Motor Unit Decomposition Over Intrinsic Hand Muscles During Single and Multi-finger Flexion

High density surface electromyography allows us to record multiple channels of muscle electrical activity data that can be decomposed further into motor unit (MU) spike trains. Current work on MU decomposition analysis is mainly focused on lower-limb muscles given that more MUs can be identified in them. Nonetheless, MUs decoding when performing different hand gestures provides valuable knowledge that can be built from offline decomposition over existing open-source datasets. Particularly, little attention has been paid to MU activity over intrinsic hand muscles. This work analyses MU decomposition results and spatial features over intrinsic hand muscles during individual and multi-finger movements. We used an open dataset consisting of 20 participants performing 12 different hand gestures. The results can be used in future experiments to improve tasks design and electrode grid placement, and to maximise MU count depending on the finger movements studied.