| Autor: |
Muñoz, C X, Tran, T T, Brown, L E, Coburn, J W, Lynn, S K, Dabbs, N C, Gochioco, M K, Schick, E E, Khamoui, A V, Uribe, B P, Noffal, G J |
| Zdroj: |
Journal of Strength & Conditioning Research; 2011 Supplement, Vol. 25, pS70-S71, 2p |
| Abstrakt: |
Unassisted increased jump height subsequently increases descending velocity resulting in increased impact forces. Increased impact forces produce greater eccentric forces, which may lead to greater muscular adaptations. This is less well understood during an assisted jump. PURPOSE: The purpose of this study was to investigate the effects of different assisted jumping conditions on relative impact forces (RIF) and descent velocity (DV). METHODS: Thirty recreationally trained subjects (male = 15, female = 15) completed three testing sessions consisting of five experimental conditions: body weight reduction (BWR) of 0%, 10%, 20%, 30%, or 40%. In all conditions, subjects wore a full body harness while attached to two elastic cords, suspended and bolted to the ceiling. Subjects performed three maximal countermovement jumps with arm swing on a force plate with a velocity transducer for each condition. Maximum jump height (JH) values using a vertec for each condition were used for analyses. RESULTS: JH significantly (p < 0.05) increased across conditions (0% = 35.14 ± 9.02 cm, 40% = 79.44 ± 14.12 cm). Additionally, DV at 30% and 40% were significantly greater than 0%, 10%, and 20%, however, no differences were found between 30% and 40% (0% = 2.57 ± 0.30 m/s, 40% = 2.78 ± 0.35 m/s). Lastly, RIF was significantly greater across conditions from 10-30% (0% = 44.46 ± 9.12 N/kg, 30% = 57.66 ± 19.16 N/kg) when compared to 0%. Conclusion: Increased DV coupled with decreased body weight greater than 30% results in increased relative eccentric forces. Practical Applications: Assisted jumping at BWR ≥ 30% may augment eccentric forces and enhance muscular adaptations. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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