Opponens Digiti Minimi of Foot (Musculus opponens digiti minimi)
Educational content only — not medical advice.
Anatomy
A variable muscle of the third layer of the sole, usually described as a deep slip of the flexor digiti minimi brevis rather than a separate muscle, and absent in many feet. When present it runs from the base of the fifth metatarsal to the shaft of the same bone — the only "opponens" of the foot, though true opposition as in the hand does not occur here.
Origin & insertion
From the base of the fifth metatarsal and the long plantar ligament, to the lateral shaft of the fifth metatarsal.
Action
Deepens the lateral arch and draws the fifth metatarsal head plantarward; an accessory flexor-adductor of the little toe.
Innervation
Lateral plantar nerve (S2–S3).
Clinical notes
Its variability matters in sonography of the lateral sole: the muscle belly seen deep to the flexor digiti minimi brevis is reported as an accessory muscle, and confusion with a soft-tissue mass is a recognised imaging pitfall.
Related structures
Educational references
FAQ
What is the role of the Opponens Digiti Minimi of Foot?
A variable muscle of the third layer of the sole, usually described as a deep slip of the flexor digiti minimi brevis rather than a separate muscle, and absent in many feet. When present it runs from the base of the fifth metatarsal to the shaft of the same bone — the only "opponens" of the foot, though true opposition as in the hand does not occur here.
Why is the Opponens Digiti Minimi of Foot clinically important?
Its variability matters in sonography of the lateral sole: the muscle belly seen deep to the flexor digiti minimi brevis is reported as an accessory muscle, and confusion with a soft-tissue mass is a recognised imaging pitfall.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details