EMG spectral differences among the quadriceps femoris during the stretch reflex.
BACKGROUND
The purpose of this study was to examine the electromyographic (EMG) spectral characteristics of the quadriceps femoris muscles during tendon tap stretch reflexes.


METHODS
Sixteen healthy subjects (mean ± SD age = 21.2 ± 2.8 years) performed tendon tap reflexes of the leg extensors as surface EMG signals were detected from the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM) muscles of the dominant thigh. All EMG signals were processed with a wavelet analysis, and the resulting spectra were decomposed with nonparametric spectral decomposition.


RESULTS
The results showed that the spectra for the VL had significantly more high-frequency power than those for the RF and VM, with similar spectral shapes for the RF and VM.


CONCLUSIONS
These findings could be due to differences in the width of the innervation zone, or the fiber type composition of the muscles, although the latter seems to be more likely.
University of Oklahoma, Department of Health and Exercise Science, 110 Huston Huffman Center, Norman, Oklahoma, 73019-6081, USA.
Travis W
TW
Beck
University of Oklahoma, Department of Health and Exercise Science, 110 Huston Huffman Center, Norman, Oklahoma, 73019-6081, USA.
Jordon L
JL
Simmons
Oklahoma State University, Health and Human Performance Program, School of Applied Health and Educational Psychology, Stillwater, Oklahoma, USA.
Jason M
JM
Defreitas
D000293:Adolescent; D000328:Adult; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D052097:Quadriceps Muscle / Q000502:physiology*; D012026:Reflex, Stretch / Q000502:physiology*; D058067:Wavelet Analysis; D055815:Young Adult
electromyography; quadriceps femoris; spectra; stretch reflex; wavelet