The tibialis refers to a group of muscles located in the lower leg, primarily responsible for foot movement. The two main muscles in this group are the tibialis anterior and the tibialis posterior. The tibialis anterior helps lift the foot and is crucial for walking, running, and maintaining balance. The tibialis posterior plays a key role in supporting the arch of the foot and assists in foot inversion, which is the movement of turning the sole inward. Both muscles are essential for various activities, including sports and daily movements, contributing to overall leg and foot function.