How does a baseball outfielder know where to run to catch a fly ball? The "outfielder problem" remains unresolved, and its solution would provide a window into the visual control of action. It may seem obvious that human action is based on an internal model of the physical world, such that the fielder predicts the landing point based on a mental model of the ball's trajectory (TP). However, two...

Plyometric training (PT) is a widely used method to improve muscles' ability to generate explosive power. Plyometric may improved skill performance of soccer players; however it is not clear. The aim of this study was to investigate the effect of PT on skill performance in soccer players. Twenty soccer players participated in this study as the subject. The subjects were randomly assigned to PT ...

The complexity of nearest-neighbor search dominates the asymptotic running time of many sampling-based motion-planning algorithms. However, collision detection is often considered to be the computational bottleneck in practice. Examining various asymptotically optimal planning algorithms, we characterize settings, which we call NNsensitive, in which the practical computational role of nearest-n...

Despite the fact that soccer is one of the most popular sports in the world, little attention has been paid to this game scientifically which could otherwise provide a broad range of interesting outcomes. Sport equipment has a significant effect on how a game is played. Different features of the soccer ball such as its size, structure, weight and potential incoming pressure also affect the natu...

Suppose that we sequentially place n balls into n boxes by putting each ball into a randomly chosen box. It is well known that when we are done, the fullest box has with high probability (1 + o(1)) lnn/ ln lnn balls in it. Suppose instead that for each ball we choose two boxes at random and place the ball into the one which is less full at the time of placement. We show that with high probabili...

The study aimed to prepare exercises specific the physical variables that (connecting inward medial side, opening outward lateral pulling right leg with a weight of -10 kg, left kg) and skill (control control ball, running ball between five figures, Shooting farthest distance) for players Musayyib Sports Club football aged (15-16) years, in which used (design two equal groups) test (pre-test po...

Background: The current study aimed to evaluate the effects of barefoot and shod running with two different styles on ground reaction force-frequency content in recreational runners with low arched feet. Methods: The statistical sample of this research was 13 males with PF (mean±SD age: 26.2±2.8 y; height: 176.1±8.4 cm; weight: 78.3±14.3 kg). A force plate (Bertec, USA) with a sample rate of 1...

The aim of the study was to examine how the training surface (i.e., clay or carpet) affects the characteristics (i.e., ball velocity, running pressure, running volume, and physiological responses) of a tennis training session. Ten competitive healthy and nationally ranked male tennis players (mean ± SD: age 24.2 ± 1.7 years, weight 81.4 ± 7.6 kg, height 1.88 ± 0.05 m, body mass index 23.1 ± 1.8...

The purpose of this study was to examine the differences in physical performance and game-specific skill demands between 5 positional groups in a professional rugby league team. Positional groups consisted of the backs (n = 8), forwards (n = 8), fullback (n = 7), hooker (n = 8), and service players (n = 8). Time-motion analysis was used to determine physical performance measures (exercise inten...