Comparison of eccentric phase parameter and curve of countermovement jumps across different sports : a cross-sectional study

The countermovement jump (CMJ) is a widely used for assessing neuromuscular performance in athletes across various sports. This study explored eccentric kinetics and kinematics in the CMJ and compared force, power, and velocity-time curves between basketball, judo, and weightlifting athletes. Twenty-seven male college elite athletes (nine from each sport: basketball, judo, and weightlifting) with over seven years of sport-specific training experience participated in this cross-sectional study. Participants performed both unloaded and loaded CMJ tests on dual-force platforms. Eccentric phase variables including impulse, peak and mean force, rate of force development, power, and velocity were extracted and analyzed. Force-time, power-time, and velocity-time curves were normalized to 500 samples and compared using statistical parametric mapping (SPM) with one-way ANOVA and T-tests. During unloaded CMJ, basketball players demonstrated significantly higher eccentric impulse, eccentric peak power, and eccentric peak velocity compared to weightlifters ( p ≤ 0.014). During loaded CMJ, basketball players exhibited significantly greater eccentric impulse, eccentric peak rate of force development, eccentric mean force, eccentric mean power, and eccentric peak velocity compared to judo athletes ( p ≤ 0.05). SPM analysis revealed significant differences in normalized force-time curves between basketball and weightlifting athletes at 60.0 vs. 66.2% ( p ≤ 0.04) during loaded CMJ, and in normalized velocity-time curves between weightlifting and judo athletes at 36.4 vs. 43.2% ( p ≤ 0.03). These findings reveal distinct sport-specific eccentric phase characteristics and temporal patterns of force, velocity, and power application in CMJ, providing valuable insights for designing sport-specific assessment and training protocols.