Hamid Reza Sadeghipour

Introduction: Knee joint is the most common site of injury in soccer players and muscles strength is known as one of the most important factors in the prevention of muscle and ligament injuries. The aim of this study was to investigate of the effect of the FIFA 11+ injury prevention program on knee isometric strength in youth male professional soccer players. Materials and Methods: Knee isometric strength of 24 professional soccer players in two experimental (12) and control (12) group were assessed by Biodex (version 3) in 30°, 60° and 90° knee flexion angle. For analysis of data, Paired sample t–test, Independent sample t-test, and two ways repeated measures ANOVA were used. Results: The results showed that quadriceps’ isometric strength in 90-degree was significantly higher in pre-test than post-test (P=0.004). Significant differences was observed in quadriceps’ peak torque in both control and experimental groups in 30-degree (P=0.000), 60-degree (P=0.01) and 90-degree knee flexions (P=0.004). In experimental group, significant differences between three knee flexion angles in quadriceps peak torque were observed (P=0.000), while maximum peak torque was found in 90-degree (303.6 N/m). Significant differences in hamstrings’ peak torque were found between three knee flexion angles of experimental group (P=0.000). Maximum torque produced by the hamstring muscles was observed in 30- degree knee flexion (155.1 N/m). Conclusion: It is concluded that the FIFA 11+ program is effective on young male professional soccer players. It is recommended that more exercises which aimed to increase hamstring strength such as hamstring curl add to the FIFA 11+ program.