北京残奥会男子轮椅篮球赛各队战术运用的探讨

对北京残奥会男子轮椅篮球参赛各队战术应用特征进行统计分析,以探索轮椅篮球运动项目特征,把握世界轮椅篮球发展方向,为我国轮椅篮球运动发展提供帮助。     

Do field position and playing standard influence athlete performance in wheelchair basketball?

Improved understanding of mobility performance in wheelchair basketball is required to increase game performance. The aim of this study was to quantify the wheelchair-athlete activities of players in different field positions and of different playing standard during wheelchair basketball matches. From video analysis, absolute and relative duration and frequency of wheelchair movements and athlete control options were examined in 27 national standard and 29 international standard players during entire wheelchair basketball matches. Between-group factorial analysis of variances identified that national players drove more forward (42.6 ± 6.8 vs. 35.4 ± 3.7%; effect size Cohen’s d (ES) = 1.48) and started more often driving forward (33.9 ± 2.6 vs. 31.8 ± 2.8; ES = 0.77) during a match while the mean activity duration for a single driving forward activity was longer (4.3 ± 0.9 vs. 3.7 ± 0.6 s; ES = 0.75) than for international players. Furthermore, national players performed fewer rotational movements (21.8 ± 4.0 vs. 28.9 ± 7.8%; ES = –1.30) and started less often with the rotational movements (35.0 ± 3.6 vs. 40.5 ± 5.5; ES = –1.21) while the mean activity duration for a single rotation activity was shorter (2.1 ± 0.3 vs. 2.3 ± 0.3 s; ES = –0.67) than for international players. Differences in mobility performance among guard, forward and centre players were minimal. The results should help wheelchair basketball coaches specify wheelchair-handling training techniques and means to optimise wheelchair-athlete configurations.     

Quantification of maximal power output in well-trained cyclists

ABSTRACT

This study aimed to compare mechanical variables derived from torque-cadence and power-cadence profiles established from different cycle ergometer modes (isoinertial and isokinetic) and modelling procedures (second- and third-order polynomials), whilst employing a novel method to validate the theoretical maximal power output (P_max). Nineteen well-trained cyclists (n = 12 males) completed two experimental sessions comprising six, 6-s maximal isoinertial or isokinetic cycling sprints. Maximal pedal strokes were extracted to construct power–cadence relationships using second- and third-order polynomials. A 6-s sprint at the optimal cadence (F_opt) or optimal resistance (T_opt) was performed to assess construct validity of P_max. No differences were found in the mechanical parameters when derived from isokinetic (P_max = 1311 ± 415, F_opt = 118 ± 12) or isoinertial modes (P_max = 1320 ± 421, F_opt = 116 ± 19). However, R² improved (P < 0.02) when derived from isoinertial sprints. Third-order polynomial modelling improved goodness of fit values (Standard Error, adjusted R²), but derived similar mechanical parameters. Finally, peak power output during the optimised sprint did not significantly differ from the theoretical P_max in both cycling modes, thus providing construct validity. The most accurate P-C profile can be derived from isoinertial cycling sprints, modelled using third-order polynomial equations.     

Division,result and score margin alter the physical and technical performance of elite wheelchair tennis players

ABSTRACT

This study determined the physical and technical demands of elite wheelchair tennis (WT) match-play, how the demands differed between divisions (Men, Women, Quad) and the effect that set result and score margin had on these demands. Seventeen WT players were monitored during a singles competition. Physical measures of performance were analysed using an indoor tracking system and inertial measurement units. Technical measures of performance were examined using video analysis. Physical measures of performance differed by division (Men > Women > Quad) for most parameters. Rallies were longer during Men’s (P = 0.027) and Women’s (P = 0.004) matches compared to Quad’s and fewer shots were hit off 2 bounces in Men’s matches compared to Women’s and Quad’s (P ≤ 0.026). High-speed activity (HSA) increased during losing sets (P = 0.043). Most physical measures of performance increased by moderate to large effects during sets with a small score margin (≤3 games differential). Mean speed and HSA were similar during losing sets, regardless of margin, but decreased (large effects) when winning by a large margin. This study demonstrated the physical and technical demands that elite WT players need to be prepared for and how situational factors can influence these demands.     

轮椅竞速 4 × 100m接力最佳起动时机的分析

通过对国家男子轮椅竞速队4×100m接力运动员接力每棒最佳起动时机的分析,以获取接力队员独立的每棒距离速度时间变化及相应的起动时间,用数值积分法计算最佳的接棒起动距离时机并和实际接力训练中的接棒起动距离时机进行比较.认为国家男子轮椅竞速队接力训练中出发距离偏小,启动时机过晚;根据最佳起动距离时机范围作接力测试时,交接棒可在前接力区完成,接力成绩有所提高.提出国家男子轮椅竞速队接力训练中要延长起动距离时机;计算的最佳出发起动时机可作为接力技术训练中起动距离时机设置的参考.     

