Landing techniques in volleyball

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   

Estimation of body density based on hydrostatic weighing without head submersion in young Japanese adults

Abstract

The aim of this study was to evaluate the effect of a soccer-training season on the anthropometric and performance characteristics of elite youth soccer players.

Two groups (age: 14.4 years) participated in this study: 1) 24 soccer players training 8 to 10 hours per week and 2) 26 non-athletic boys used as controls. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery test level 1) and anaerobic (counter-movement-jump (CMJ), squat-jump (SqJ), five-jump-test (5JT), and speed (T5m, 10 m, 30 m)) performances were assessed twice during 8 months (T0: October; T1: May) of the competitive season.

Data showed significant differences in height and weight at T0 between the two groups (P < 0.05), while no difference in the percentage of body fat (%BF) was observed. However, the soccer players were significantly taller and had lower %BF than age-matched controls at T1.

Compared to the controls, the soccer players attained better results in the physical fitness test (P < 0.05) at T0 and T1 except in (T5m) sprinting speed. Hence, significant improvements (P < 0.05) in physical parameters were observed between T0 and T1 only in soccer players.

The results demonstrate that soccer-training season was able to provide maturation free improvement in anthropometric and performance characteristics in young soccer players during the training season.     

规则修改对排球运动发展影响的博弈论分析

排球规则修改的目的在于均衡攻防矛盾，使排球运动更具魅力。本文从博弈理论角度分析了规则修改对排球运动技、战术发展带来的巨大影响。并揭示出排球运动的发展规律。     

Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilatory threshold

Abstract

The aim of this study was to determine the variations in substrate utilization between men and women matched for ventilatory threshold (T _vent) during incremental arm cranking and leg cycling exercise at 70, 85, 100 and 115% of the mode-specific T _vent. Recreationally active men (n = 12) and women (n = 10) with similar values for percentage of peak oxygen consumption at T _vent participated in the study. Ventilatory equivalence, excess CO₂ and modified V-slope methods were used concurrently to determine T _vent. The participants performed 5 min of exercise at each of 70, 85, 100 and 115% T _vent during both arm cranking and leg cycling exercise. The females were tested during the early follicular phase for all trials. A two-way mixed-design analysis of variance was performed to test for differences between the sexes. When carbohydrate and fat oxidation were expressed relative to total fat-free mass, carbohydrate oxidation during arm cranking and leg cycling was significantly higher in men than women at each percentage of T _vent. In contrast, women showed significantly higher fat oxidation across intensities during both arm cranking and leg cycling. Our results suggest that when substrate utilization is expressed relative to total fat-free mass, women appear to maintain a higher rate of fat and lower rate of carbohydrate oxidation than men during both incremental arm cranking and leg cycling exercise relative to T _vent.     

单脚起跳技术在排球快攻中的运用

分析了排球单脚起跳技术的特点及其运动生理学原理，并对单脚起跳技术在排球快攻中的运用进行了论述。     

女子排球比赛中大力跳发球与飘球运用对比分析研究

通过对2004年和2008年两届奥运会上女排比赛中大力跳发球与飘球运用的对比分析,为女子排球比赛发球技术的运用提出参考性建议。     

优秀排球运动员比赛效能的评定

介绍运用效能评分法对排球运动员在比赛中进行技术评定的方法。此评定方法既简单易学、易用,又能比较客观地衡量每一个运动员在比赛中技术水平发挥的状况和比赛中的作用,为赛后进行总结和下一步的训练提供可靠的资料     

每球得分制给中国男排带来的契机

分析排球每球得分制给男排比赛带来的影响、变化以及形成的特点，指出中国男排与世界强队相比存在着体能、发球、一传、技战术等诸方面差距，论证其向世界高水平冲击的可能性，为我国男排再创辉煌提供理论依据。     

Relationship between three-dimensional kinematics of knee and trunk motion during shuttle run cutting

Abstract

Female athletes are considered to exhibit knee and trunk motion that is characteristic of anterior cruciate ligament (ACL) injury. The aim of this study was to examine the in vivo motion of the trunk and knee during a cutting manoeuvre and determine the relationship between them. All participants (10 male and 10 female college athletes) performed a shuttle run cutting task with the left limb. Trunk inclination (forward and lateral) and knee joint angles (flexion/extension, abduction/adduction, and internal/external tibial rotation) were calculated. Differences between the sexes and associations between knee motion and trunk inclination were examined. An increase in trunk forward inclination was strongly correlated with an increase in knee flexion angle and moderately correlated with a decrease in the excursion of internal tibial rotation. An increase in right trunk lateral inclination was moderately correlated with an increase in excursion of internal tibial rotation. The results also showed differences between the sexes in trunk forward inclination, lateral inclination, and knee flexion angle, but no such differences in knee abduction or internal tibial rotation. Trunk inclination is related to knee flexion and excursion of internal tibial rotation. Female athletes demonstrate a low trunk forward inclination and knee flexion angle, a posture that resembles that of ACL injury.     

