Not an inverter of foot is
**Core Concept**
The question pertains to the muscles of the foot, specifically their functions and classifications as inverters or everters. Inversion and eversion are movements of the foot around the talocrural joint, where inversion refers to the movement of the foot inward (medially) and eversion refers to the movement outward (laterally).
**Why the Correct Answer is Right**
The muscles responsible for foot movements are primarily innervated by the tibial nerve (for inverters) and the peroneal nerve (for everters). The correct answer is likely a muscle that is not primarily involved in foot inversion. The primary inverters of the foot include the tibialis posterior, flexor digitorum longus, and flexor hallucis longus muscles, which are innervated by the tibial nerve.
**Why Each Wrong Option is Incorrect**
* **Option A:** This muscle is primarily responsible for foot inversion, specifically the movement of the foot inward. It is innervated by the tibial nerve and plays a crucial role in maintaining balance and preventing excessive foot eversion.
* **Option B:** This muscle is also primarily involved in foot inversion, contributing to the movement of the foot inward. It is innervated by the tibial nerve and works in conjunction with other inverters to maintain foot stability.
* **Option C:** This muscle is primarily responsible for foot eversion, the movement of the foot outward. It is innervated by the peroneal nerve and plays a crucial role in foot mobility and balance.
**Clinical Pearl / High-Yield Fact**
The primary inverters of the foot (tibialis posterior, flexor digitorum longus, and flexor hallucis longus) are often weakened in patients with posterior tibial tendon dysfunction, a common cause of flatfoot deformity.
**Correct Answer: C. Peroneus longus**