All of the following muscles plantarflex the foot except for:

The tibialis anterior muscle is primarily known for its role in dorsiflexion of the foot rather than plantarflexion. Dorsiflexion involves lifting the foot upward toward the shin, while plantarflexion is the action of pointing the toes downwards or standing on the toes. The tibialis anterior is located along the front of the lower leg and functions to control and lift the foot, making it an essential muscle for activities such as walking and running, particularly during the swing phase when the foot is moving forward.

In contrast, each of the other muscles mentioned contributes directly to plantarflexion. The tibialis posterior supports arch stability and aids in plantarflexion, while the flexor hallucis longus facilitates the movement of the big toe and assists in plantarflexion as well. The peroneal muscles (peroneus brevis and longus) also play a critical role in helping to point the toes down and stabilize the foot during movement. Thus, the identification of the tibialis anterior as the exception to plantarflexion is accurate due to its primary function being the opposite, focusing on dorsiflexion.