Relationship Between Shoulder and Knee Muscles Isokinetic Strength and Musculoskeletal Injuries in Iranian National Judo Teams: A Prospective Cohort Study

Abstract

Purpose: Judo stands as one of the world's oldest sports. However, the frequency of injuries in judo is also high. Crucially, identifying risk factors is necessary to prevent injuries. Despite the functional importance of strength in judo, the relationship between isokinetic strength and sports injuries has been little studied. The objective of this study was to prospectively examine the correlation between isokinetic muscle strength in elite judokas and the frequency of injuries. Methods:The population of this cohort and prospective study included judokas of different age groups from the Iranian national teams in 2020. Fifty-three of these judokas voluntarily participated in the study. Before the camps, the isokinetic strength of the knee flexors and extensors as well as the internal and external rotators muscles of the shoulders were measured at speeds of 60 and 300 °/s, and the injuries to these judokas were also recorded for nine months using a logistic regression test. Results:The findings indicated a significant association between the ratio of the maximum isokinetic strength of the hamstring to quadriceps muscle and judoka injuries at a speed of 60 °/s. A significant relationship was also found between the ratio of the maximum isokinetic strength of the shoulder flexors and shoulder extensors in judoka injuries at a speed of 300 °/s. However, no significant relationship was found between the strength ratio of the external and internal rotators of the shoulder in injuries of judokas at 60 and 300 °/s (P>0.05). Conclusion:The ratio of isokinetic strength between the muscles in the lower and upper limbs can serve as a predictive indicator for injuries among judokas. Consequently, it is recommended to employ these tests to evaluate injury risk.