The dorsal interossei are a group of intrinsic muscles within the foot. They form the deepest layer of plantar muscles and have a bipennate shape. Attachments: Originates from the lateral aspect of the metatarsals. The first muscle attaches to the medial side of the proximal phalanx of the second digit. The second to fourth interossei attach to the lateral sides of the proximal phalanxes of digits two to four. Actions: Abduction of the lateral four digits and flexion at the metatarsophalangeal joints. Innervation: Lateral plantar nerve. Blood Supply: Dorsalis pedis, dorsal metatarsal, lateral plantar and plantar metatarsal arteries. By TeachMeSeries Ltd (2025) Fig 5The fourth layer of the plantar muscles. Note the unipennate shape of the plantar interossei, and the bipennate shape of the dorsal interossei Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Print Article Rate This Article