Which nerve injury could result in an inability to perform dorsiflexion of the foot?

The inability to perform dorsiflexion of the foot is primarily associated with injury to the common peroneal nerve. This is because the common peroneal nerve branches into the deep fibular nerve, which innervates the muscles responsible for dorsiflexion, such as the tibialis anterior. Damage to the common peroneal nerve can lead to weakness or a complete inability to lift the foot, resulting in a condition known as foot drop.

In contrast, the femoral nerve is primarily involved in hip flexion and knee extension and does not directly affect the movements of the foot. The tibial nerve is responsible for innervating the muscles involved in plantarflexion and does not play a role in dorsiflexion. Although the deep fibular nerve specifically innervates the muscles that facilitate dorsiflexion, if the common peroneal nerve is compromised before it branches into the deep fibular, the resultant dysfunction can also involve the deep fibular nerve, manifesting as an inability to dorsiflex the foot. Therefore, the initial injury to the common peroneal nerve can lead to significant deficits in dorsiflexion functions.