Effects of eccentric exercise on optimum length of the knee flexors and extensors during the preseason in professional soccer players
Computing, Health and Science
Exercise, Biomedical & Health Science/Centre for Exercise and Sports Science Research
Objective: To assess the effects of eccentric exercise on optimum lengths of the knee flexors and extensors during the preseason in professional soccer. Design: Twenty-eight athletes from a professional Spanish soccer team (Division II) were randomly assigned to an eccentric exercise intervention group (EG) or a control group (CG). Over the four-week period two athletes from the control group suffered RF injuries and two athletes were contracted by other clubs. After these exclusions, both groups (EG, n ¼ 13; and CG, n ¼ 11) performed regular soccer training during the four-week preseason period. Results: After the four weeks, the optimum lengths of the knee flexors were significantly (P < 0.05) increased by 2.3 in the CG and by 4.0 in the EG. The change in the EG was significantly (P < 0.05) greater than that of the CG. The optimum lengths of the knee extensors were significantly increased only in the EG by 6.5 . Peak torque levels and ratios of quadriceps to hamstring (Q/H ratios) were not significantly altered throughout the study for either group. Conclusion: Eccentric exercise can increase the optimum lengths of both the knee extensors and knee extensors flexors during the preseason in professional soccer.