Test-retest reliability of jump execution variables using mechanography: a comparison of jump protocols. Issue 9 (3rd May 2018)

• Record Type: Journal Article
• Authors: Fitzgerald, John S.; Johnson, LuAnn; Tomkinson, Grant; Stein, Jesse; Roemmich, James N.
• Is Part Of: Journal of sports sciences. Volume 36:Issue 9(2018)
• Page Start: 963
• Page End: 969
• Publication Date: 2018-05-03
• Subjects: Reliability -- mechanography -- vertical jump -- rate of force development; Sports -- Periodicals; Sports -- Physiological aspects -- Periodicals; Sports -- Psychological aspects -- Periodicals; 612.044
• DOI: 10.1080/02640414.2017.1346818
• Languages: English
• ISSNs: 0264-0414

Abstract

ABSTRACT: Mechanography during the vertical jump may enhance screening and determining mechanistic causes underlying physical performance changes. Utility of jump mechanography for evaluation is limited by scant test-retest reliability data on force-time variables. This study examined the test-retest reliability of eight jump execution variables assessed from mechanography. Thirty-two women (mean±SD: age 20.8 ± 1.3 yr) and 16 men (age 22.1 ± 1.9 yr) attended a familiarization session and two testing sessions, all one week apart. Participants performed two variations of the squat jump with squat depth self-selected and controlled using a goniometer to 80º knee flexion. Test-retest reliability was quantified as the systematic error (using effect size between jumps), random error (using coefficients of variation), and test-retest correlations (using intra-class correlation coefficients). Overall, jump execution variables demonstrated acceptable reliability, evidenced by small systematic errors (mean±95%CI: 0.2 ± 0.07), moderate random errors (mean±95%CI: 17.8 ± 3.7%), and very strong test-retest correlations (range: 0.73–0.97). Differences in random errors between controlled and self-selected protocols were negligible (mean±95%CI: 1.3 ± 2.3%). Jump execution variables demonstrated acceptable reliability, with no meaningful differences between the controlled and self-selected jump protocols. To simplify testing, a self-selected jump protocol can be used to assess force-time variables with negligible impact on measurement error.