Name
Pronunciation
(LUM-bri-culs) profundus
Origin/Proximal Attachment
Tendon of flexor digitorum
Insertion/Distal Attachment
Extensor hood of digits 2-5
Action/Relevance
Flexes the fingers (at the metacarpophalangeal joints) Extend interphalangeal joints
Innervation
1&2: Median nerve (C8, T1) 3&4: Ulnar nerve - deep branch (C8, T1)
Notes
The Lumbricales are four small fleshy fasciculi, associated with the tendons of the Flexor digitorum profundus. The first and second arise from the radial sides and volar surfaces of the tendons of the index and middle fingers respectively; the third, from the contiguous sides of the tendons of the middle and ring fingers; and the fourth, from the contiguous sides of the tendons of the ring and little fingers. Each passes to the radial side of the corresponding finger, and opposite the metacarpophalangeal articulation is inserted into the tendinous expansion of the Extensor digitorum communis covering the dorsal aspect of the finger.