@article{article_1706180, title={Acute Effects of Concentric and Eccentric Exercise on Knee Extensor Flexibility: A Comparative Trial}, journal={Eurasian Research in Sport Science}, volume={10}, pages={1–17}, year={2025}, DOI={10.29228/ERISS.52}, author={Şanlı, Göktuğ and Tatar, Yaşar and Uzun, Selda and Ramazanoğlu, Nusret}, keywords={Quadriceps Esnekliği, Eklem Hareket Açıklığı, izokinetik egzersiz, Fasya}, abstract={Understanding the effects of various muscle contraction modalities on joint flexibility is essential for refining exercise protocols. The acute effects of contraction type on flexibility, which is one of the main variables in exercise programming, are not yet comprehensively understood. This study aimed to compare the acute effects of a single session of isokinetic concentric and eccentric knee extension exercise on the active and passive flexibility of the knee extensor muscles in healthy young men. Twenty-six participants (age: 23±1.4 years) were randomly assigned to an eccentric (n=13) or concentric (n=13) exercise group. Active and passive knee flexion range of motion (ROM) were assessed using a smartphone inclinometer before and immediately after an isokinetic exercise protocol (3 sets of 12 repetitions at 60 degrees/second). Active knee flexion ROM significantly decreased from pre-test (Mean = 130.10 degrees) to post-test (Mean = 128.07 degrees) across both groups (p = 0.044). This decrease was similar between the Eccentric and Concentric groups, with no significant group differences or interaction effects observed. For passive knee flexion ROM, no statistically significant changes from pre-to post-test were detected for either group, and the changes did not differ significantly between the groups, although a trend towards a greater reduction was noted in the eccentric group. In conclusion, a single acute session of maximal isokinetic knee extension exercise resulted in a significant decrease in active knee extensor flexibility, comparably between concentric and eccentric contractions. These results highlight the complex nature of the acute flexibility responses to maximal exertion.}, number={1}, publisher={Marmara Üniversitesi}