Upper limb
Adductor Pollicis, Oblique Head
Musculus adductor pollicis (caput obliquum)
- Origin
- Capitate bone and bases of the 2nd and 3rd metacarpals
- Insertion
- Ulnar side of the base of the proximal phalanx of the thumb, via a sesamoid bone
- Function
- Adduction of the thumb; the larger of the two heads
- Innervation
- Ulnar nerve, deep (motor) branch, C8-T1
- Movement & chain
- Major agonist for thumb adduction toward the second and third metacarpals alongside the transverse head.
- Palpation
- Deep in the 1st web space on the palmar side between capitate and thumb base; felt as deep firmness on strong adduction.
- Clinical
- Innervated by deep branch of ulnar nerve; paralysis causes a positive Froment sign (compensatory FPL hyperflexion of thumb IP).
- Segmental innervation
- Ulnar nerve, C8-T1.
- In clinical practice
- Focus on hand function and edema prevention; ensure IV cannulas and splints maintain functional hand position to prevent joint contractures.
- Region in the model
- Upper limb