Which muscle is primarily responsible for dorsiflexion of the foot?

The tibialis anterior is primarily responsible for dorsiflexion of the foot due to its anatomical positioning and function. This muscle is located in the anterior compartment of the leg and originates from the lateral condyle of the tibia and the adjacent interosseous membrane. When the tibialis anterior contracts, it pulls the foot upward at the ankle joint, which is the definition of dorsiflexion.

The role of dorsiflexion is crucial for activities such as walking, running, and climbing stairs, as it allows for proper foot clearance during the swing phase of gait. In addition to dorsiflexion, the tibialis anterior also assists in foot inversion, which adds to its significance in maintaining proper foot mechanics.

Other muscles listed, such as the soleus and gastrocnemius, primarily contribute to plantar flexion rather than dorsiflexion. The peroneus longus, meanwhile, is more involved in eversion and plantar flexion of the foot, making the tibialis anterior the clear answer for this question regarding primary dorsiflexion.