add placement notes for each channel

Author: neuromechanist

emg_examples/sub-s2IndependentMod/emg/sub-s2IndependentMod_task-grasping_channels.tsv

@@ -1,7 +1,7 @@
-name	type	units	reference	interelectrode_distance	target_muscle
-EMG1	emg	V	bipolar	20 mm	Flexor carpi radialis
-EMG2	emg	V	bipolar	20 mm	Pronator teres
-EMG3	emg	V	bipolar	20 mm	Brachioradialis
-EMG4	emg	V	bipolar	20 mm	Flexor carpi ulnaris
-EMG5	emg	V	bipolar	20 mm	Extensor carpi radialis
-EMG6	emg	V	bipolar	20 mm	Extensor carpi ulnaris
+name	type	units	reference	interelectrode_distance	target_muscle	placement
+EMG1	emg	V	bipolar	20 mm	Flexor carpi radialis	near the elbow crease on the inner forearm
+EMG2	emg	V	bipolar	20 mm	Extensor radialis brevis	dorsal side of the forearm, about halfway between the elbow and the wrist
+EMG3	emg	V	bipolar	20 mm	Brachioradialis	upper forearm, about one-third of the way down from the elbow, on the lateral side
+EMG4	emg	V	bipolar	20 mm	Flexor digitorum superficialis	Locate the midpoint of the inner forearm
+EMG5	emg	V	bipolar	20 mm	Flexor carpi ulnaris	above the wrist on the inner forearm
+EMG6	emg	V	bipolar	20 mm	Abductor pollicis brevis	Over the fleshy area at the base of the thumb