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Richard H. Cox Larry Noble Robert E. Johnson 《Research quarterly for exercise and sport》2013,84(2):101-107
Abstract Three initial step techniques for moving laterally are commonly used by middle blockers in volleyball. These three methods are (1) the slide step, (2) the cross-over step, and (3) the jab cross-over step. The purpose of the current investigation was to study the relationship between the three initial step techniques and selected time variables involved in the jumping and blocking action. Four criterion measures were extracted from film footage (100 frames/sec) using cinematographic data collection techniques. Six skilled volleyball players were used as subjects (3 men and 3 women). A split-split plot 3 (step method) × 2 (response direction) × 2 (sex) factorial design, with repeated measures on method and direction, were used to analyze the criterion measures. Results of the analysis revealed a clear relationship between step method and three of the time variables studied. Specifically, the cross-over steps (and in particular the jab cross-over) were observed to be superior to the slide step in terms of getting the athlete's body off the ground and into a blocking position quickly. While earlier investigations demonstrated that the slide step was superior in terms of getting from a middle blocking position to a floor switch mat (stationary target) it seems clear from the present investigation that the jab cross-over is superior in terms of actual jumping and blocking efficiency. 相似文献
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史东林 《河北体育学院学报》2015,29(3):68-71
目的:为了区别前手直拳与后手直拳下肢蹬地地面支撑反作用力的特征,进一步细化拳击下肢蹬地发力的特点.方法:运用两块KISTLER三维测力台和VICON MX红外高速摄影系统,让运动员分别以前手直拳和后手直拳全力击打固定目标,采集地面支撑反作用力参数,二者进行对比.结果:运动员后手直拳击打,双脚均主动发力,蹬地发力的时间均在100-200ms;发力50 ms时力值占最大力量峰值的百分比均低于35％,后续发力特征明显.前手直拳击打,前脚起主要作用,蹬地发力时间均在100ms之内,发力50 ms时力值占最大力量峰值的百分比均高于60％.与前手直拳相比,后手直拳下肢发力时长,具有显著性差异(P＜0.01).结论:拳击前手直拳与后手直拳下肢蹬地地面反作用力特征相比存在差异,从发力时长角度比较,前手直拳发力时间短,发力初期力量增长特征明显,表现为起动力量特征;后手直拳下肢蹬地后续发力特征明显,表现为爆发力属性特征. 相似文献
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