The abductor pollicis brevis passes forward and reaching the proximal phalanx of the thumb inserts onto the lateral side of its base. It is a thenar muscle , and therefore contributes to the bulk of the palm's thenar eminence . This muscle is responsible for the thumb's abduction, and also plays a role in opposition of the thumb. Review Topic. Insertion: Splits into two tendon slips going to lateral base of proximal phalanx of thumb and extensor apparatus of thumb. Derek Moore 0 % Topic. Origin. 0. The main function of the abductor pollicis brevis is to abduct the thumb. Ulnar: Flexor carpi ulnaris, flexor digitorum profundus (half), palmaris brevis, flexor digiti minimi, abductor digiti minimi, opponens digiti minimi, adductor pollicis, flexor pollicis brevis (deep head), palmar and dorsal interossei, and third and fourth lumbricals. The abductor pollicis brevis is a flat, thin muscle located just under the skin. Action. • Innervation Route: C8, T1 → median nerve → thenar branch → abductor pollicis brevis branch. Origin: Flexor retinaculum, tubercle of trapezium and tubercle of scaphoid bone. Abductor Pollicis Brevis. Description. Abductor pollicis brevis muscle is the most lateral and superficial of the three muscles forming the thenar eminence.. It is a thenar muscle and consequently contributes to the bulk of the palm’s thenar eminence. It originates from the flexor retinaculum of the hand , the tubercle of the scaphoid bone, and additionally sometimes from the tubercle of … Innervation. abductor pollicis brevis, opponens pollicis, and first and second lumbricals. The adductor pollicis is a flat, triangular muscle, lying deep in the thenar compartment. Attachment of the Abductor Pollicis Brevis Origin: The abductor pollicis brevis muscle originates from the flexor retinaculum of the hand, the tubercle of the […] Overview of Anatomy and Physiology; Structural Organization of the Human Body; Functions of Human Life; Requirements for Human Life; Homeostasis; Anatomical Terminology; Medical Imaging; The Chemical Level of Organization. The adductor pollicis (or adductor pollicis muscle, latin: musculus adductor pollicis) is one of the four thenar muscles lying on the radial side of the palm.. The adductor pollicis arises with two heads: the oblique and the transverse head.. The abductor pollicis brevis is innervated by the median nerve. 0. The abductor pollicis brevis is a hand muscle which controls some of the movement of the thumb. It takes its origin from the front of transverse carpal ligament, extending into the tubercles of scaphoid and trapezium with an occasional contribution from the tendon of abductor pollicis longus.. Insertion Origin. The abductor pollicis brevis muscle is a flat & thin muscle located just under the skin.