Effects Of Concentric To Different Velocities Eccentric Training On The Speed Force Of Knee Extension And Flexion Muscles In Football Plavers

As a new method to develop speed force, the effect of concentric combination different velocities training on knee extension and flexion muscles in semiprofessional soccer players is rare reported in China and abroad and just at the beginning of the research. It’s important to research the influence of concentric-to-different velocities training to develop muscles’speed force and the relationship between concentric-to-eccentric training and velocities. The research tries to combine the new training method with football and discusses how the new training method influences the speed force of knee extension and flexion muscles of football players. The purposes of the research are finding the best eccentric contraction velocities for improving the speed force of football players’knee extension and flexion muscles and providing theoretical basis and application reference for determining the rehabilitation strength training plan.30football players who are taught by the same coach from Grade2009, the Athletic Sports College of Beijing Sports University, are randomly divided into three groups:the concentric contraction combined slow eccentric training group (Group S), the concentric contraction combined fast eccentric training group (Group F) and the control group (Group C). Firstly, the two groups both concentric contracted quickly to end of the range of join motion, then immediately started eccentric contraction at a quick speed (Is) or a relatively slow speed (3s),7repetitions per time,5sets in total. The interval time between each session is3minutes. This training lasted for6weeks,3times per week. There were muscle strength tests of knee extension muscles, knee flexion muscles before and after the training, using BIODEX SYSTEM3.0isokinetic muscle strength test system. The indexes which were chosen including kinetic parameters such as these muscles’peak torque during concentric and eccentric contractions and the durations to reach peak torque, and some speed force ability indexes of the whole lower limb such as20m spring and shuttle run. The test results were carried on statistics processing compared the different effects on speed force of lower body from different eccentric contraction speed. The results of the experiment indicated 1) The concentric contraction combined slow eccentric training and the concentric contraction combined fast eccentric training both can effectively improve the maximum strength of knee extension and flexion muscles of football players. The effect of the maximum strength of knee flexion muscles of the concentric contraction combined fast eccentric training is better than the slow group.2) The concentric contraction combined slow eccentric training and the concentric contraction combined fast eccentric training both can effectively improve the speed force of knee extension muscles of football players, but the best speed load which is aiming at developing the knee flexion muscles’fast concentric strength is not clear.3) The concentric contraction combined slow eccentric training and the concentric contraction combined fast eccentric training both can effectively improve the performance of fast specialized training of football players.