Plantar interossei muscles

The plantar interossei, three in number, lie beneath rather than between the metatarsal bones, and each is connected with but one metatarsal bone.

They arise from the bases and medial sides of the bodies of the third, fourth, and fifth metatarsal bones, and are inserted into the medial sides of the bases of the first phalanges of the same toes, and into the aponeuroses of the tendons of the Extensor digitorum longus.