Research Article

A New Approach to Noninvasive-Prolonged Fatigue Identification Based on Surface EMG Time-Frequency and Wavelet Features

Table 4

Statistical analysis on the four muscle features.

Features (mean ± SD)
MusclesΔFmeanΔFmedΔMAVΔRMSΔ WIRM1551Δ WIRM1M51Δ WIRM1522Δ WIRE51ΔWIRW51

Biceps femorisNF−2.04 (10.4)−0.45 (9.74)−0.00034 (0.003)−0.00043 (0.004)0.80 (2.36)0.75 (2.33)0.09 (0.82)0.24 (0.78)0.22 (0.80)
PF7.55 (8.23)5.11 (6.46)−0.00033 (0.0028)−0.00049 (0.0037)−0.70 (2.69)−0.80 (2.30)−0.22 (0.85)−0.27 (0.92)−0.34 (0.98)

Rectus femorisNF−4.67 (9.91)−2.37 (6.67)−0.00061 (0.0018)−0.00066 (0.0024)1.02 (2.60)1.03 (2.64)0.36 (1.11)0.10 (1.02)0.10 (1.13)
PF5.77 (10.22)6.43 (8.56)0.001388 (0.0020)0.0017 (0.0024)−2.29 (2.51)−2.36 (2.61)−0.75 (0.76)−0.66 (1.01)−0.74 (1.14)

Vastus lateralisNF−2.07 (8.45)−2.15 (9.00)−0.00038 (0.0022)−0.00054 (0.0029)0.40 (2.74)0.66 (2.66)0.17 (0.94)0.13 (0.87)0.11 (0.88)
PF6.34 (7.85)4.64 (7.58)−0.00052 (0.0024)−0.00064 (0.0031)−0.59 (2.38)−0.60 (2.41)−0.21 (0.83)−0.26 (0.85)−0.25 (0.92)

Vastus medialisNF−0.75 (7.59)−0.30 (7.42)0.0001 (0.002)0.0001 (0.003)0.58 (2.74)0.54 (3.17)0.24 (1.02)0.12 (0.96)0.11 (0.95)
PF4.06 (4.81)4.28 (5.77)0.00022 (0.0024)0.000246 (0.0032)−0.330 (1.75)−0.38 (1.73)−0.10 (0.96)−0.02 (0.66)−0.01 (0.58)

The differences differ significantly tested using the t-test at  < 0.05.