篮球运动跳投训练浅析

运用理论分析的方法,阐述篮球运动中队员“跳投”的重要作用。通过三步系统化训练提高队员“跳投”的合理性及准确性,为大家提供参考。     

Evaluation of evidence-based medicine search skills in the clinical years

The librarians of the Health Sciences Library worked with the director of the Primary Care Clerkship to reinforce the principles of Evidence-Based Medicine (EBM) searching, taught during the first two years of medical school, through an intensive workshop. The purpose of the program was to ensure that students apply EBM principles in a timely and effective manner in clinical situations. Working in teams led by a resident and librarian, students researched real cases and then evaluated the effectiveness of their approach to the problems. This paper outlines the rationale for the team approach, reviews the administration of a computer-based workshop, and discusses the evaluation process. Evaluation focused on both the current workshop and its implications for the informatics program presented to students during years one and two.     

Gender differences among sagittal plane knee kinematic and ground reaction force characteristics during a rapid sprint and cut maneuver

Women are more prone to anterior cruciate ligament (ACL) injury during cutting sports than men. The purpose of this study was to examine knee kinematic and ground reaction forces (GRF) differences between genders during cutting. Male and female athletes performed cutting trials while force platform and video data were recorded (180 Hz). Differences (p < . 05) were observed between groups for knee flexion at contact and GRF at maximum knee flexion. Women averaged 5.8 degrees less flexion at contact and 1.0 N. (kg x m x s(-1))(-1) greater GRF at maximum flexion. Knee range of motion and peak GRF variables were not significantly different, but women had greater values. Women exhibited technique characteristics believed to increase ACL injury risk, but men exhibiting similar characteristics were also observed and could also be at risk.     

Optimizing segmental movement in the jumping header in soccer

This study looks at segmental movements in the jumping header from an optimization viewpoint. Investigations on the header so far have focused on head restriction in the movement but have not clarified how and to what extent body segments influence the performance of the skill. In the present study a biomechanical model was used to analyze the jumping header in simulated competition to give a clear picture of an optimized header. Skilled soccer players headed balls at speeds of 13 m x s(-1) the results indicated that the head moves as a free non-restricted segment in the jumping header and should be allowed to do so, even though much soccer literature says otherwise to prevent injuries. The arm movement showed individual characteristics and gave no general advantages in optimizing ball speed after impact in the header The movement of the legs was, on the other hand, the single most important factor in the skill. Therefore, coaches and players shouldfocus on developing muscle strength in the stomach, back and pelvis and should put no restrictions on head and arm movement to optimize the jumping header.     

The influence of moment of inertia on baseball/softball bat swing speed

The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent, the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets, balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured speeds, from 22 to 31 m s⁻¹, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest the importance of additional degrees of freedom in determining swing speed.     

对体育教师实施"能本管理"的研究

科学管理体育师资队伍,充分发挥每个体育教师的工作潜能,是全面提高学校素质教育质量的重要保证。从怎样培养体育教师的工作能力、激发体育教师工作的潜力及发挥好他们的聪明才智三方面论述了“能本管理”的概念、模式及对现实的重要意义。     

道家哲学思想对太极拳理论的影响

武术是中国的传统化,其中太极拳理论的形成是以道家哲学思想为基础,其拳理拳论、风格特点和价值取向,处处体现道家“依乎天理,顺其自然”的哲学思想和“虚静,守寂不争,为而不持”的精神境界及“贵柔守雌,柔弱胜刚强”的道家风度。道家哲学思想是太极拳哲理的理论基础。     

Price Indices for Artists – A Proposal

This paper proposes a price index for artists adjusted for the quality of the paintings, based on the ratio between the average market price and the average pre-sale estimate for paintings. We apply this methodology to a group of selected artists and schools presented in auctions worldwide in the period 1990–2001. A comparison with quality unadjusted and hedonic indices is also conducted.JEL Classification: C10, Z11