During a physical assessment, if a patient has difficulty with dorsiflexion of the ankle, which nerve is most likely compromised?

In cases where a patient experiences difficulty with dorsiflexion of the ankle, the nerve most commonly compromised is the common peroneal nerve. This nerve is responsible for innervating the muscles that control dorsiflexion—specifically, the tibialis anterior muscle, which is crucial for lifting the foot upwards.

When the common peroneal nerve is injured or compromised, it can lead to weakness or paralysis in these dorsiflexors, resulting in difficulty in bringing the top of the foot toward the shin. This condition is often observed in cases such as foot drop, where the patient struggles to lift the foot adequately during walking. Understanding the specific roles of the nerves is vital in assessing motor deficits during a physical examination, and in this scenario, the common peroneal nerve's involvement in dorsiflexion directly points to its significance in the assessment of the patient's condition.