Oliveira Nuno, Chiu Chuang-Yuan, Sanders Ross H
a Centre for Aquatics Research and Education, ISPEHS , The University of Edinburgh , Edinburgh , United Kingdom.
J Sports Sci. 2015;33(16):1675-81. doi: 10.1080/02640414.2014.1003590. Epub 2015 Jan 19.
The purpose of this study was to determine the kinematic patterns that maximized the vertical force produced during the water polo eggbeater kick. Twelve water polo players were tested executing the eggbeater kick with the trunk aligned vertically and with the upper limbs above water while trying to maintain as high a position as possible out of the water for nine eggbeater kick cycles. Lower limb joint angular kinematics, pitch angles and speed of the feet were calculated. The vertical force produced during the eggbeater kick cycle was calculated using inverse dynamics for the independent lower body segments and combined upper body segments, and a participant-specific second-degree regression equation for the weight and buoyancy contributions. Vertical force normalized to body weight was associated with hip flexion (average, r = 0.691; maximum, r = 0.791; range of motion, r = 0.710), hip abduction (maximum, r = 0.654), knee flexion (average, r = 0.716; minimum, r = 0.653) and knee flexion-extension angular velocity (r = 0.758). Effective orientation of the hips resulted in fast horizontal motion of the feet with positive pitch angles. Vertical motion of the feet was negatively associated with vertical force. A multiple regression model comprising the non-collinear variables of maximum hip abduction, hip flexion range of motion and knee flexion angular velocity accounted for 81% of the variance in normalized vertical force. For high performance in the water polo, eggbeater kick players should execute fast horizontal motion with the feet by having large abduction and flexion of the hips, and fast extension and flexion of the knees.
本研究的目的是确定在水球打蛋器式踢腿动作中使垂直力最大化的运动模式。对12名水球运动员进行测试，他们在躯干垂直且上肢露出水面的情况下执行打蛋器式踢腿，同时在九个打蛋器式踢腿周期中尽量保持高出水面的位置。计算下肢关节角运动学、脚的俯仰角和速度。使用独立下半身节段和组合上半身节段的逆动力学以及针对体重和浮力贡献的参与者特定二次回归方程，计算打蛋器式踢腿周期中产生的垂直力。归一化至体重的垂直力与髋关节屈曲（平均值，r = 0.691；最大值，r = 0.791；运动范围，r = 0.710）、髋关节外展（最大值，r = 0.654）、膝关节屈曲（平均值，r = 0.716；最小值，r = 0.653）以及膝关节屈伸角速度（r = 0.758）相关。髋关节的有效定向导致脚以正俯仰角进行快速水平运动。脚的垂直运动与垂直力呈负相关。一个包含最大髋关节外展、髋关节屈曲运动范围和膝关节屈曲角速度这些非共线变量的多元回归模型解释了归一化垂直力方差的81%。对于水球比赛中的高性能表现，打蛋器式踢腿运动员应通过大幅度外展和屈曲髋关节以及快速屈伸膝关节，使脚进行快速水平运动。
