Second Plantar Interosseous (Musculus interosseus plantaris secundus)
Educational content only — not medical advice.
Anatomy
The second bipennate plantar interosseous, arising from the base and medial side of the fourth metatarsal and inserting on the medial base of the proximal phalanx of the fourth toe. It adducts the fourth toe toward the axis of the second toe (PAD).
Origin & insertion
From the base and medial side of the fourth metatarsal, to the medial base of the proximal phalanx of the fourth toe with the extensor hood.
Action
Adducts the fourth toe toward the second and flexes its metatarsophalangeal joint.
Innervation
Lateral plantar nerve (S2–S3).
Clinical notes
Selective wasting between the third and fourth metatarsals is best felt in the web-space squeeze test; distinguishing interosseous from lumbrical involvement needs the plantar-versus-dorsal relation to the deep transverse ligament.
Related structures
Educational references
FAQ
What is the role of the Second Plantar Interosseous?
The second bipennate plantar interosseous, arising from the base and medial side of the fourth metatarsal and inserting on the medial base of the proximal phalanx of the fourth toe. It adducts the fourth toe toward the axis of the second toe (PAD).
Why is the Second Plantar Interosseous clinically important?
Selective wasting between the third and fourth metatarsals is best felt in the web-space squeeze test; distinguishing interosseous from lumbrical involvement needs the plantar-versus-dorsal relation to the deep transverse ligament.
Source & license
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