Fibularis tertius muscle

The fibularis tertius muscle is only found in some people and is adjacent to the muscle belly of the extensor digitorum longus muscle. It's tendon distinctly attaches to the 5th metatarsal laterally and does not follow the same path as other extensor tendons that travel down the digits.

Action: Dorsiflexes and everts ankle

Innervation: Deep fibular nerve

Origin: Fibula

Insertion: 5th metatarsal