The "'dorsal surface "'( " facies dorsalis; posterior surface " ) is convex, and smooth in the upper third of its extent, and covered by the Abductor pollicis longus above, and the extensor pollicis brevis muscle below.
22.
The tendons of the extensor pollicis longus and extensor pollicis brevis form what is known as the anatomical snuff box ( an indentation on the lateral aspect of the thumb at its base ) The radial artery can be palpated anteriorly at the wrist ( not in the snuffbox ).
23.
The tendons of the extensor pollicis longus and extensor pollicis brevis form what is known as the anatomical snuff box ( an indentation on the lateral aspect of the thumb at its base ) The radial artery can be palpated anteriorly at the wrist ( not in the snuffbox ).
24.
On its upper part is an oblique ridge, which runs from the dorsal end of the radial notch, downward to the dorsal border; the triangular surface above this ridge receives the insertion of the Supinator, the abductor pollicis longus, the extensor pollicis longus, and the extensor indicis proprius.
25.
The fibres end approximately at the middle of the forearm in the form of a flat tendon, which is closely connected with that of the extensor carpi radialis longus, and accompanies it to the wrist; it passes beneath the abductor pollicis longus and extensor pollicis brevis, beneath the extensor retinaculum, and inserts into the lateral dorsal surface of the base of the third metacarpal bone, with a few fibres inserting into the medial dorsal surface of the second metacarpal bone.
