Figure 2
Flow-chart of the analysis trunk muscle synergies (W) and their temporal patterns (C). W and C were extracted using the NMF algorithm. To determine if the extracted synergies in the current study represented the same underlying a variety of locomotion and stability tasks found in our previous study10, the similarities found using the scalar product of the cluster centroids of W in the current study, and those extracted in the previous study (excluding muscle weighting components in the lower limbs) were computed. The analysis of variability was focused on within-cluster similarities and similarities between session in both W and C. The similarity values for W and C were computed using scalar product and the rmax coefficient using the cross-correlation function, respectively.
