Dorsal Interossei Muscles, Plantar View

Description

Plantar exposure of the forefoot and midfoot centers on the dorsal interossei, seen as bipennate intrinsic muscles occupying the intermetatarsal spaces between the first through fifth metatarsals. Their bellies lie deep to the plantar aponeurosis and superficial to the metatarsals, with tendons coursing distally toward the bases of the proximal phalanges and the extensor expansions at the metatarsophalangeal joints. The deep plantar arterial arch is positioned proximal to the metatarsal heads, spanning from lateral to medial across the bases of the metatarsals, with the interossei arranged around it and separated by the metatarsals and intermetatarsal ligaments. Joint cartilage at the metatarsophalangeal and interphalangeal articulations is indicated to orient the insertions relative to the digital rays. Small muscles, tight spaces. Functionally, the dorsal interossei abduct digits 2 through 4 from the second toe axis and assist lumbricals in flexion at the metatarsophalangeal joints with extension at the interphalangeal joints, so their line of pull matters when teaching toe alignment during gait and push-off. This plantar perspective also clarifies why surgical dissection around the deep plantar arch and proximal intermetatarsal spaces demands restraint, the plantar metatarsal arteries and deep branch of the lateral plantar nerve run in the same neighborhood where interosseous compartments are opened for infection drainage or approached during metatarsal osteotomy exposure. The relationship to the metatarsal heads provides a clean map for understanding transverse metatarsalgia and instability patterns. Podiatry and gross anatomy courses use this plate to anchor intrinsic foot muscle layers and to connect tendon insertions with metatarsophalangeal biomechanics. It also suits surgical atlases discussing plantar approaches to the intermetatarsal spaces, deep plantar arch injury risk, and compartmental spread in forefoot infections. Anatomical accuracy verified by SciePro's Medical Advisory Board.