Abductor Digiti Minimi of Foot (Musculus abductor digiti minimi)
Educational content only — not medical advice.
Anatomy
The most lateral muscle of the first layer, lying along the lateral border of the sole on the plantar surface of the fifth metatarsal. Despite its name it acts more as a flexor of the little toe at the metatarsophalangeal joint than as a true abductor. It is the largest of the superficial sole muscles and its bulk forms the lateral margin of the foot.
Origin & insertion
From the lateral and medial processes of the calcaneal tuberosity and the intermuscular septum, to the lateral side of the base of the proximal phalanx of the little toe.
Action
Abducts and flexes the little toe at the metatarsophalangeal joint.
Innervation
Lateral plantar nerve (S1–S3).
Clinical notes
Atrophy of this muscle is the MRI signature of Baxter neuropathy — entrapment of the first branch of the lateral plantar nerve under the medial head of the quadratus plantae, a recognised cause of chronic inferior heel pain in runners. Denervation here is also an electromyographic sign of an S1 radiculopathy.
Related structures
Educational references
FAQ
What is the role of the Abductor Digiti Minimi of Foot?
The most lateral muscle of the first layer, lying along the lateral border of the sole on the plantar surface of the fifth metatarsal. Despite its name it acts more as a flexor of the little toe at the metatarsophalangeal joint than as a true abductor. It is the largest of the superficial sole muscles and its bulk forms the lateral margin of the foot.
Why is the Abductor Digiti Minimi of Foot clinically important?
Atrophy of this muscle is the MRI signature of Baxter neuropathy — entrapment of the first branch of the lateral plantar nerve under the medial head of the quadratus plantae, a recognised cause of chronic inferior heel pain in runners. Denervation here is also an electromyographic sign of an S1 radiculopathy.
Source & license
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