从世界女排强队起伏沉沦看中国女排2008年奥运会的夺冠之路

选取巴西、俄罗斯、意大利和中国队为研究对象,对近20年来这4支世界女排强队起伏沉沦的分析,找出保持世界强队所应具有的技战术特点,为中国女排在2008年奥运会夺取冠军提供建议。     

对中国男排在2003年世界杯赛中得分情况的比较研究

通过对2003年男子排球世界杯赛中国队全部11场比赛得分情况进行分类统计，运用数据分析、对比等方法探讨了中国男排在一攻、防守反击、拦网及发球方面的得分能力与其他各队相比的优势与差距，以期为今后在大赛中取得好的成绩提供改进思路。     

论现代排球竞争中的团队精神——联系中国女排参加2001年世界女子排球大奖赛的实况分析

现代六人制排球 ,系属有价值的现实群体的运动项目。在现代科学训练和实战中 ,要取得比赛的胜利 ,它既要靠超绝的功底 ,又要靠群体的团队精神 ,本文就新组建的中国女排参加 2 0 0 1年世界女子排球大奖赛的实况 ,进行实战剖析。     

从’98世界男排锦标赛看中国男排的一攻战术及效果

采用文献资料、录像观察、数理统计等研究方法,对中国男排参加’９８世界男排锦标赛时的一攻战术及效果进行分析。结果发现：与世界强队相比,中国男排的快攻成功率呈高度显著性差异;强攻成功率和失误率差异不显著。     

浅谈克服排球运动员比赛中不良心态的训练方法

排球比赛中，不良的心理状态，能降低运动员的运动能力和运动效果，造成比赛失利。本文对比赛中经常出现的心理障碍作出分析，并对目前被广泛采用的心理训练方法进行了探讨。     

第10届世界杯男子排球赛中国队与前8名球队技术效果的同异反分析

通过对第10届世界杯男子排球赛中国队与前8名球队,各项进攻、拦网、防守反击的技术指标的统计,并转换成联系数中的同、异、反,进行了技术状况的定量分析,指出了中国男排与其他世界男排强队之间的差距,并据此提出了相应的建议.     

’96全国男排甲A锦标赛扣球技术状况分析

强攻在我国男排比赛中占有重要位置,但快攻、后排攻等在比赛中运用很少,且各队水平不一、质量不高.今后只有不断强化扣球训练,才能提高扣球的攻击性和减少扣球的失误率.     

我国优秀排球运动员年龄、身高、体重与克托莱指数十年来发展状况的研究

运用文献法和数理统计法,分析1996-2005年我国男、女排球联赛运动员在年龄、体重、身高、扣球高度、拦网高度和克托莱指数发展特征。结果表明女排运动员各项指标发展较为平衡,男排运动员在年龄、体重、克托莱指数发展呈现出在较低的水平上逐年下降,与世界强队的差距越来越大,对我国排球运动员选材、训练提供理论依据,为实现2008年的男排战略目标提出建议。     

排球教学中时空知觉,运动知觉的训练

随着排球运动的发展,人们都重视运用时空知觉,运动知觉的训练来提高排球技术水平。本人在总结教学实践和文献搜集的基础上,对时空知觉,运动知觉作些分析,以供同行参考。     

Overuse in volleyball training/practice: A review on shoulder and spine-related injuries

Abstract

Overuse injuries are predominant in sports involving the repetition of similar movements patterns, such as in volleyball or beach volleyball, and they may represent as much a problem as do acute injuries. This review discusses the prevalence of two of the most common overuse-related injuries in volleyball: shoulder and back/spine injuries. Risk factors and the aetiology of these injuries are illustrated in order to make possible to initiate preventive programme or post-injuries solutions. Data collected from literature showed a moderately higher injury rate for overuse shoulder injuries compared to the back/spine (19.0±11.2% and 16.8±9.7%, respectively). These data could be underestimated, and future epidemiological studies should consider overuse injuries separately from the others, with new methodological approaches. In addition to age, biomechanical and anatomical features of a volleyball technique utilised in game and the amount of hours played are considered as the main risk factors for overuse upper limb injuries, both for professional and recreational athletes. Together with post-injuries solutions, great importance has to be placed on preventive programmes, such as preventive rehabilitation, stretching, adequate warm up, strength-power exercises, etc. Furthermore, it is particularly suggested that coaches and players work together in order to develop new game/training techniques that minimise stresses and range of motion of the principal anatomical structures involved, while maintaining athletes performance.