Located mostly near the shin, on the horizontal side of the tibia, tibialis anterior originates on the tibia’s outside surface and extends down to where it inserts in each of the foot’s first metatarsal bones, and the medial cuneiform. Thick and fleshy along the top layer, this fusiform muscle is quite tendinous underneath, and is the most medial of the leg’s forward compartment.
Any activity that needs the leg to either move or remain vertical such as in walking, running, hiking, and skating, draws from the tibialis anterior. Serving as an ankle stabilizer, this muscle permits horizontal movement of the ankle, providing somewhat of a cushioning layer in the case the ankle rolls. Both a synergist and an antagonist of its sister muscle, the tibialis posterior, it receives its control from the deep peroneal nerve. In walking motions, tibialis anterior locks the ankle as the foot contacts the ground, and then pulls it back up.