Associate Professor Department of Mechanical Engineering, Lafayette College Easton , PA, USA.
J Sports Sci Med. 2008 Mar 1;7(1):114-24. eCollection 2008.
This paper discusses the role of knee positioning and range-of- motion on the closed-stance forehand tennis swing. The analyses of tennis swing mechanics were performed using a computer model comprised of a full-body model of a human and an inertial model of a racket. The model was driven by subject forehand swings (16 female college-level subjects) recorded with a high-speed digital motion analysis system. The study discovered that both initial knee positioning and range-of-motion were positively related to racket velocity and characteristic of more skilled players. The direct effects of knee positioning and range-of-motion on racket movement are minimal, however there are several indirect biomechanical effects on the forehand motion such as movement of the body mass center, work of the knee, hip and back joints, and the angular range-of-motion of the hips and torso. Some of these indirect effects were related to racket velocity and characteristic of more skilled players. Factors that influenced knee positioning and range-of-motion include years of playing, amount of coaching, and body style. Efforts to both increase and restrict the knee movements of the subjects resulted in substantially lower racket velocities (and other detrimental biomechanical effects) implying that there may be optimal knee positions and range-of-motion for a given subject. The most skilled subject exhibited a high degree of consistency of knee positioning and range-of-motion. This subject adjusted for varying ball height through modified initial knee positioning while maintaining fairly constant ranges-of-motion. Key pointsInitial knee positioning and range-of-motion were positively related to racket velocity and characteristic of more skilled players for the closed stance forehand motion.Knee positioning and range-of-motion had several indirect biomechanical effects on the forehand motion such as movement of the body mass center, work of the knee, hip and back joints, and the angular range-of-motion of the hips and torso.Efforts to both increase and restrict the knee movements resulted in substantially lower racket velocities implying that there may be optimal knee positions and range-of-motion for a given subject.The most skilled subject exhibited a high degree of consistency of knee positioning and range-of-motion. This subject adjusted for varying ball height through modified initial knee positioning while maintaining fairly constant ranges-of-motion.
本文讨论了膝关节位置和运动范围对封闭站位正手网球挥拍的作用。网球挥拍力学的分析是使用一个由人体的全身体模型和球拍的惯性模型组成的计算机模型进行的。模型由受试者的正手挥拍（16 名女性大学水平的受试者）驱动，这些挥拍记录在高速数字运动分析系统中。研究发现，初始膝关节位置和运动范围与球拍速度和更熟练运动员的特征呈正相关。然而，膝关节位置和运动范围对球拍运动的直接影响很小，但对正手运动有几个间接的生物力学影响，如身体质心的运动、膝关节、髋关节和背部关节的功以及髋关节和躯干的角运动范围。其中一些间接影响与球拍速度和更熟练运动员的特征有关。影响膝关节位置和运动范围的因素包括打球年限、教练人数和身体类型。努力增加和限制受试者的膝关节运动导致球拍速度大大降低（和其他不利的生物力学影响），这意味着对于给定的受试者可能存在最佳的膝关节位置和运动范围。最熟练的受试者表现出高度一致的膝关节位置和运动范围。该受试者通过修改初始膝关节位置来适应不同的球高，同时保持相当恒定的运动范围。要点封闭站位正手击球时，初始膝关节位置和运动范围与球拍速度和更熟练运动员的特征呈正相关。膝关节位置和运动范围对正手运动有几个间接的生物力学影响，如身体质心的运动、膝关节、髋关节和背部关节的功以及髋关节和躯干的角运动范围。努力增加和限制膝关节运动导致球拍速度大大降低，这意味着对于给定的受试者可能存在最佳的膝关节位置和运动范围。最熟练的受试者表现出高度一致的膝关节位置和运动范围。该受试者通过修改初始膝关节位置来适应不同的球高，同时保持相当恒定的运动范围。
