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1.
Abstract In research on the importance of the possession of the ball in soccer, little attention has been paid to its determinants. Using data from 170 matches of the 2003 – 2004 Spanish Soccer League, we explain why differences in the possession of the ball among teams are so great. In particular, four variables are examined: evolving match status (i.e. whether the team is winning, losing or drawing), venue (i.e. playing at home or away), and the identities of the team and the opponent in each match. Results of linear regression analysis show that these four variables are statistically significant and together explain most of the variance in possession. In short, home teams have more possession than away teams, teams have more possession when they are losing matches than when winning or drawing, and the identity of the opponent matters – the worse the opponent, the greater the possession of the ball. Combinations of these variables could be used to develop a model that predicts possession in soccer. 相似文献
2.
Determinants of possession of the ball in soccer 总被引:1,自引:0,他引:1
In research on the importance of the possession of the ball in soccer, little attention has been paid to its determinants. Using data from 170 matches of the 2003 - 2004 Spanish Soccer League, we explain why differences in the possession of the ball among teams are so great. In particular, four variables are examined: evolving match status (i.e. whether the team is winning, losing or drawing), venue (i.e. playing at home or away), and the identities of the team and the opponent in each match. Results of linear regression analysis show that these four variables are statistically significant and together explain most of the variance in possession. In short, home teams have more possession than away teams, teams have more possession when they are losing matches than when winning or drawing, and the identity of the opponent matters - the worse the opponent, the greater the possession of the ball. Combinations of these variables could be used to develop a model that predicts possession in soccer. 相似文献
3.
In this paper, an analytical and numerical study of the three-dimensional equations describing the motion through the air of a spinning ball is presented. The initial analysis involves constant drag coefficients, but is later extended to involve drag varying with the spin ratio. Excellent agreement is demonstrated between numerical, analytical and experimental results. The analytical solution shows explicitly how the ball’s motion depends on parameters such as ball roughness, velocity and atmospheric conditions. The importance of applying three-dimensional models, rather than two-dimensional approximations, is demonstrated. 相似文献
4.
Two different measurement techniques are used to examine the effect of surface geometry on soccer ball trajectories. Five
professional players are observed using high-speed video when taking curling free kicks with four different soccer balls.
The input conditions are measured and the average launch velocity and spin are found to be approximately 24 m/s and 106 rad/s.
It is found that the players can apply more spin (~50%) on average to one ball, which has a slightly rougher surface than
the other balls. The trajectories for the same four balls fired at various velocities and spin rates across a sports hall
using a bespoke firing device are captured using high-speed video cameras, and their drag and lift coefficients estimated.
Balls with more panels are found to experience a higher lift coefficient. The drag coefficient results show a large amount
of scatter, and it is difficult to distinguish between the balls. Using the results in a trajectory prediction programme it
is found that increasing the number of panels from 14 to 32 can significantly alter the final position of a 20 m-curling free
kick by up to 1 m. 相似文献
5.
Matteo Zago Marina Codari Massimo Grilli Giuseppe Bellistri Nicola Lovecchio 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(2):234-244
We explored the biomechanics of the 180° change-of-direction with the ball (half-turn) in soccer. We aimed at identifying movement strategies which enhance the players’ half-turning performance, by characterising technique kinematics and understanding the structure of biomechanical and anthropometrics variables. Ten Under-13 sub-elite male players were recorded with an optoelectronic motion analyser while performing a 5-m straight dribbling followed by a half-turn with the sole. Joints kinematics differences between faster and slower trials were found in support-side hip rotation, driving-side hip adduction, trunk flexion and rotation, and arms abduction. To unveil the data-set structure, a principal component (PC) analysis and a stepwise linear discriminant analysis were performed using 30 biomechanical parameters and four anthropometric variables for each trial. Seven retained PCs explained 79% of the overall variability, featuring combinations of original variables that help in understanding the factors facilitating fast half-turns: keeping short steps, minimising lateral and forward body movements, and centre-of-mass lowering, even with ample lower limbs ranges of motion (RoM); abducting the upper limbs while limiting trunk flexion and pelvic inclination RoM. Balance and task-constrained exercises may be proposed to improve this technique. Moreover, a quantitative knowledge of the movement structure could give coaches objective insights to better instruct young players. 相似文献
6.
This study involved a theoretical and an experimental investigation of the direct free kick in soccer. Our aim was to develop a mathematical model of the ball's flight incorporating aerodynamic lift and drag forces to explore this important 'set-play'. Trajectories derived from the model have been compared with those obtained from detailed video analysis of experimental kicks. Representative values for the drag and lift coefficients have been obtained, together with the implied orientation of the ball's spin axis in flight. The drag coefficient varied from 0.25 to 0.30 and the lift coefficient from 0.23 to 0.29. These values, used with a simple model of a defensive wall, have enabled free kicks to be simulated under realistic conditions, typical of match-play. The results reveal how carefully attackers must engineer the dynamics of a successful kick. For a central free kick some 18.3 m (20 yards) from goal with a conventional wall, and initial speed of 25 m·s?1, the ball's initial elevation must be constrained between 16.5° and 17.5° and the ball kicked with almost perfect sidespin. 相似文献
7.
