中国优秀男子短跑运动员途中跑垂直缓冲时段运动学参数的灰色关联度分析

通过对男子短跑运动员100m途中跑垂直缓冲时段运动学参数的灰色关联度分析，得出以下结论：下肢的关节点的夹角及上臂摆幅与跑速高度相关，各环节角度变化将影响短跑运动员跑进时的前蹬阻力及后蹬腿的蹬地方向，进而影响后蹬腿对地做功的有效功率。由此可见，增加短跑运动员途中跑垂直缓冲时段髋关节、膝关节及上臂前摆幅将有助于提高短跑的跑速。     

Ground reaction forces and knee kinetics during single and repeated badminton lunges

Repeated movement (RM) lunge that frequently executed in badminton might be used for footwear evaluation. This study examined the influence of single movement (SM) and RM lunges on the ground reaction forces (GRFs) and knee kinetics during the braking phase of a badminton lunge step. Thirteen male university badminton players performed left-forward lunges in both SM and RM sessions. Force platform and motion capturing system were used to measure GRFs and knee kinetics variables. Paired t-test was performed to determine any significant differences between SM and RM lunges regarding mean and coefficient of variation (CV) in each variable. The kinetics results indicated that compared to SM lunges, the RM lunges had shorter contact time and generated smaller maximum loading rate of impact force, peak knee anterior-posterior force, and peak knee sagittal moment but generated larger peak horizontal resultant forces (Ps < 0.05). Additionally, the RM lunges had lower CV for peak knee medial-lateral and vertical forces (Ps < 0.05). These results suggested that the RM testing protocols had a distinct loading response and adaptation pattern during lunge and that the RM protocol showed higher within-trial reliability, which may be beneficial for the knee joint loading evaluation under different interventions.     

排球、体操、短跑运动员在跳深动作中的生物力学特征比较

通过对优秀排球、体操、短跑运动员在不同高度下跳深动作中的运动学与动力学特征的测试.结果表明踏跳总时间、着台瞬刻的膝角、重心缓冲距、缓冲时间、蹬伸的幅度、重心腾起高度及垂直冲击力曲线带有明显的专业特色;最大缓冲膝角、最大蹬伸膝角及T蹬/T缓具有普遍性.选择不同跳深高度所产生的踏跳效果与不同专项及运动员自身承载能力密切相关.     

投篮时下肢发力的重要性及其生物力学分析

出手用力时的下肢发力是投篮过程中的一个重要环节，是投篮力量的主要来源之一。下肢适宜的发力是投篮时上肢协调、自然完成动作的保证，有利于手对球的控制，能够在一定程度上提高投篮命中率。本文将从生物力学角度，对投篮时下肢发力遵循的基本原理、发力动作的基本形式及其对投篮力量、出手速度、出手角度的影响进行论述。     

缓冲材料振动传递率的测试及非线性辨识

本文依据相关的标准和工程实际需求,分析了振动传递率测试中的试样固定方式,设计了一种简易固定装置。以发泡聚乙烯为例,分析了振动传递率测试方法,将4种厚度规格的试样分别在5种应力下进行了3Hz-200Hz的扫频试验,测出了发泡聚乙烯在不同厚度和应力下的振动传递率,并对试验结果进行了分析。采用BP神经网络建立了振动传递率非线性模型,并利用matlab／nntool对网络进行了训练和仿真,结果表明,该模型具有较强的泛化能力,能精确辨识振动传递率,从而可以预测任意厚度和应力下的振动传递率。