Tendon of second dorsal interosseous muscle
Tendo musculi interossei dorsale secondi
Definition
The tendon of second dorsal interosseous muscle inserts into the radial side of the base of the proximal phalanx of the middle finger and its extensor hood. Functionally, the primary role of the second dorsal interosseous muscle is to abduct (spread) the middle finger radially, moving it away from the hand's central axis. Additionally, via its connection to the dorsal aponeurosis (extensor hood), it assists in flexion at the metacarpophalangeal (MCP) joint and extension at the interphalangeal (IP) joints of the middle finger.
References
Valenzuela M, Bordoni B. Anatomy, Shoulder and Upper Limb, Hand Dorsal Interossei Muscle. [Updated 2025 Apr 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK536922/