Quick Facts
Origin: Tubercles of scaphoid and trapezium bones, flexor retinaculum of hand.
Insertion: Lateral aspect of base of proximal phalanx of thumb.
Action: Abducts thumb at its carpometacarpal joint.
Innervation: Recurrent branch of median nerve (C8-T1).
Arterial Supply: Superficial palmar branch of radial artery.
Related parts of the anatomy
Origin
The abductor pollicis brevis muscle originates from the:
- tubercle of scaphoid bone;
- tubercle of trapezium bone;
- flexor retinaculum of hand.
Insertion
The fibers of the abductor pollicis brevis muscle travel inferolaterally to the thumb and insert onto the:
- lateral aspect of the base of the proximal phalanx of thumb;
- tendon of extensor pollicis longus.
Key Features & Anatomical Relations
The abductor pollicis brevis muscle is found in the thenar compartment of the hand. It is a short, fusiform type of skeletal muscle. It is located:
- anterior (superficial) to the opponens pollicis muscle;
- lateral to the flexor pollicis brevis muscle and the palmar aponeurosis.
Actions & Testing
The abductor pollicis brevis muscle abducts the first metacarpal bone (of thumb) at the first carpometacarpal joint, which occurs when the abductor pollicis longus muscle contracts simultaneously with it.
The abductor pollicis brevis muscle can be tested by abducting the first metacarpal at its carpometacarpal joint against resistance, during which it can be seen and palpated (Sinnatamby, 2011).
References
Sinnatamby, C. S. (2011) Last's Anatomy: Regional and Applied. ClinicalKey 2012: Churchill Livingstone/Elsevier.