Modelling the flight of a soccer ball in a direct free kick 总被引:2,自引:0,他引:2
This study involved a theoretical and an experimental investigation of the direct free kick in soccer. Our aim was to develop a mathematical model of the ball's flight incorporating aerodynamic lift and drag forces to explore this important 'set-play'. Trajectories derived from the model have been compared with those obtained from detailed video analysis of experimental kicks. Representative values for the drag and lift coefficients have been obtained, together with the implied orientation of the ball's spin axis in flight. The drag coefficient varied from 0.25 to 0.30 and the lift coefficient from 0.23 to 0.29. These values, used with a simple model of a defensive wall, have enabled free kicks to be simulated under realistic conditions, typical of match-play. The results reveal how carefully attackers must engineer the dynamics of a successful kick. For a central free kick some 18.3 m (20 yards) from goal with a conventional wall, and initial speed of 25 m x s(-1), the ball's initial elevation must be constrained between 16.5 degrees and 17.5 degrees and the ball kicked with almost perfect sidespin. 相似文献
8.
Takahito Iga Hiroyuki Nunome Shinya Sano Nahoko Sato Yasuo Ikegami 《Sports biomechanics / International Society of Biomechanics in Sports》2018,17(4):477-493
To assess ball impact force during soccer kicking is important to quantify from both performance and chronic injury prevention perspectives. We aimed to verify the appropriateness of previous models used to estimate ball impact force and to propose an improved model to better capture the time history of ball impact force. A soccer ball was fired directly onto a force platform (10 kHz) at five realistic kicking ball velocities and ball behaviour was captured by a high-speed camera (5,000 Hz). The time history of ball impact force was estimated using three existing models and two new models. A new mathematical model that took into account a rapid change in ball surface area and heterogeneous ball deformation showed a distinctive advantage to estimate the peak forces and its occurrence times and to reproduce time history of ball impact forces more precisely, thereby reinforcing the possible mechanics of ‘footballer’s ankle’. Ball impact time was also systematically shortened when ball velocity increases in contrast to practical understanding for producing faster ball velocity, however, the aspect of ball contact time must be considered carefully from practical point of view. 相似文献
9.
Alessandro H. Nicolai Ré Maria Teresa Cattuzzo Rafael dos Santos Henrique David F. Stodden 《Journal of sports sciences》2016,34(18):1716-1722
This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6–15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility. 相似文献
10.
In this study, we develop a finite element model to examine the oblique soccer ball bounce. A careful simulation of the interaction between the ball membrane and air pressure in the ball makes the model more realistic than analytical models, and helps us to conduct an accurate study on the effect of different parameters on a bouncing ball. This finite element model includes a surface-based fluid cavity to model the mechanical response between the ball carcass and the internal air of the ball. An experimental set-up was devised to study the bounce of the ball in game-relevant impact conditions. Ball speed, angle, and spin were measured before and after the bounce, as well as ball deformation and the forces during the impact. The finite element model has been validated with three different sets of data, and the results demonstrate that the finite element model reported here is a valuable tool for the study of ball bounce. After validation of the model, the effect of the friction coefficient on soccer ball bounce was studied numerically. Simulation results show that increasing the friction coefficient may result in reversal of the horizontal impact force. 相似文献
11.
Wind tunnel experiments were conducted, in particular focusing on slow unsteady variations of aerodynamic forces as a potential
cause of the knuckle effect of a new soccer ball (Teamgeist) under non-spinning condition. The experiments included simultaneous
measurements of the drag, the side force and the surface pressure on a ball surface, and the tuft visualisation to investigate
the flow field behind a ball. Of particular interest was the erratic nature of the knuckle effect resulting from the unsteady
movement of vortical wake structure in the supercritical Reynolds number regime. A simple 2-D numerical simulation of the
ball flight trajectory was performed by taking into account the unsteady side force data measured in the present experiments. 相似文献
12.
Philip E. Riches 《Sports Engineering》2006,9(1):39-47
This study develops a dynamic model of head acceleration, which incorporates physiologically related neck muscle contributions,
to further the understanding of the mechanical behaviour of the head-neck system during soccer heading. An inverted pendulum
is combined with a linear visco-elastic element to model the head-neck system following a half-sine input force. Model parameter
values were varied to obtain agreement with previously published experimental data (Naunheimet al., 2003), and were subsequently compared to literature values. The model predicted the same mechanical angular kinematics as
observed experimentally both during and post impact. The greatest acceleration was in the anterior direction at the instant
the ball left the head, attributed to the elastic stiffness of the neck musculature. The head-neck stiffness and damping coefficients
determined from the model (350 N m rad-1 and 4 N m s rad-1, respectively) were similar to those reported elsewhere when subjects were asked to resist maximally. The model may be subsequently
used to investigate differences in technique and ability with respect to the salient model parameters to further our biomechanical
understanding of soccer heading. 相似文献
13.
