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Published on: September 13, 2015
EMG spectral differences among the quadriceps femoris during the stretch reflex
Travis W Beck1, Jordon L Simmons1, Jason M Defreitas2
1University of Oklahoma, Department of Health and Exercise Science, 110 Huston Huffman Center, Norman, Oklahoma, 73019-6081, USA.
Introduction:
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.
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