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In this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles. 相似文献
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Nicholas P. Linthorne James E. Cooper 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):175-185
This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (μ = 0.21–0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient of friction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected. 相似文献
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The aim of this study was to determine the influence of run-up speed on take-off technique in the long jump. Seventy-one jumps by an elite male long jumper were recorded in the sagittal plane by a high-speed video camera. A wide range of run-up speeds was obtained using direct intervention to set the length of the athlete's run-up. As the athlete's run-up speed increased, the jump distance and take-off speed increased, the leg angle at touchdown remained almost unchanged, and the take-off angle and take-off duration steadily decreased. The predictions of two previously published mathematical models of the long jump take-off are in reasonable agreement with the experimental data. 相似文献
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Nicholas P. Linthorne 《Sports Engineering》2013,16(2):61-70
This study used a mathematical model to examine the effects of the sled, the running surface, and the athlete on sprint time when towing a weighted sled. Simulations showed that ratio scaling is an appropriate method of normalising the weight of the sled for athletes of different body size. The relationship between sprint time and the weight of the sled was almost linear, as long as the sled was not excessively heavy. The athlete’s sprint time and rate of increase in sprint time were greater on running surfaces with a greater coefficient of friction, and on any given running surface an athlete with a greater power-to-weight ratio had a lower rate of increase in sprint time. The angle of the tow cord did not have a substantial effect on an athlete’s sprint time. This greater understanding should help coaches set the training intensity experienced by an athlete when performing a sled-towing exercise. 相似文献
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Nicholas P. Linthorne 《Journal of sports sciences》2013,31(5):359-372
The aim of the study was to assess the accuracy of a method of calculating the optimum release angle in the shot put. Using the proposed method, the optimum release angle that produces the greatest flight distance is calculated by combining the equation for the range of a projectile in free flight with the relations between release speed, release height and release angle for the athlete. The method was evaluated using measurements of five college shot-putters who performed maximum-effort throws over a wide range of release angles. When the athletes threw with high release angles, the shot was released from a greater height above the ground and with a lower release speed. For all five athletes, the calculated optimum release angle was in good agreement with the athlete’s preferred release angle. Each athlete had his own specific optimum release angle because of individual differences in the rate of decrease in release speed with increasing release angle. Simple models of shot-putting were developed to explain the relations between release speed, height and angle in terms of the anthropometric and strength characteristics of the athlete. 相似文献
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Linthorne NP Everett DJ 《Sports biomechanics / International Society of Biomechanics in Sports》2006,5(2):243-260
We investigated the release angle that maximizes the distance attained in a long soccer throw-in. One male soccer player performed maximum-effort throws using release angles of between 10 and 60 degrees, and the throws were analyzed using two-dimensional videography. The player's optimum release angle was calculated by substituting mathematical expressions for the measured relationships between release speed, release height and release angle into the equations for the flight of a spherical projectile. We found that the musculoskeletal structure of the player's body had a strong influence on the optimum release angle. When using low release angles the player released the ball with a greater release speed and, because the range of a projectile is strongly dependent on the release speed, this bias toward low release angles reduced the optimum release angle to about 30 degrees. Calculations showed that the distance of a throw may be increased by a few metres by launching the ball with a fast backspin, but the ball must be launched at a slightly lower release angle. 相似文献
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Nicholas P Linthorne Maurice S Guzman Lisa A Bridgett 《Journal of sports sciences》2013,31(7):703-712
In this study, we found that the optimum take-off angle for a long jumper may be predicted by combining the equation for the range of a projectile in free flight with the measured relations between take-off speed, take-off height and take-off angle for the athlete. The prediction method was evaluated using video measurements of three experienced male long jumpers who performed maximum-effort jumps over a wide range of take-off angles. To produce low take-off angles the athletes used a long and fast run-up, whereas higher take-off angles were produced using a progressively shorter and slower run-up. For all three athletes, the take-off speed decreased and the take-off height increased as the athlete jumped with a higher take-off angle. The calculated optimum take-off angles were in good agreement with the athletes' competition take-off angles. 相似文献
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Optimum release angle in the shot put 总被引：1，自引：0，他引：1
Linthorne NP 《Journal of sports sciences》2001,19(5):359-372
The aim of the study was to assess the accuracy of a method of calculating the optimum release angle in the shot put. Using the proposed method, the optimum release angle that produces the greatest flight distance is calculated by combining the equation for the range of a projectile in free flight with the relations between release speed, release height and release angle for the athlete. The method was evaluated using measurements of five college shot-putters who performed maximum-effort throws over a wide range of release angles. When the athletes threw with high release angles, the shot was released from a greater height above the ground and with a lower release speed. For all five athletes, the calculated optimum release angle was in good agreement with the athlete's preferred release angle. Each athlete had his own specific optimum release angle because of individual differences in the rate of decrease in release speed with increasing release angle. Simple models of shot-putting were developed to explain the relations between release speed, height and angle in terms of the anthropometric and strength characteristics of the athlete. 相似文献
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