Table 2.

Reference guidelines available in literature for sensor location on the brachioradialis muscle, when assessed by bipolar sEMG.

Author, Year	Criterion	Sensor Location
Basmajian, 1983 [16]	Minimum crosstalk area, determined experimentally	“With the hand pronated and the elbow bent, draw a line from the ¾ point of the elbow skin crease to the styloid process of the radius (in the snuff-box). Place both electrodes centered in an oval area approximately 25–30% the distance from the elbow skin crease to the styloid process of the radius”. This placement refers exclusively to miniaturized electrodes, i.e., with a diameter of a few millimeters, placed next to each other or with a minimum center-to-center distance.
Cram, 1998 [10]	Muscle anatomy	“Palpate the muscle mass just distal to the elbow while resisting elbow flexion with the wrist in the neutral position (thumb up). Two active electrodes, 2 cm apart, are placed approximately 4 cm distally from the lateral epicondyle of the elbow on the medial fleshy mass that covers that area, so that they run parallel to the muscle fibers.”
Barbero, 2012 [14]	Away from the innervation zone	With the elbow extended, draw “a line from the styloid process to a midpoint on the line between the lateral and medial epicondyles. Optimal electrode site: Between 32% and 100% of this line”, starting from the epicondyle (i.e., avoid the very proximal part of the muscle belly, where the innervation zone is most likely located). No indication on electrode size is provided but small electrodes are assumed.