(47) ARE PHASES OF A COUNTERMOVEMENT JUMP IMPACTED AFTER PLAYING A SOCCER GAME?

Purpose: The purpose of this study was to assess CMJ metrics before and after a soccer scrimmage with Division II female soccer players. Methods: During the initial phase of the off-season (first 3 weeks) Seventeen healthy female soccer players (age = 19.06 ± 1.03 years, height 167.38 cm ± 5.54 cm, mass 64.87 kg ± 7.51 kg). Any lower extremity injuries resulted in exclusion from the study A wireless uniaxial dual force plate system sampling at 1,000 Hz was used to measure CMJ performance. Jumping performance was measuring through the eccentric (braking phase duration, eccentric braking impulse, eccentric peak velocity, eccentric peak force, eccentric mean force, eccentric mean power) and concentric phase (jump momentum, concentric impulse, concentric duration, concentric phase, concentric peak velocity, concentric peak force, concentric mean force, concentric peak power, concentric mean power) additionally, other (contraction time, vertical jump height, RSI-modified, ) variables were also assessed. Each participant performed three countermovement jumps and fifteen-thirty seconds of rest were allowed in-between attempts. The best pre and post jumps per athlete were included for analysis. A Paired Samples t-test was used to assess pre and post jumps after players participated in a 70-minute soccer scrimmage. An alpha of 0.05 was used for level of significance. Results: For the eccentric phase, only the braking phase duration was significant (p = 0.012), all other variables were non-significant (p = 0.373 – 0.938). For the concentric phase, significant differences were seen for jump momentum and propulsive phase (p = 0.012 – 0.036) no differences were observed for any other concentric variables (p = 0.232 – 0.859), no significant differences were observed for other (p = 0.108 - 0.236). Conclusions: The present findings observed a significant difference for the braking phase duration and jump moment and propulsive phase for the concentric portion of the jump. Practical Applications: While measurements from a CMJ typically focus on power and velocity metrics, an overall encompassing assessment (duration, power, velocity, force) throughout the eccentric and concentric phases of the jump can allow for greater comprehension. Future studies may want to assess CMJ performance (using a force plate) with other sports before and after a game. Acknowledgements: Funding for this project was provided through a grant from the Office of Research and Sponsored Programs at the University of Central Oklahoma.