Okay, let's tackle this question about common peroneal nerve injury. First, I need to recall the anatomy and function of the common peroneal nerve. The common peroneal nerve is a branch of the sciatic nerve, right? It wraps around the fibular head and divides into the superficial and deep peroneal nerves. So, injuries here can affect the muscles it innervates.

The question is asking what may occur in such an injury. The options aren't listed, but the correct answer is likely to be foot drop. Because the common peroneal nerve innervates the muscles responsible for dorsiflexion and eversion of the foot. So if it's injured, the patient can't lift their foot, leading to foot drop. Also, there might be sensory loss over the dorsum of the foot and the lateral leg.

Wait, but what about the other options? Let's think. If the options included foot drop, then that's correct. Other possible options might be like loss of plantar flexion, which would be incorrect because the tibial nerve is responsible for that. Or maybe sensory loss in the sole of the foot, which is also tibial nerve territory. Another option could be weakness in ankle inversion, but inversion is from the tibialis posterior, which is tibial nerve as well. So peroneal nerve injury would cause weakness in eversion, not inversion.

Clinical pearl: Remember that common peroneal nerve injuries often occur at the fibular head, so when you see a foot drop, check for peroneal nerve damage. Also, patients might have a steppage gait. High yield fact: The common peroneal nerve is the most commonly injured branch of the sciatic nerve in lower limb trauma.

**Core Concept**
The common peroneal nerve (a branch of the sciatic nerve) innervates muscles responsible for **dorsiflexion** and **eversion** of the foot. Injury to this nerve typically results in **foot drop** and sensory deficits over the **dorsum of the foot** and **lateral leg**.

**Why the Correct Answer is Right**
Foot drop occurs due to paralysis of the **tibialis anterior** and **extensor digitorum longus**, which are innervated by the common peroneal nerve. Sensory loss over the dorsum of the foot and lateral leg results from damage to the **superficial peroneal nerve** (a branch of the common peroneal nerve). The nerve is vulnerable at the **fibular head**, a common site for trauma or compression.

**Why Each Wrong Option is Incorrect**
**Option A:** Loss of plantar flexion is incorrect—this is caused by tibial nerve injury, not peroneal.
**Option B:** Weakness in ankle inversion is incorrect—inversion relies on the tibialis posterior (tibial nerve), not peroneal.
**Option C:** Sensory loss on the sole of the foot is incorrect—the tibial nerve, not peroneal, supplies the sole.

**Clinical Pearl / High-Yield Fact**
Foot drop with a "steppage gait" is a hallmark of common peroneal nerve injury. Always assess dorsiflexion strength and sensation over the first web space to localize lesions. Remember: **

✓ Correct Answer: B. Foot drop