Potentiation of Stretch Shortening Cycle of Hip Moment and Power Only predict Jump Performance Enhancement

Abstract

<h3>Research Objectives</h3> To investigate if lower-extremity joint specific potentiation of stretch shortening cycle (SSC) during the propulsive phase of jump test predicts jump height. <h3>Design</h3> Cross-sectional study. <h3>Setting</h3> University research laboratory. <h3>Participants</h3> Twenty-two young adults (12 females; mean age=25.75±3.03 years). <h3>Interventions</h3> Not applicable. <h3>Main Outcome Measures</h3> Participantsperformed three countermovement jump (CMJ) and static Jump (SJ) and bent their knees to the same flexion degree on two floor-embedded force platforms (AMTI). Using a 3-dimensional (3D) motion capture system (Vicon), jump height (JH) was measured using greater trochanters markers data of both lower extremities. Joint-based moment (Jmom) and power (Jpwr) of hip, knee, and ankle were calculated. Potentiation of SSC was calculated as CMJ/SJ ratios of JH, Jmom, and Jpwr for hip, knee, and ankle. The Vicon system contains 11 infrared cameras and two force platforms to synchronize kinetic and kinematic data. Linear regression models were used to examine if SSC potentiation predicts JH, controlling for knee joint angle and sex. <h3>Results</h3> JHPotentiation was 1.30±0.24. SSC Jmom potentiation was 1.33±0.40, 1.04±0.13, and 1.02±0.12 for hip, knee, and ankle, respectively. SSC Jpwr Potentiation was 1.39±0.53, 1.03±0.18, and 1.02±0.18 for hip, knee, and ankle, respectively. The regression models documented that SSC potentiation of hip Jpwr and Jmom predicted 77% and 87% of the variance in JH, respectively, after controlling for knee joint angle and sex. No other significant JH predictors were identified (p>0.05). <h3>Conclusions</h3> The findings show that hip Jmom and Jpwr SSC potentiation were associated with Jump test performance during the propulsive phase These findings provide an insight into understanding the mechanical function of the contribution of SSC potentiation of the lower extremities to jump tests performance. <h3>Author(s) Disclosures</h3> All authors declare no conflicts.