[Location] With the lateral wrists towards each other on the palm aspects and the fist slightly clenched, in the depression behind the (thenar eminence) root of the thumb (the first metacarpophlange ), on the junction of the red and white skin. ( Fig.4 )
 
[Regional Anatomy] Skin→subcutaneous tissue→abductor pollicis brevis→opponens pollicis brevis→flexor pollicis brevis. Superficial layer, the palmar cutaneous ramus of the median nerve, and superficial ramus of the radial nerve; deep layer, the muscular branch of the median nerve and of the ulnar nerve.