John K. De Witt Richard N. Hinrichs 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):382-390
The purpose of this study was to determine whether joint velocities and segmental angular velocities are significantly correlated with ball velocity during an instep soccer kick. We developed a deterministic model that related ball velocity to kicking leg and pelvis motion from the initiation of downswing until impact. Three-dimensional videography was used to collect data from 16 experienced male soccer players (age = 24.8 ± 5.5 years; height = 1.80 ± 0.07 m; mass = 76.73 ± 8.31 kg) while kicking a stationary soccer ball into a goal 12 m away with their right foot with maximal effort. We found that impact velocities of the foot center of mass (CM), the impact velocity of the foot CM relative to the knee, peak velocity of the knee relative to the hip, and the peak angular thigh velocity were significantly correlated with ball velocity. These data suggest that linear and angular velocities at and prior to impact are critical to developing high ball velocity. Since events prior to impact are critical for kick success, coordination and summation of speeds throughout the kicking motion are important factors. Segmental coordination that occurs during a maximal effort kick is critical for completing a successful kick. 相似文献
14.
《European Journal of Sport Science》2013,13(8):799-805
AbstractAchieving a high ball velocity is important during soccer shooting, as it gives the goalkeeper less time to react, thus improving a player's chance of scoring. This study aimed to identify important technical aspects of kicking linked to the generation of ball velocity using regression analyses. Maximal instep kicks were obtained from 22 academy-level soccer players using a 10-camera motion capture system sampling at 500 Hz. Three-dimensional kinematics of the lower extremity segments were obtained. Regression analysis was used to identify the kinematic parameters associated with the development of ball velocity. A single biomechanical parameter; knee extension velocity of the kicking limb at ball contact Adjusted R2 = 0.39, p ≤ 0.01 was obtained as a significant predictor of ball-velocity. This study suggests that sagittal plane knee extension velocity is the strongest contributor to ball velocity and potentially overall kicking performance. It is conceivable therefore that players may benefit from exposure to coaching and strength techniques geared towards the improvement of knee extension angular velocity as highlighted in this study. 相似文献
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16.
Giuseppe Gibertini Donato Grassi Carlo Macchi Giuseppe De Bortoli 《Sports Engineering》2010,12(3):155-161
The present paper describes the activity carried out to investigate the aerodynamic effects of cycling shoes for time trial
competitions. This subject has not been widely studied but can be important for an accurate aerodynamic optimisation of a
time trial cyclist. The study was carried out by means of wind tunnel testing: an appropriate test setup and an appropriate
test procedure (based on “effective angle of attack approach”) were developed in order to produce realistic test conditions.
The developed testing procedure was applied to two different shoe models, differently fastened. Furthermore, an important
point was the investigation of the overshoe effect. The results showed that the power required to overcome the shoe’s drag
is almost a tenth of the total power and that differences between the shoes can affect the cyclist’s performance. 相似文献
17.
李磊 《体育成人教育学刊》2008,24(6)
20世纪90年代以来,我国足球产业化逐步展开,并得到了比较稳定的发展。但是在足球产业化的同时,暴露出足球精神严重缺失的问题,包括运动员体育精神的沦丧,裁判等工作人员公平公正精神的模糊与球迷缺乏健康向上、理智成熟的素养。我国足球精神的缺失主要由于功利主义思想泛滥和精神文明建设的松懈。 相似文献
18.
Badminton synthetic shuttlecocks are known to have significantly different aerodynamic behaviours compared to feathered shuttlecocks due to the difference in designs and use of materials. Given the fragility of avian feathers used for feathered shuttlecocks and the constantly increasing cost of purchase, the interest to assess the current synthetic shuttlecock design as a feasible alternative has re-emerged. The single-piece injection-moulded synthetic shuttlecock has been the mainstream design for the past 50 years; however, little evidence has supported that the design mimics the aerodynamics of feathered shuttlecocks. Recently, a two-part skirt design has emerged proclaiming to have surpassed its synthetic predecessor in regard to matching the aerodynamics of feathered shuttlecocks. In the current study, two different synthetic designs (injection-moulded vs two-part skirt) were benchmarked against a feathered shuttlecock. A wind tunnel test was conducted between 30 and 145 km/h. The drag coefficients of both synthetic shuttlecocks were similar to the feathered shuttlecock up to 105 km/h. Thereafter, the drag coefficient of the injection-moulded design dropped from 0.62 to 0.5 and showing no signs of levelling at speeds over 105 km/h, while the coefficient for two-part skirt design stabilised at approximately 0.55. It was concluded that the two-part skirt design better mimicked the aerodynamics of the feathered shuttlecock. 相似文献
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