(60) COUNTERMOVEMENT JUMPS, DOES A COMPETITIVE GAME OF SOCCER IMPACT THEM?

Purpose: The purpose of this study was to assess CMJ metrics before and after a soccer scrimmage with Division II female soccer players. Methods: Fifteen healthy female soccer players (age = 19.20 ± 1.01 years, height 166.77 cm ± 5.62 cm, mass 63.60 kg ± 6.90 kg) volunteered to participate in this study. Any lower extremity injuries resulted in exclusion from the study. Each participant performed three countermovement jumps before and after participating in a seventy-minute scrimmage. For each CMJ, fifteen-thirty seconds of rest were allowed in between attempts. The best pre and post jumps per athlete were included for analysis. A wireless uniaxial dual force plate system sampling at 1,000 Hz was used to measure CMJ performance. Jumping performance measured the eccentric phase (braking phase duration, eccentric braking mean velocity, eccentric braking peak velocity, eccentric mean force, eccentric braking peak force) concentric phase (takeoff time, jump momentum, concentric phase duration, concentric propulsive peak velocity, concentric propulsive mean velocity, concentric propulsive mean force, concentric propulsive peak force, concentric propulsive mean power, concentric propulsive peak power) and other variables (vertical jump height, RSI-modified). A Paired Samples t-test was used to assess pre and post CMJ performance, and an alpha of 0.05 was used for level of significance. Results: For the eccentric phase, only the braking phase duration was significant (p = 0.021), all other variables were non-significant (p = 0.477 – 0.939). For the concentric phase, significant differences were seen for jump momentum peak velocity, takeoff velocity and propulsive phase (p = 0.001 – 0.045) no differences were observed for any other concentric variables (p = 0.094 – 0.792), significant differences were observed vertical jump height (p = 0.045), no differences were seen for RSI-modified (p = 0.091 ) for other variables (p = 0.108 - 0.236). Conclusions: The present findings observed a significant difference for the braking phase duration post-game, while jump momentum and propulsive phase duration, peak velocity, and takeoff were all significantly decreased post-match. Lastly, the vertical jump height was significantly lower post-match compared to pre. Practical Applications: Assessment of sport performance before and after a competitive game (scrimmage, full-game) can allow coaches and health care staff vital information, allowing for potential modification with programming or rest protocols if needed. While strength and conditioning workouts (throughout a full collegiate season), coupled with specific sport practice can provide positive physiological adaptations, within game and compounding volume from practices and strength training sessions could increase overall fatigue, and may decrease recovery capabilities. Future research may want to use portable force plates and assess athletes and teams across a competitive season. Assessment of athletic performance via CMJs could allow staff a better understanding of fatigue levels, and possible contributing factors to it. Acknowledgements: Funding for this project was provided through a grant from the Office of Research and Sponsored Programs at the University of Central Oklahoma.