Origin.—The origin is fleshy from a narrow elongate area on the mid-anterior surface of the tarsometatarsus between Mm. extensor brevis digiti IV and extensor hallucis longus, beginning at the distal end (bony) of the elongate accessory insertion of M. tibialis anticus. The distal part of the belly is free.
Insertion.—The attachment is by a thin, wide (relative to belly) tendon to the superficial surface of M. extensor brevis digiti III.
Innervation.—Not found.
Individual Variation.—In P.p. 1L, the muscle is less well developed. The fleshy belly is 1 × 5 mm. It arises from the lateral edge of M. extensor hallucis longus. The extremely slender insertional tendon attaches as above.
M. Extensor Brevis Digiti IV, [Figs. 19]E, [20]N
T. pallidicinctus
General Description and Relations.—Slender and tapering; on lateral part of anterior surface of tarsometatarsus; length of belly variable; middle of medial edge in contact with M. extensor hallucis longus.
Origin.—The origin is fleshy from the lateral part of the anterior surface of the tarsometatarsus, including the anterior metatarsal groove.
Insertion.—The long slender tendon enters the anterior aperture of the distal foramen, passes through the intertrochlear canal, emerges from the terminal foramen, and attaches to the medial surface of the proximal end of the first phalanx of digit IV.