Comparison of Initialization Techniques for the Accurate Extraction of Muscle Synergies from Myoelectric Signals via Nonnegative Matrix Factorization

Figure 1

Synchronous muscle synergy model. In this graphical example, two different commands , indicating the temporal activation coefficients, are sent to the mixing matrix , consisting of four synergy vectors. The single command is distributed to the muscle according to the muscle weighting . The inverse problem to be solved by a factorization algorithm is the accurate identification of the underlying structures and starting from the measurement of .