Test-retest reliability of jump execution variables using mechanography: a comparison of jump protocols |
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| Authors: | John S Fitzgerald LuAnn Johnson Grant Tomkinson Jesse Stein James N Roemmich |
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| Institution: | 1. Human Performance Laboratory, Department of Kinesiology and Public Health Education, University of North Dakota, Grand Forks, ND, USA;2. Grand Forks Human Nutrition Research Center, United States Department of Agriculture, Grand Forks, ND, USA;3. Alliance for Research in Exercise, Nutrition and Activity (ARENA), School of Health Sciences &4. Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia |
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| 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. |
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| Keywords: | Reliability mechanography vertical jump rate of force development |
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