Pollical palmar interosseus muscle
Musculus interosseus palmaris pollicis
- Latin synonym: Adductor accessorius pollicis
- Synonym: Accessory adductor pollicis muscle
Definition
The pollical palmar interosseous muscle is located in the first metacarpal space (between the thumb and index finger). While some sources consider it the first palmar interosseous muscle, others view it as a rudimentary structure, often integrated with the adductor pollicis or flexor pollicis brevis. When present, it originates from the medial (ulnar) side of the palmar surface of the first metacarpal bone and inserts into both the base of the proximal phalanx of the thumb and its extensor hood. Its primary action is to adduct the thumb towards the index finger.
References
Valenzuela M, Bordoni B. Anatomy, Shoulder and Upper Limb, Hand Palmar Interosseous Muscle. [Updated 2025 Apr 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537165/
