Summary Dorsal interossei (4 muscles) Origin Two heads from the proximal half of the sides of adjacent metatarsal bones Insertion The two heads of each muscle form a central tendon that insert on the bases of the second, third, and fourth proximal phalanges and into the aponeurosis of the tendons of EDL. The first is inserted into the medial side of the second toe; the other three are inserted into the lateral sides of the 2nd, 3rd, and 4th toes. Action Abduct MTP joint Innervation Lateral plantar nerve Arterial supply Anterior tibial artery via dorsalis pedis and dorsal metatarsal arteries; Posterior tibial artery via lateral plantar and plantar metatarsal arteries