Improving vertical jump profiles through prescribed movement plans.Mayberry, John K.; Patterson, Bryce; Wagner, PhilJournal of Strength & Conditioning Research: Post Acceptance: September 11, 2017 doi: 10.1519/JSC.0000000000002248 Original Research: PDF Only Abstract Developing practical, reliable, and valid methods for monitoring athlete wellness and injury risk is an important goal for trainers, athletes, and coaches. Previous studies have shown that the countermovement vertical jump test (CMJ) is both a reliable and valid metric for evaluating an athlete's condition. This study examines the effectiveness of prescribed workouts on improving quality of movement during CMJ. The dataset consists of 2425 pairs of CMJ scans for high school, college, and professional athletes training at a privately owned facility. During each scan, a force plate recorded three ground reaction force (GRF) measurements known to impact CMJ performance: Eccentric Rate of Force Development (ERFD), Average Vertical Concentric Force (AVCF), and Concentric Vertical Impulse (CVI). After an initial scan, coaches either assigned the athlete a specific 1- or 2- strength movement plan (treatment group) or instructed the athlete to choose their own workouts (control group) before returning for a follow-up scan. A multivariate analysis of covariance (MANCOVA) revealed significant differences in changes to GRF measurements between athletes in the two groups after adjusting for the covariates gender, sport, time between scans, and rounds of workout completed. A Principal Component Analysis of GRF measurements further identified four primary groups of athlete needs and the results provide recommendations for effective workout plans targeting each group. In particular, split squats increase CVI and decrease ERFD/AVCF; deadlifts increase AVCF and decrease CVI; alternating squats/split squats increase ERFD/CVI and decrease AVCF; and alternating squats/deadlifts increase ERFD/AVCF and decrease CVI. Copyright (C) 2017 by the National Strength & Conditioning Association.