TY - JOUR
T1 - Bandwidth optimization of the fatigue index to estimate muscle fatigue during dynamic contractions
AU - Kim, Jungyoon
AU - Kim, Soobyeong
AU - Park, Sunwoo
AU - Ahn, Soonjae
AU - Lee, Yongheum
AU - Kim, Youngho
N1 - Funding Information:
This research was financially supported by the Ministry of Knowledge Economy (MKE) and Korea Institute for Advancement of Technology (KIAT) through the Research and Development for Regional Industry (70011192). It was also supported by the Technology Innovation Program (Industrial Strategic Technology Development Program, 10032055) funded by the Ministry of Knowledge Economy (MKE, Korea).
PY - 2013/7
Y1 - 2013/7
N2 - In this study, a filter-based fatigue index (FIhlrOPT) was optimized to maximize the correlation with peak power. Cut-off frequencies of high-pass-filter were optimized to determine bandwidth for fatigue estimation. Thirty two subjects performed 5 sets of 10 knee extensions with 2 minutes of rest between each set. Surface electromyography (sEMG) signals were obtained from rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) muscles for each subject. The correlation of the proposed index was compared with sEMG-based fatigue indices, such as the mean root-mean-square (RMS) values, median frequency, median frequency after continuous wavelet transform, Dimitrov spectral index and Gonzalez-Izal wavelet index. The correlation of the index proposed in this study was higher (r = 0.81 ± 0.08 (RF), 0.58 ± 0.25 (VM & VL)) than those of the cited fatigue indices. The optimized cut-off frequencies in this study (353.30 ± 49.45 Hz (RF), 348.71 ± 34.28 Hz (VM & VL)) reflects the decreased firing rate during fatigue, and thus cut-off frequencies were appropriate for fatigue estimation.
AB - In this study, a filter-based fatigue index (FIhlrOPT) was optimized to maximize the correlation with peak power. Cut-off frequencies of high-pass-filter were optimized to determine bandwidth for fatigue estimation. Thirty two subjects performed 5 sets of 10 knee extensions with 2 minutes of rest between each set. Surface electromyography (sEMG) signals were obtained from rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) muscles for each subject. The correlation of the proposed index was compared with sEMG-based fatigue indices, such as the mean root-mean-square (RMS) values, median frequency, median frequency after continuous wavelet transform, Dimitrov spectral index and Gonzalez-Izal wavelet index. The correlation of the index proposed in this study was higher (r = 0.81 ± 0.08 (RF), 0.58 ± 0.25 (VM & VL)) than those of the cited fatigue indices. The optimized cut-off frequencies in this study (353.30 ± 49.45 Hz (RF), 348.71 ± 34.28 Hz (VM & VL)) reflects the decreased firing rate during fatigue, and thus cut-off frequencies were appropriate for fatigue estimation.
KW - Bandwidth optimization
KW - Electromyography
KW - Fatigue
KW - Filter
KW - Joint power
UR - http://www.scopus.com/inward/record.url?scp=84891916482&partnerID=8YFLogxK
U2 - 10.1007/s12541-013-0161-4
DO - 10.1007/s12541-013-0161-4
M3 - Article
AN - SCOPUS:84891916482
SN - 2234-7593
VL - 14
SP - 1185
EP - 1191
JO - International Journal of Precision Engineering and Manufacturing
JF - International Journal of Precision Engineering and Manufacturing
IS - 7
ER -