A 24-year-old female received a small-caliber bullet wound to the popliteal fossa from a drive-by assailant. The patient was admitted to the emergency department, where the surgeons recognized that the bullet had severed the tibial nerve. Such an injury would most likely result in which of the following?

**Core Concept**
The tibial nerve is a branch of the sciatic nerve, which arises from the L4-S3 nerve roots. It is responsible for innervating the muscles of the posterior compartment of the leg, including the gastrocnemius and soleus, which control plantarflexion of the foot.

**Why the Correct Answer is Right**
The tibial nerve injury would lead to foot drop, characterized by the inability to dorsiflex the foot. This is due to the damage to the muscles of the anterior compartment of the leg, including the tibialis anterior, which are responsible for dorsiflexion. The patient would likely experience difficulty walking, with the foot slapping against the ground with each step. The absence of sensation in the plantar surface of the foot would also be a key feature of this injury.

**Why Each Wrong Option is Incorrect**
**Option A:** Weakness in toe extension would not be a primary consequence of tibial nerve injury, as the tibial nerve primarily innervates the muscles responsible for plantarflexion.

**Option B:** Inability to flex the knee would not be a direct result of tibial nerve injury, as the tibial nerve does not innervate the muscles responsible for knee flexion.

**Option C:** Decreased ankle jerk reflex would be a consequence of tibial nerve injury, as the tibial nerve is responsible for transmitting signals from the gastrocnemius muscle to the spinal cord.

**Clinical Pearl / High-Yield Fact**
A patient with a tibial nerve injury may exhibit a decreased or absent ankle jerk reflex, due to the damage to the afferent fibers of the reflex arc.

**Correct Answer:** C. Decreased ankle jerk reflex.

✓ Correct Answer: C. A dorsiflexed and everted foot