Table 2.

Fatigue indices in time domain.

Reference	Fatigue indices
Malinzak et al. [55]	Integrated EMG (IEMG)
Arabadzhiev et al. [56]	Root mean square (RMS)
Suetta et al. [57]	Mean absolute value (MAV)
Oskoei and Hu [58]	Modified mean absolute value type 1 (MAV1)
Villarejo et al. [59]	Modified mean absolute value type 2 (MAV2)
Phinyomark et al. [60]	Simple integral square (SSI)
Zardoshti-Kermani et al. [61]	Variance of EMG (VAR)
Tkach et al. [62]	v-order (V)
Zardoshti-Kermani et al. [61]	Log detector (LOG)
Kiguchi et al. [63]	Waveform length (WL)
Al Omari et al. [64]	Average amplitude change (AAC)
Siddiqi et al. [65]	Difference absolute standard deviation value (DASDV)
Kilbom et al. [66]	Zero crossing (ZC)
AlOmari and Liu [67]	Myopulse percentage rate (MYOP)
Phinyomark et al. [68]	Willison amplitude (WAMP)
Rogers et al. [69]	Slope sign change (SSC)
Buchenrieder [70]	Mean absolute value slope (MAVSLP)
Venugopal et al. [71]	Multiple hamming windows (MHW)
Du and Vuskovic [51]	Multiple trapezoidal windows (MTW)
Phinyomark et al. [72]	Histogram of EMG (HIST)
Al-Quraishi et al. [73]	Autoregressive coefficient (AR)
Chang et al. [74]	Cepstral coefficient (CC)