The Effect of Pain on Muscle Performance of Knee Extension and Flexion in Elite Athletes

Objective: We compared the key indices of isokinetic tests for knee joint extension and flexion according to the presence or absence of pain in elite athletes with previous knee and thigh injuries. Design: Cross-sectional study. Methods: Thirty-three elite athletes who participated in this study were divided into groups with and without pain due to previous knee and thigh injuries. Each group underwent an isokinetic muscle strength test for knee joint extension and flexion. The main indices of the isokinetic test were compared between the pain and pain-free groups. Results: Regardingknee flexion and extension at 60°/s in elite athletes, there was a significant difference only in the maximum torque average/kg for knee extension between groups. No statistically significant differences were observed in any of the other variables. The comparison of the pain and non-pain groups at 240°/s also showed a significant difference in the maximum torque average/kg for knee extension, with no statistically significant difference in any other variables. Conclusions: In subjects with previous knee or thigh injuries and mild pain during strong isokinetic strength tests, the torque average/kg was affected; however, there was no effect on the other strength variables. Therefore, it is beneficial to consider this aspect and use it as a basis for testing and training elite athletes.