Opponens digiti minimi muscle of hand
Musculus opponens digiti minimi manus
- Related terms: Opponens digiti minimi
Definition
Opponens digiti minimi muscle of hand | |||
Origin | Hook of hamate, flexor retinaculum | ||
Insertion | Medial border of the 5th metacarpal | ||
Innervation | Deep branch of the ulnar nerve (C8 and T1) | ||
Artery | Ulnar artery | ||
Action | Opposition of the 5th digit (little finger) | ||
Antagonist | Extensor digiti minimi muscle | ||
Origin and insertion
The opponens digiti minimi muscle of hand is one of the intrinsic hypothenar muscles. It originates from the hook of the hamate and the adjoining part of the flexor retinaculum (transverse carpal ligament) and inserts along the ulnar side of the fifth metacarpal shaft.
Innervation
The muscle is innervated by the deep branch of the ulnar nerve (C8, T1).
Action
Its primary function is to flex and laterally rotate the fifth metacarpal, enabling opposition of the little finger toward the thumb, which is essential for grip and fine motor tasks.
References
Okwumabua E, Sinkler MA, Bordoni B. Anatomy, Shoulder and Upper Limb, Hand Muscles. [Updated 2023 Jul 24]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537229/
Loss J, Li ZM. Biometry of thenar muscle origins on the flexor retinaculum. Clin Anat. 2020 Nov;33(8):1176-1180.
