The interossei of the third and fourth digits are alike.
Origin from the ventral surface of the base of the metatarsal. The muscles cover the ventral surface of the shaft. At the head each divides and passes onto the sides of the metatarsal.
Insertion.—Each half of the muscle shows a tendency to divide into two parts. One of these, the more superficial and ventral, ends in a tendon which joins the extensor tendon near the distal end of the first phalanx. The other part is inserted by short tendon- and muscle-fibres into the side of the base of the first phalanx; one of the parts is therefore a middle, and the other a long, adductor or abductor, the adductores and abductores digiti tertii and quarti.
The fifth digit has five short muscles.
M. abductor medius digiti quinti.
Origin from the ventral surface of the calcaneus and from the fifth metatarsal.
Insertion by a slender tendon into the lateral side of the base of the first phalanx of the fifth digit.
M. adductor medius digiti quinti.
Origin with the adductor medius digiti secundi.
Insertion on the inner side of the base of the phalanx of the fifth digit.