Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

Table 1

Three-way ANOVA for each of the six features with 95% confidence interval. The three factors and their considered interactions are subject, level of contraction (% MVC), and muscle fatigue factor (initial and final segments of the exercise), for isometric contraction and for the six features of sEMG.

Features	Effect of subject; 𝐹-value (𝑃)	Effect of level of contraction (% MVC); 𝐹-value (𝑃)	Effect of muscle fatigue; 𝐹-value (𝑃)
MDF	1.04 (0.31)	0.68 (0.41)	1.12 (0.42)
NRMS	1.44 (0.01)*	7.15 (0.01)*	0.51 (0.48)
RMS	2.51 (0.01)*	5.24 (0.04)*	0.68 (0.56)
WL	1.05 (0.02)*	2.58 (0.1)	0.85 (0.42)
NSM5	0.94 (0.548)	14.22 (0.001)^#	2.86 (0.093)
IIS index	0.78 (0.96)	4.57 (0.031)*	4288 (0.001)^#

∗Significant 𝑃<0.05; ^#𝑃<0.01.