Which muscle is innervated by the common fibular nerve and is responsible for dorsiflexion of the foot?

Explanation

## Common Fibular Nerve and Foot Dorsiflexion **Key Point:** The **tibialis anterior** muscle is the primary dorsiflexor of the foot and is innervated by the **deep fibular (peroneal) nerve**, a terminal branch of the common fibular nerve. ### Common Fibular Nerve Branches and Motor Supply **High-Yield:** The common fibular nerve divides into two main branches: 1. **Deep Fibular Nerve** (anterior compartment of leg) - Tibialis anterior (dorsiflexion) - Extensor hallucis longus (dorsiflexion of great toe) - Extensor digitorum longus (dorsiflexion of toes) - Fibularis tertius (dorsiflexion) 2. **Superficial Fibular Nerve** (lateral compartment of leg) - Fibularis longus (eversion) - Fibularis brevis (eversion) ### Clinical Correlation: Common Fibular Nerve Palsy **Warning:** Common fibular nerve injury (at the neck of fibula) results in: - **Foot drop** — inability to dorsiflex the foot - **Steppage gait** — patient lifts knee higher to clear the drooping foot - **Loss of sensation** over the dorsum of the foot and lateral leg - **Preserved ankle plantarflexion** (tibial nerve intact) **Clinical Pearl:** Common fibular nerve is the most frequently injured nerve in the lower limb due to its superficial course around the fibular neck (common site of tourniquet application, pressure injury, or trauma). ### Mnemonic for Foot Movements and Innervation **"DELF"** — Dorsiflexion = **L**ateral (fibular nerve); Eversion = **L**ateral (fibular nerve); Plantarflexion = **T**ibial; inversion = **T**ibial