r=0.75; P< 0.01). Trunk rotation angular kinematics and right elbow angular velocity did not correlate significantly with post‐impact ball speed. It was also noted that the majority of players filmed did not fit into any of the spiking categories identified in earlier studies.  相似文献   

5.
ABSTRACT

This study was designated to investigate the kinematical differences between successful and faulty spikes, in order to identify the best strategies leading to better spike performance. Simulating a real-game condition, 13 elite youth attackers performed 6 spikes in the presence of 2 blocks. The kinematic variables of the spike performances were recorded using 6 optoelectronic cameras (Vicon Motion systems, Oxford, UK). The paired sample t-test was used to compare the kinematic variables recorded during the delivery of successful and faulty spikes. Among the successful trials, both the angular velocities of the knees (≈12.4%) and hips (≈13.3%), and the vertical velocity of the centre of mass at take-off (≈6.5%) and arm swing (≈8.2%) were considerably higher during the plant phase. Consequently, the jump (≈4.3%) and spike (≈1.5%) heights, as well as the wrist velocity (≈5.5%), were significantly higher during the jump phase of successful spikes. In successful spike performances, the attackers adopted higher hip and knee angular velocities, combined with efficient arm swings, to produce higher take-off velocities and reach higher jump heights. This approach provides them with the better position regarding the ball and the blockers to find the best path and hit the ball with higher arm velocities.  相似文献   

6.
Abstract

The aim of this study was to test the hypothesis that magnesium supplementation influences the physical performance of volleyball players, as the efficacy of this approach remains questionable. Twenty-five professional male volleyball players were assigned randomly to experimental (350 mg Mg · d–1, 4 weeks) and control groups (500 mg maltodextrin · d–1, 4 weeks) maintaining inter-group homogeneity of urinary magnesium. Erythrocyte, plasma and urinary magnesium levels, plasma creatine kinase activity, lactate production, maximal oxygen uptake (VO2 max) and plyometric (squat jump, countermovement jump, countermovement jump with arm swing) and isokinetic (peak torque, potency and total work) performances were evaluated before (T0) and after (T1) supplementation. Levels of erythrocyte and urinary magnesium and creatine kinase activity and VO2 max remained within normal ranges in both groups. Plasma magnesium decreased significantly only within the experimental group. Significant decreases in lactate production and significant increases (of up to 3 cm) in countermovement jump and countermovement jump with arm swing values were detected in the experimental group following magnesium supplementation, but not in the control group at T1. It is concluded that magnesium supplementation improved alactic anaerobic metabolism, even though the players were not magnesium-deficient.  相似文献   

7.
通过对沙滩、室内排球同一上步扣球起跳动作进行运动学、动力学同步数据采集，比较了二的力、冲量及功率等指标，得出如下结论：1)沙滩排球扣球起跳蹬伸阶段下肢肌群爆发力的发挥水平远远低于室内排球，不利于增大蹬伸冲量的积累；2)分析起跳冲量的内部结构发现。沙滩排球扣球起跳的蹬伸冲量远小于室内排球，从而致使沙滩起跳的恢复系数小于室内的；3)沙滩排球起跳的速度力量水平发挥远低于室内排球是在沙滩上起跳效果差的主要影响因素。  相似文献   

8.
The purpose of this study was to investigate the possible arm swing effect on the biomechanical parameters of vertical counter movement jump due to differences of the compliance of the take-off surface. Fifteen elite male beach-volleyball players (26.2 ± 5.9 years; 1.87 ± 0.05 m; 83.4 ± 6.0 kg; mean ± standard deviation, respectively) performed counter movement jumps on sand and on a rigid surface with and without an arm swing. Results showed significant (p < .05) surface effects on the jump height, the ankle joint angle at the lowest height of the body center of mass and the ankle angular velocity. Also, significant arm swing effects were found on jump height, maximum power output, temporal parameters, range of motion and angular velocity of the hip. These findings could be attributed to the instability of the sand, which resulted in reduced peak power output due to the differences of body configuration at the lowest body position and lower limb joints’ range of motion. The combined effect of the backward arm swing and the recoil of the sand that resulted in decreased resistance at ankle plantar flexion should be controlled at the preparation of selected jumping tasks in beach-volleyball.  相似文献   

9.
ABSTRACT

Knee joint coordination during jump landing in different directions is an important consideration for injury prevention. The aim of the current study was to investigate knee and hip kinematics on the non-dominant and dominant limbs during landing. A total of 19 female volleyball athletes performed single-leg jump-landing tests in four directions; forward (0°), diagonal (30° and 60°) and lateral (90°) directions. Kinematic and ground reaction force data were collected using a 10-camera Vicon system and an AMTI force plate. Knee and hip joint angles, and knee angular velocities were calculated using a lower extremity model in Visual3D. A two factor repeated measures ANOVA was performed to explore limb dominance and jump direction. Significant differences were seen between the jump directions for; angular velocity at initial contact (p < 0.001), angular velocity at peak vertical ground reaction force (p < 0.001), and knee flexion excursion (p = 0.016). Knee coordination was observed to be poorer in the early phase of velocity-angle plot during landing in lateral direction compared to forward and diagonal directions. The non-dominant limb seemed to have better coordination than the dominant limb during multi-direction jump landing. Therefore, dominant limbs appear to be at a higher injury risk than non-dominant limbs.  相似文献   

