A Systematic Review on Muscle Synergies: From Building Blocks of Motor Behavior to a Neurorehabilitation Tool

Figure 3

Procedure to extract MS from the NNMF multiplicative method. Synergies () were extracted from raw EMG data. EMG data is then shuffled and fed again to the algorithm with as fixed synergy, and activation coefficient () is allowed to be estimated. The EMG signal was reconstructed with and newly estimated activation coefficient (). Cross-validation is performed between the original () and the reconstructed EMG data.