3种自行车功率计无氧功率测试结果的比较

采用 Monark 834,Monark 839E,SRM3种自行车功率计对8名优秀男子自行车运动员进行30s Wingate 元氧功率测试(WAT),对测试结果进行比较,分析3种功率计测定参数的异同与自行车实际运动方式的差异。结果表明:Monark834进行 Wingate 测试和自行车运动实践不尽相符。Monark 839E 可以比较精确的反映受试者的起动能力。Monark 834和 Monark839E 进行 WAT 测试时,其预定负荷受到一定的限制。SRM 测试指标的内容和精度较Monark834、Monark 839E要高。从模拟自行车运动实际状况来看,SRM 是更适合自行车运动员测试的专业工具。     

中国轮椅篮球运动发展状况的研究

本文采用文献资料、问卷调查、专家访谈和数理统计等方法,对我国轮椅篮球运动的发展状况进行了调查研究。结果表明,中国轮椅篮球运动隶属中国残疾人体育协会,轮椅篮球队伍比较稳定,运动员年龄跨度较大,以中度残疾者为主,训练年限普遍较短,教练员多属兼职且年龄较大,篮球执教经历丰富,但对轮椅篮球规律认识不深。目前我国轮椅篮球训练条件较差,参加比赛均采用赛前集训形式,且比赛机会较少。     

SRM功率自行车模拟场地原地起动训练的研究

目的：通过对SRM功率自行车使用不同档住无氧测试结果的比较，并与场地原地起动训练结果对比，对自行车运动员原地起动能力的实验室测试、评定方法进行探讨。方法：8名优秀男子短距离自行车运动员使用SRM功率自行车9～13档进行15s起动测试和场地166m原地起动训练，对测试结果进行比较、分析。结果：用SRM功率自行车在选择不同档住进行测试时，Pmax除了在9～10、10～11、11～12之间没有显著性差异之外，其余各档住之间都有显著性差异。SRM功率自行车11档测出的TPmax、TCmax、Cmax结果与场地测试结果之间无显著性差异。结论：1）运动员最大功率和总功率输出水平是运动能力的基础，专项最大功率的出现取决于环境阻力和选取与环境阻力相匹配的最佳传动比，阻力或频率的改变都会使人体输出功率改变。2）使用SRM功率自行车进行测试时，应根据运动员的训练水平不同，选取合适的档住，在实验室模拟场地原地起动166m训练，11档是最合适的。     

Experimental laboratory apparatus to analyze kinematics and 3D kinetics in rowing

In order to quantify internal forces and articular moments, by the inverse dynamics method, specially at lumbar level, an experimental laboratory apparatus to analyze kinematics and 3D kinetics of rowers was developed. It comprised a 3D motion analysis system, a Type C Concept II ergometer, three force-plates, six axes and two miniature mono-dimensional force transducers. The apparatus was designed for each hand, with two miniature transducers integrated into new steel handles to measure the force developed by each hand. Furthermore, the apparatus was also designed for each foot. Two force platforms were placed under two new foot stretchers to measure force and moment developed by each foot. The ergometer also has a sliding seat under which was placed a miniature force platform. A study of the rowing movement of a regional level competition rower demonstrated the relevance of the data. This study was concerned with the 3D kinetics parameters expressed in the medio-lateral, anterio-posterior and vertical axes. Some obtained data are novel or rarely associated together and enable a better understanding of the rower movement.     

Caution: The use of an electromagnetic device to measure trunk kinematics on rowing ergometers

The aim of the study was to determine the accuracy and variability of an electromagnetic device in measuring spinal kinematics on a traditional and replica rowing ergometer. Kinematic data collected from the 3-Space Fastrak^TM system using a Standard Concept II ergometer were compared with a replica ergometer that was in part, composed of non-ferrous materials (modified ergometer). The Fastrak's sensors were fixed to a wooden “spine” with known angles (as measured by an inclinometer). The mean inclinometer angle from four sensors (1 ± 0.2°) was significantly different than the mean angle recorded on the standard ergometer ( ? 5.4 ± 3.4°) (p = 0.007) whilst the angles recorded on the modified ergometer (1.4 ± 0.8°) were statistically equivalent to the inclinometer recordings (p = 0.660). These results indicate that the presence of ferrous material in a standard ergometer reduced the accuracy and increased the variability of data collected with the electromagnetic device. However, information collected on largely non-ferrous ergometers can provide coaches, biomechanists and clinicians with a quick and effective way to measure trunk kinematics during ergometer rowing.