Force-Time Analysis of the Drop Jump: Reliability of Jump Measures and Calculation Methods for Measuring Jump Height

ABSTRACT

The purpose was to evaluate reliability of measurements during drop jump (DJ) and magnitude of differences in vertical jump height (VJH) when calculated using two variables: time-in-the-air and center-of-mass velocity. Thirty-seven handball players performed three single-leg and double-leg DJs on a portable force plate during two sessions. Sixteen outcome measures and four sets of reliability metrics, including intraclass correlation coefficients (ICCs), were estimated. All outcome measures, except vertical time-to-stabilization, yielded high (0.70–0.89) to very high (0.90–0.96) interday and intraday ICCs for the single-leg and double-leg DJ tests. These results indicated that the single-leg and double-leg DJ tests can be considered reliable for short-term and long-term monitoring of collegiate handball players of both sexes. In addition, the single-leg DJ VJH calculated using these two variables differed in magnitude (mean difference in test measurements: 0.64 cm, p < .001, effect size: 0.165). Therefore, we recommend using the same method to calculate single-leg VJH for long-term monitoring.

KEYWORDS:

• vertical jump test
• vertical jump height
• handball
• single and double leg drop jump
• athlete monitoring

Acknowledgments

This research was partially supported by The Scientific and Technological Research Council of Turkey. The datasets generated and analyzed during the current study are not publicly available, but are available from the corresponding author upon request. The authors declare that there is no conflict of interest.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The work was supported by the Türkiye Bilimsel ve Teknolojik Araştırma Kurumu [219S813].