Fig. 1

Experimental setup. a Positioning of the electrode arrays A1-A3 during the recording. b Anatomical landmarks and paths used for the positioning of the arrays: A1 (6 rows, 16 columns) was placed over the forearm covering Anconeus, Brachioradialis and Pronator Teres muscles, where the most proximal row of electrodes was placed ~2 cm bellow the elbow crest (EC) covering all three muscles, according to [46]; A2 (6 rows, 12 columns) was placed in the distal part of the upper arm with respect to the center of the line connecting fossa cubit (FC) and acromion (AC), and covering Biceps Brachii muscle; A3 (6 rows, 12 columns) was placed in the proximal part with respect to the center of the line connecting EC and AC, over Triceps Brachii. Both A2 and A3 arrays were located in accordance with SENIAM recommendations [33]. Reference electrodes (R) were placed on the clavicle, wrist and shoulder of the active arm. c Detail of the electrode arrays used in the experiment