Responses of mechanomyography, electromyography, and peak torque to three days of velocity-specific isokinetic training
The purpose of this investigation was to determine the effects of three days of velocity-specific isokinetic training on strength, mechanomyography (MMG), and electromyography (EMG). Thirty adult females were randomly assigned to a control (CON; n = 10), slow velocity training (SVT; n = 10), or fast velocity training (FVT; n = 10) group. All subjects performed maximal, concentric isokinetic muscle actions of the leg extensors at 30, 150, and 270°·s −1 on a Cybex II dynamometer for the determination of PT on visits 1 and 5. During each test, EMG and MMG measurements were recorded. The training groups performed 4 sets of 10 reps at 30°·s −1 (SVT group) or 270°·s−1 (FVT group) on visits 2, 3, and 4. For the SVT group, PT increased from pre-test to post-test at 30, 150, and 270°·s−1. The increase in PT at 30°·s−1 was greater than at 150 and 270°·s−1. For the FVT group, PT increased at 270°·s−1 only. There were no significant increases in PT for the CON group. There were no significant pre-test to post-test changes in EMG amplitude or MPF for any group at any velocity with the exception of a significant decrease in EMG amplitude from pre-test to post-test at 150°·s−1 for the CON group, and a significant increase in EMG MPF (VM muscle only) from pre-test to post-test at 270°·s−1 for the FVT group. There were no significant pre-test to post-test changes in MMG amplitude or MPF at any velocity for any group with the exception of increases in MMG amplitude at 150°·s−1 and 270°·s−1 for the SVT and FVT groups, respectively. The lack of a consistent pattern of increases for EMG and MMG amplitude and MPF suggested that the training-induced increases in PT were not due to increased muscle activation. Instead, the increased PT may have been due to decreased coactivation of the antagonist hamstrings muscles and/or coordination and learning of stabilizing muscles.
0575: Sports medicine