Abstract
Objective: The purpose was two-fold: (1) to examine differences in maximal voluntary isometric torque (MVIT) production, and electromyographic signal amplitude (EMG(AMP)) and mean power frequency (EMG(MPF)) values obtained during traditional (MVICTRAD), rapid (MVICRAPID), and ramp (MVICRAMP) maximal voluntary isometric contractions, and (2) to determine if there were differences in the reliability of MVIT, EMGAMP and EMG(MPF) among the three MVIC types.
Approach: Twenty-two young males and females completed MVICTRAD, MVICRAPID, and MVICRAMP muscle actions on two separate visits separated by 48 h. During all MVICs, MVIT and EMG(AMP) and EMG(MPF) of the vastus lateralis (VL) and rectus femoris (RF) were quantified.
Main results: MVIT was greater during MVICTRAD and MVICRAPID than during MVITRAMP (both p < 0.001). VL and RF EMG(AMP) were greater during MVICRAMP than during MVICRAPID (p= 0.02 and 0.004). For EMG(MPF), there were no significant differences among MVIC types. Although all MVIC types generally resulted in reliable measurements of MVIT and EMG(AMP), reliability was stronger for EMG(MPF) quantified during the MVICRAMP.
Significance: Investigators may choose MVIC type based on preference or equipment availability. However, investigators should note that MVICRAMP contractions will likely yield the greatest EMG(AMP) values and more reliable measurements of VL and RF EMG(MPF).