Bilateral deficit in the countermovement jump and its associations with judo-specific performance

Abstract

This study aimed to describe the bilateral deficit (BLD) during the countermovement jump (CMJ) in judo athletes and determine the relationship between the BLD and judo-specific performance.Fourteen male judo athletes participated. The athletes performed tree specific judo tests: Maximal Sprint Speed Judo Test, Maximal Aerobic Speed Judo Test, Special Judo Fitness Test (SJFT), and double-and single-leg CMJ. The follow CMJ variables were used: jump height JH, mean -MPO and peak -PPO power output, peak force -PF, peak velocity -PV and impulse -IMP. The Pearson's or Spearman's test were used (p<0.05). The results show that the BLD is found in all CMJ parameters (27% in JH; 20% in MPO; 22% in PPO, 61% in PF, 41% in PV and 31% in IMP). Negative correlations between first set of SJFTTT (total throws) and BLD in PF (r=-0.60; p=0.022) and between the second set of SJFTTT and BLD in MPO (r=-0.74;p=0.002), PV (r=-0.59;p=0.025) and IMP (r=-0.55; p=0.040) were found. Also, negative correlations between SJFTTT and the BLD in all CMJ parameters (r=-0.53 to -0.85;p<0.05) were found. The BLD in most CMJ variables is negatively correlated (large to very large) to the SJFTTT. So, high BLD values are related to poor SJFTTT performance.

Jump Height and Hip Power Decrease During Cognitive Loading Regardless of Sex: Implications for Sport Performance Metrics

“…reactive strength index ¼ jump height ground contact time (2) Vertical stiffness (N•m 21 •BW 21 ) was calculated as the peak vertical ground force, normalized to body weight, and divided by the change in sacrum position displacement (i.e., lower extremity displacement) during the eccentric phase (equation 3) (23). The 2 force plate signals were summed together for the calculation of impulse.…”

“…The 2 force plate signals were summed together for the calculation of impulse. Impulse (Ns•BW 21 ) was calculated as the integral of the force-time curve during the concentric phase and normalized to body mass (equation 4) (22). Joint power (Watts•BW 21 •HT 21 ) was calculated as the joint moment, normalized to body mass and height, and multiplied by the joint angular velocity (equation 5) (18).…”

“…Impulse (Ns•BW 21 ) was calculated as the integral of the force-time curve during the concentric phase and normalized to body mass (equation 4) (22). Joint power (Watts•BW 21 •HT 21 ) was calculated as the joint moment, normalized to body mass and height, and multiplied by the joint angular velocity (equation 5) (18). Joint moments in the power equation were calculated with standard inverse dynamic procedures and resolved into the proximal coordinate system.…”

“…There was no significant sex by condition interaction (F 1,39 5 1.78, p 5 0.190) or main effect of sex (F 1,39 5 0.89, p 5 0.353, mean difference 5 0.39 Watts•BW21 •HT21 [21.22 to 0.45], d 5 0.29) for hip power. There was a main effect of condition where the single-task condition displayed greater hip power than the dualtask condition (F 1,39 5 5.42, p 5 0.025, mean difference 5 0.29 Watts•BW 21 •HT 21 [0.04-0.54], d 5 0.21; Table…”

“…Jump height, and its contributing neuromuscular components (e.g., rate of force development, power, reactive strength index, and impulse), is representative of an athlete's lower-body strength and explosive capabilities (5,26). Specific neuromuscular performance metrics such as power and impulse have demonstrated associations with change of direction capabilities (4,29) and sport-specific performance (21).…”