Figure 4.

Three consecutive repetitions per type of movement are displayed, distinguished by color for selected pairs of electrodes recorded in parallel on the residual arm of participant P6 (A) and the intact arm of a control participant (B). Both PHM-related and IHM-related EMG Signals were concatenated over different types of movements. The different types of movements are flexion (Flex) and extension (Ext) of thumb (F1), index (F2), middle finger (F3) and little finger (F5), closing (CIS) and opening (Opn) of hand and pinch. For each pair of electrodes, the signal is normalized by the maximum peak EMG amplitude found over all movement types and expressed in percentage. (A) Upper trace: proximal location on the medial head of triceps brachialis (TB); second trace: distal location on the medial head of TB; third trace: distal location on the lateral head of TB; lowest trace: distal location on BB. (B) Upper trace: proximal location on the medial head of biceps brachialis (BB); second trace: distal location on the medial head of BB; third trace: distal location on the lateral head of BB; lowest trace: superficial finger flexor muscle. Note that the lack of phasic activity in the intact arm muscles resulted in high normalized values, misleadingly suggesting high EMG levels.