Format

Send to

Choose Destination
J Electromyogr Kinesiol. 2019 Oct;48:121-127. doi: 10.1016/j.jelekin.2019.07.002. Epub 2019 Jul 6.

Maximal contraction methods influence the magnitude and reliability of global electromyographic signal characteristics.

Author information

1
Applied Neuromuscular Physiology Laboratory, Oklahoma State University, United States.
2
Applied Neuromuscular Physiology Laboratory, Oklahoma State University, United States. Electronic address: nathaniel.jenkins@okstate.edu.

Abstract

OBJECTIVE:

The purpose was two-fold: (1) to examine differences in maximal voluntary isometric torque (MVIT) production, and electromyographic signal amplitude (EMGAMP) and mean power frequency (EMGMPF) 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 EMGMPF 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 EMGAMP and EMGMPF 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 EMGAMP were greater during MVICRAMP than during MVICRAPID (p = 0.02 and 0.004). For EMGMPF, there were no significant differences among MVIC types. Although all MVIC types generally resulted in reliable measurements of MVIT and EMGAMP, reliability was stronger for EMGMPF 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 EMGAMP values and more reliable measurements of VL and RF EMGMPF.

KEYWORDS:

Frequency-domain; Intra-class correlation coefficient; Knee extensors; Neuromuscular; Time-domain

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center