Quick Facts
Origin: Tubercle of trapezium bone and flexor retinaculum of hand.
Insertion: Anterolateral aspect of body of first metacarpal bone.
Action: Opposes thumb towards other fingers.
Innervation: Recurrent branch of median nerve (C8-T1).
Arterial Supply: Superficial palmar branch of radial artery and princeps pollicis artery.
Related parts of the anatomy
Origin
The opponens pollicis muscle originates from the:
- tubercle of trapezium bone;
- flexor retinaculum of hand.
Insertion
The fibers of the opponens pollicis muscle travel inferolaterally to the thumb and insert onto the anterolateral aspect of the body of first metacarpal bone.
Key Features & Anatomical Relations
The opponens pollicis muscle is found in the thenar compartment of the hand. It is a short, quadrilateral type of skeletal muscle. It is located:
- anterior (superficial) to the first metacarpal bone;
- posterior (deep) to the abductor pollicis brevis muscle;
- lateral to the flexor pollicis brevis muscle.
Actions & Testing
The opponens pollicis muscle opposes the thumb towards the fingers. This movement consists of:
- medial rotation of the first metacarpal bone (of thumb) at the first carpometacarpal joint;
- flexion of the first metacarpal bone at the first carpometacarpal joint (Moore, Dalley and Agur, 2009).
The opponens pollicis muscle can be tested by opposing the thumb to the little finger against resistance (Sinnatamby, 2011).
References
Moore, K. L., Dalley, A. F. and Agur, A. M. R. (2009) Clinically Oriented Anatomy. Lippincott Williams & Wilkins.
Sinnatamby, C. S. (2011) Last's Anatomy: Regional and Applied. ClinicalKey 2012: Churchill Livingstone/Elsevier.
