peroneotibial

from The Century Dictionary.

• Of or pertaining to the perone or fibula and the tibia; tibiofibular.
• noun A muscle in some marsupial animals, and also in reptiles and batrachians, passing downward obliquely from the fibula to the tibia in the place of the usual interosseous membrane.
• noun 2. An anomalous muscle in man, occurring about once in seven cases, arising from the inner side of the head of the fibula, and inserted into the oblique line of the tibia. It is constant in apes. Also called pronatortibiæ.