The three plantar interossei arise with their single heads on the medial side of the third-fifth metatarsals and are inserted on the bases of the first phalanges of these digits.
They also provide motor innervation to quadratus plantae, abductor digiti minimi, flexor digiti minimi brevis, lateral three lumbricals, adductor hallucis, and the dorsal and plantar interossei.
In other mammals, the contrahentes may have their origin either on the carpus or the metacarpus, which suggests that the palmar interossei muscles also contain elements of the contrahentes.
There are many interossei in a human body.
Abduction is of little importance in the foot, but, together with the plantar interossei, the dorsal interossei also produce flexion at the metatarsophalangeal joints.
Between the toes, the dorsal and plantar interossei stretch from the metatarsals to the proximal phalanges of digits two to five.
The two heads of the four dorsal interossei arise on two adjacent metatarsals and merge in the intermediary spaces.
The second dorsal interossei from the medial side of the bone and the third dorsal interossei from the lateral side.
