Figure 3.
Evaluation of voluntary activation of conventional muscle synergies of a typical subject. Upper panels show muscle synergies extracted by NVAF(A), NCD(B), and NAD(C). Lower panels show the MNIIA of each tested muscle synergy. MNIIA is the maximum normalized IIA in one trial (Figure 2), and its value denotes parallelism between the muscle activity of the subject and the tested muscle synergy (Figure 1A). Horizontal red bars denote the values of the index of random activation NIIA(mrand). The asterisk indicates that the following two criteria are satisfied: (1) the MNIIA is significantly larger than 0 (p < 0.025), and (2) the MNIIA is significantly larger than the NIIA(mrand) (p < 0.025).