BACKGROUND: A player’s performance in the National Football League (NFL) combine can greatly affect when they are drafted, and therefore can affect their contracts and signing bonuses. Vertical jump is one of six different non-position specific drills that prospective NFL players complete at the NFL combine and is highly associated with biomechanics and other performance measures. Therefore, this study aimed to determine the techniques that lead to a higher vertical jump. METHODS: Two researchers independently reviewed videos of 50 different players performing a vertical jump and came to a consensus on the following variables: whether the athletes rocked back on their heels prior to jump, where they landed with respect to their take-off, whether their feet came off the ground during the countermovement, if their knee flexed in the air, and if their knee flexed greater than 45 degrees while in the air. These factors were investigated using an Analysis of Variance (ANOVA) with an alpha level of 0.05. Each factor was treated as an independent variable in a separate one-way ANOVA, with normalized vertical jump height as the dependent variable. RESULTS: The ANOVA results revealed that both ‘Feet came off ground during countermovement’ (p = 0.01) and ‘Rock back on heels’ (p = 0.03) had a significant effect on the normalized vertical jump height. However, ‘Where did they land?’ (p = 0.3) and ‘Knee Flexion in Air’ (p = 0.51) did not show a significant effect. CONCLUSION: The significant difference with whether an athlete’s feet came off the ground and whether they rock back on their heels suggest that preparatory actions during the countermovement phase can influence the outcome of the vertical jump. Future studies will investigate whether these findings can be applied to training a higher vertical jump and if they coincide with a larger population than just elite athletes.

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