10.
We examined changes in the usage of muscular and motion-dependent moments during the long-term practice of a complex, multijoint movement. Seven participants practiced a cyclic movement of the upper limbs until their joint angular movements conformed to those of an expert. The motions of the participants were digitally recorded using four high-speed infrared cameras, and the joint kinematics and kinetics of the right arm were calculated. Practice brought about changes in the patterns of the net joint moment and in the contributions of the muscular and motion-dependent moments to the net moments. Practice also brought about a growing opposition between the directions of the two moments. These changes seemed to be important for improving the dynamic equilibrium of the movements.  相似文献   

11.
沙滩排球扣球起跳动作协调性特征的运动生物力学研究   总被引：4，自引：0，他引：4  
根据动作协调性理论并以室内排球为对照 ,采用理论分析与实验相结合的方法对沙滩排球扣球起跳阶段运动员的动作协调性进行了探讨。结果为 :沙滩排球扣球起跳阶段下肢髋 -膝 -踝运动链的运动基本上表现为同步性 ,而上肢 -躯干 -下肢运动链的运动则表现为顺序性 ;沙滩排球扣球起跳时肩关节发力过早影响了上、下肢动作的协调性 ;沙滩排球扣球起跳时人体两侧踝关节的非同步性导致了两侧自由下肢运动的非同步性 ,影响了扣球起跳的效果  相似文献   

12.
The purpose of this investigation was to detect whether differences exist concerning the dynamic and kinematic parameters of vertical squat jump (SJ) on rigid (RS) and sand (SS) surface. Fifteen elite male beach volleyball players (age: 25.6 +/- 6.2 years; height: 188.0 +/- 3.5 cm; body mass: 83.2 +/- 6.0 kg; mean +/- SD, respectively) performed SJ. Force platform and kinematic analyses were used with paired sample T-tests to evaluate the differences. Vertical jump height was significantly smaller (p < .001) on SS than RS. Maximal force and maximal power were significantly higher on RS than SS (p < .05 and p < .01 respectively). Impulse time was larger in SS but with no significant difference (p = .286). Kinematic analysis revealed significant differences between the values of ankle joint during starting posture (p < .01) and of hip joint at the moment of take-off (p < .05). Ankle joint range of motion and angular velocity was larger in SS (p < .05). In conclusion, SJ height on SS was smaller than on RS because of the compliance and the instability of the sand. This resulted in a reduction in maximum force and take-off velocity. Furthermore, the compliance of SS made it hard for the ankle to push along the vertical axis of the movement of the body and as a result it slipped behind in an attempt to maximize propulsion. As a result, the body tries to balance and equalise this movement and move the hip to larger extension.  相似文献   

13.
沙滩排球扣球起跳阶段人体环节运动的生物力学特征   总被引：4，自引：0，他引：4  
采用运动学手段对沙滩排球上步扣球起跳阶段人体环节的运动特征进行了研究，结果表明：“重心最低”时刻右踝角较小并没有影响人体的整体姿位；右踝角在缓冲阶段屈曲幅度较大，而在蹬伸阶段屈曲幅度较小；髋、膝二关节伸展过早，影响了下肢三关节蹬伸运动的连贯性；起跳时肩关节发力过早影响了上、下肢动作配合的协调性。  相似文献   

14.
The aim of this study was to examine the effect of opposition and gender on knee kinematics and ground reaction force during landing from a volleyball block jump. Six female and six male university volleyball players performed two landing tasks: (a) an unopposed and (b) an opposed volleyball block jump and landing. A 12-camera motion analysis system (120 Hz) was used to record knee kinematics, and a force platform (600 Hz) was used to record ground reaction force during landing. The results showed a significant effect for level of opposition in peak normalized ground reaction force (p = .04), knee flexion at ground contact (p = .003), maximum knee flexion (p = .001), and knee flexion range of motion (p = .003). There was a significant effect for gender in maximum knee flexion (p = .01), knee flexion range of motion (p = .001), maximum knee valgus angle (p = .001), and knee valgus range of motion (p = .001). The changes in landing biomechanics as a result of opposition suggest future research on landing mechanics should examine opposed exercises, because opposition may significantly alter neuromuscular responses.  相似文献   

