What are the primary functions of the tibialis posterior muscle?

The primary functions of the tibialis posterior muscle include both plantar flexion and inversion of the foot. The tibialis posterior is located deep in the posterior compartment of the leg and plays a crucial role in stabilizing the foot and maintaining the arch.

During plantar flexion, the muscle contracts to help point the toes downward, which is essential for activities such as walking, running, and jumping. Inversion, on the other hand, involves turning the sole of the foot inward, which is important for maintaining balance and stability on uneven surfaces.

This understanding of the tibialis posterior’s actions is central to some clinical considerations, particularly when assessing the foot's mechanics and addressing conditions such as flatfoot or posterior tibial tendon dysfunction. Strengthening this muscle is often a focus in rehabilitation programs for injuries related to the ankle and foot.