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JOURNAL
OF
SPORTS SCIENCE &
MEDICINE
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Research
article
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THE EFFECTS OF KINETIC ENERGY ON CONCENTRIC AND ECCENTRIC ISOKINETIC WORK |
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Brian Boggess1, Jeff Moffit2  ,
Jacobo Morales3 and Tim Anderson3 |
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1California Department of Corrections Southern Testing Center, Rancho Cucamonga, CA, USA, 2California State University, Bakersfield, Bakersfield, CA, USA, 3California State University, Fresno, Fresno, CA, USA |
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© Journal of Sports Science and Medicine (2008) 7, 84 - 90 Search Google Scholar for Citing Articles |
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| ABSTRACT | |||
| This investigation examined inertial effects on work output during
isokinetic concentric knee extension and eccentric knee flexion. Total work
(Wtotal) included work due to kinetic energy (Wkin), with respect to gravity
(Wgrav), and against the dynamometer (Wdyn). Eighteen resistance-trained
participants (9 males, 9 females) performed maximal voluntary concentric
(90, 150, 210, 270 deg/s) and eccentric (-150, -90, -30 deg/s) actions with
the dominant leg. Differences between work measurement type (WMT), i.e.,
gravity-corrected work and Wtotal, were assessed. ANOVA (2 WMT x 2 mode
x 2 gender x 4 speed) revealed significant main effects (p < 0. 05) for
both factors concentrically but only for WMT eccentrically. It was concluded
that the effect of kinetic energy during isokinetic leg extension may elicit
differences in measurement where the associated error (Kerr) significantly
increases with increasing velocity concentrically and decreases eccentrically.
Key words: Kinetic energy, kinetic error, work measurement type. |
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