15.
ABSTRACT

Biomechanical analysis has typically been confined to a laboratory setting. While attempts have been made to take laboratory testing into the field, this study was designed to assess whether augmented reality (AR) could be used to bring the field into the laboratory. This study aimed to measure knee load in volleyball players through a jump task incorporating AR while maintaining the perception-action couplings by replicating the visual features of a volleyball court. Twelve male volleyball athletes completed four tasks: drop landing, hop jump, spike jump, and spike jump while wearing AR smart glasses. Biomechanical variables included patellar tendon force, knee moment and kinematics of the ankle, knee, hip, pelvis and thorax. The drop landing showed differences in patellar tendon force and knee moment when compared to the other conditions. The hop jump did not present differences in kinetics when compared to the spike conditions, instead of displaying the greatest kinematic differences. As a measure of patellar tendon loading the AR condition showed a close approximation to the spike jump, with no differences present when comparing landing forces and mechanics. Thus, AR may be used in a clinical assessment to better replicate information from the competitive environment.  相似文献   

16.
Volleyball has been described as an 'interval' sport with both anaerobic and aerobic components. At the higher skill levels, technical performance may be limited by physical characteristics as well as physical fitness, and performance characteristics such as speed and vertical jump. This investigation compared teams at the two uppermost levels of men's volleyball in Canada for differences in physical, physiological and performance characteristics. The subjects were members of the national (n = 15) and universiade teams (n = 24). The parameters examined included percent body fat, maximal oxygen uptake (VO2 max), anaerobic power, bench press, 20-m sprint time and vertical jumping ability. The only significant difference in physical characteristics between the two teams was in age. Despite similarities in standing and reach height, the national team players had significantly higher block (3.27 vs 3.21 m) and spike (3.43 vs 3.39 m) jumps. An evaluation of anaerobic power measures produced similar power outputs during a modified Wingate test, yet the national team members had higher scores (P less than 0.05) for spike and block jump differences as well as 20-m sprint time. The large aerobic component of elite volleyball play was supported by the high VO2 max value recorded for the national team players (56.7 vs 50.3 ml kg-1 min-1). The results suggest that either years of specific physical conditioning and playing or the selection of individuals for the national team who possess more desirable characteristics as a consequence of genetic endowment, plays a significant role in the preparation of international calibre volleyball players.  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.
Knee injuries such as anterior cruciate ligament lesions and patellar tendonitis are very frequent in volleyball, and are often attributed to micro traumas that occur during the landing phase of airborne actions. The aim of the present study was to compare different jumping activities during official men's and women's volleyball games. Twelve top-level matches from the Italian men's and women's professional leagues were analysed. The jumps performed during the games were classified according to the landing technique used by the player (left or right foot or both feet together), court position, and ball trajectory. Chi-square analyses were performed to detect differences in landing techniques between the sexes, court positions, and trajectories when serving, attacking, blocking, and setting. Significant differences (P?相似文献   

19.
Understanding the technical requirements and underlying biomechanics of complex release and re-grasp skills on high bar allows coaches and scientists to develop safe and effective training programmes. The aim of this study was to examine the differences in the functional phases between the Tkatchev and Kovacs skills and to explain how the angular momentum demands are addressed. Images of 18 gymnasts performing 10 Tkatchevs and 8 Kovacs at the Olympic Games were recorded (50 Hz), digitised and reconstructed (3D Direct Linear Transformation). Orientation of the functional phase action, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical, along with shoulder and hip angular kinematics, angular momentum and key release parameters (body angle, mass centre velocity and angular momentum about the mass centre and bar) were compared between skills. Expected differences in the release parameters of angle, angular momentum and velocity were observed and the specific mechanical requirement of each skill were highlighted. Whilst there were no differences in joint kinematics, hip and shoulder functional phase were significantly earlier in the circle for the Tkatchev. These findings highlight the importance of the orientation of the functional phase in the preceding giant swing and provide coaches with further understanding of the critical timing in this key phase.  相似文献   

20.
Volleyball     
The purpose of this investigation was to detect whether differences exist concerning the dynamic and kinematic parameters of vertical squat jump (SJ) on rigid (RS) and sand (SS) surface. Fifteen elite male beach volleyball players (age: 25.6±6.2 years; height: 188.0±3.5cm; body mass: 83.2±6.0 kg; mean ±SD, respectively) performed SJ. Force platform and kinematic analyses were used with paired sample T‐tests to evaluate the differences. Vertical jump height was significantly smaller (p < .001) on SS than RS. Maximal force and maximal power were significantly higher on RS than SS (p < .05 and p < .01 respectively). Impulse time was larger in SS but with no significant difference (p = .286). Kinematic analysis revealed significant differences between the values of ankle joint during starting posture (p < .01) and of hip joint at the moment of take‐off (p < .05). Ankle joint range of motion and angular velocity was larger in SS (p < .05). In conclusion, SJ height on SS was smaller than on RS because of the compliance and the instability of the sand. This resulted in a reduction in maximum force and take‐off velocity. Furthermore, the compliance of SS made it hard for the ankle to push along the vertical axis of the movement of the body and as a result it slipped behind in an attempt to maximise propulsion. As a result, the body tries to balance and equalise this movement and move the hip to larger extension.  相似文献   

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