Differences in Maximum Voluntary Excitation Between Isometric and Dynamic Excitation are Age Dependent.

Differences in Maximum Voluntary Excitation Between Isometric and Dynamic Excitation are Age Dependent.
J Appl Biomech. 2019 Mar 12;:1-20
Authors: Baggen RJ, van Dieën JH, Verschueren SM, Van Roie E, Delecluse C
Abstract
In older populations, obtaining true maximum voluntary excitation appears more difficult than in young populations. The aims of this study were to determine whether differences between maximum voluntary excitation obtained from voluntary isometric contractions (MVIC) versus (sub-)maximum voluntary dynamic contractions (s-)MVDC) are age-dependent, and how normalizing EMG signals to corresponding maximum voluntary excitations affects variance between participants and the likelihood of normalized signals exceeding 100%. MVIC, s-MVDC and MVDC were recorded in ten young women, and MVIC and s-MVDC in nineteen older women. A significant age x contraction mode interaction effect was found for vastus lateralis (p = 0.037). In young women MVDC elicited highest maximum voluntary excitation for vastus lateralis and rectus femoris (p < 0.05). In older women, no differences in maximum voluntary excitation were found (p > 0.05). Normalization to dynamic contractions resulted in lower between-participant variance of EMG amplitudes, though not for all muscles, and decreased the amount of normalized signals exceeding 100% in young women. These findings indicate that differences in maximum voluntary excitation across contraction...

Source: Journal of Applied Biomechanics - March 14, 2019 Category: Sports Medicine Tags: J Appl Biomech Source Type: research