Isokinetic Leg-Press Power–Force–Velocity Profiles Are Reliable in Male and Female Elite Athletes but Not Interchangeable With Vertical Jump Profiles
in International Journal of Sports Physiology and PerformanceClick name to view affiliation
Purpose: To evaluate the test–retest reliability of isokinetic leg-press power–force–velocity profile (P–F–v) parameters in male and female elite athletes. In addition, we determined the concurrent validity of leg-press against squat-jump (SJ) P–F–v parameters in task-experienced athletes. Methods: For test–retest reliability, 22 female and 23 male elite athletes (22.3 [4.1] y) with different sporting backgrounds conducted 3 isokinetic leg-press test sessions over 3 consecutive weeks. The testing consisted of bilateral leg extensions at isokinetic velocities of 0.1, 0.3, 0.7, and 1.2 m·s−1. For concurrent validity, 13 ski jumpers (20.3 [3.3] y) were recruited to perform the isokinetic leg-press and SJ P–F–v profile tests using 5 predefined loading conditions of 0%, +20%, +40%, +60%, and +80% of body mass. Results: Relative and absolute reliability were acceptable for female (intraclass correlation coefficient ≥.87 and coefficient of variation ≤6.5%) and male (intraclass correlation coefficient ≥.89 and coefficient of variation ≤5.7%) elite athletes. In contrast, concurrent validity was insufficient, with correlations ranging from −.26 to .69 between isokinetic and SJ P–F–v parameters. Conclusion: Irrespective of sex, isokinetic leg-press P–F–v profiles provide reliable parameters. However, leg-press P–F–v profiles do not serve as a valid substitute for SJ P–F–v profiles. P–F–v parameter magnitudes are likely dependent on the constraints of the tested movement and testing device.
Dirnberger https://orcid.org/0000-0001-8526-2832
Wiesinger https://orcid.org/0000-0001-8526-2832
Fessl (isabella.fessl@plus.ac.at) is corresponding author, https://orcid.org/0000-0001-5892-5127
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