The tibialis posterior is a sizable, deep muscle located in the posterior compartment of the lower leg, forming part of the calf.

Origin:
Interosseous membrane, posterior surfaces of the tibia and fibula.

Insertion:
Navicular and medial cuneiform bones, as well as the bases of the second, third, and fourth metatarsal bones.

Function:
Primarily responsible for plantarflexion and inversion of the foot, providing essential support to the medial arch and contributing to overall foot stability during weight-bearing activities.

Heel Raise (Calf Raise)

Seated Heel Raise (Seated Calf Raise)