The Reliability of EMG Parameters During Walking on the Stairs and an Inclined Surface

The use of electromyography (EMG) parameters depends on their reliability. The purpose of this study was to determine the reliability of common EMG parameters recorded from muscles of lower extremity during walking on the stairs and an inclined surface.
Subjects and Fourteen healthy young males went up the stairs and an inclined surface with normal speed and after 30s rest went down. This was repeated 5 times with 1 min intervals. At the same time, surface EMG of rectus femoris, vastus medialis, vastus lateralis, and tibialis anterior muscles were recorded. In time domain, integrated EMG (IEMG) and root mean square of EMG (RMS), and in frequency domain, median frequency (MF) and mean power frequency (MPF) were calculated. Intra-class correlation coefficients and standard error of measurement for each parameter were calculated.
The average relative and normalized absolute reliability of iEMG and RMS were higher than MF and MPF. The average relative and normalized absolute reliability in going up were better than going down. In overall, there was no difference between the reliability of RMS and IEMG and also between MF and MPF.
Differed reliability of EMG parameters in various movement conditions emphasizes the need to have reliability measures for all parameters of each muscle in conducting researches.