Validity and Reliability of the Newly Developed Surface Electromyography Device for Measuring Muscle Activity during Voluntary Isometric Contraction
Table 2
Normalization of RMS and reliability of BTS-FREEEMG and PSL-EMG-Tr1.
Variable
Trial 1
Trial 2
ICC
Difference of means (95% CI)
value
(a) Biceps brachii muscle
80% MVIC (%)
BTS-FREEEMG
Week 1
78.92 ± 13.00
84.84 ± 18.92
0.321
−5.93 (−15.6, 3.7)
0.213
Week 2
81.44 ± 16.97
84.09 ± 19.76
0.185
−2.65 (−14.2, 8.9)
0.637
PSL-EMG-Tr1
Week 1
76.10 ± 14.83
82.08 ± 19.99
0.030
−5.98 (−17.8, 5.9)
0.306
Week 2
83.14 ± 15.51
82.62 ± 17.93
0.246
0.53 (−11.1, 12.2)
0.925
40% MVCI (%)
BTS-FREEEMG
Week 1
27.52 ± 10.17
26.83 ± 10.89
0.862
0.69 (−2.8, 4.2)
0.683
Week 2
26.86 ± 9.62
28.01 ± 11.22
0.662
−1.14 (−6.1, 3.8)
0.636
PSL-EMG-Tr1
Week 1
26.07 ± 9.39
24.43 ± 10.10
0.831
1.63 (−1.9, 5.2)
0.350
Week 2
26.07 ± 9.49
28.16 ± 11.58
0.307
−2.09 (−8.4, 4.3)
0.500
(b) Rectus femoris muscle
80% MVIC (%)
BTS-FREEEMG
Week 1
76.46 ± 18.41
79.91 ± 12.59
0.509
−3.45 (−11.9, 5.0)
0.406
Week 2
76.70 ± 12.19
78.22 ± 10.13
0.736
−1.53 (−6.4, 3.3)
0.517
PSL-EMG-Tr1
Week 1
74.87 ± 19.24
80.50 ± 11.95
0.547
−5.63 (−13.9, 2.7)
0.171
Week 2
77.56 ± 14.27
78.81 ± 10.54
0.580
−1.25 (−7.7, 5.2)
0.688
40% MVCI (%)
BTS-FREEEMG
Week 1
30.43 ± 7.32
32.11 ± 7.78
0.870
−1.68 (−4.0, 0.7)
0.152
Week 2
30.07 ± 8.18
31.07 ± 8.06
0.752
−1.01 (−4.4, 2.4)
0.545
PSL-EMG-Tr1
Week 1
29.93 ± 7.93
32.35 ± 8.23
0.765
−2.42 (−5.7, 0.8)
0.132
Week 2
30.69 ± 7.89
30.84 ± 7.93
0.828
−0.15 (−3.0, 2.7)
0.912
Values are number or mean ± SD. MVIC, maximum voluntary isometric contraction; ICC, intraclass correlation coefficients; paired t-test, ; CI, confidence interval.