[TA] intrinsic muscle of dorsum of foot; origin, dorsal surface of calcaneus; insertion, by four tendons fusing with those of the extensor digitorum longus, and by a slip attached independently to the base of the proximal phalanx of the great toe; action, extends four lateral toes (II-V); nerve supply, deep fibular. SYN: musculus extensor digitorum brevis [TA], musculus extensor brevis digitorum, short extensor (muscle) of toes.