Question

which muscle is highlighted?
flexor digitorum longus
tibialis posterior
flexor hallucis longus
popliteus

Explanation:

The flexor digitorum longus is located in the posterior compartment of the leg. It runs down the leg and is involved in flexing the toes. The tibialis posterior is deeper and more towards the inner side. The flexor hallucis longus is more towards the outer posterior side and flexes the big toe. The popliteus is a small muscle at the back of the knee. Based on the anatomical position shown (running along the leg and its relation to other structures in a typical leg muscle diagram), the highlighted muscle matches the flexor digitorum longus.

Answer:

flexor digitorum longus