Tibialis Posterior Anatomy

Tibialis Posterior Muscle

Origin: Proximal two-thirds of the posterior surfaces of the tibia and the fibula and the interosseus membrane
Insertion: Passing behind the medial malleolus to attach to the bones that form the arch of the foot: the navicular, each cuneiform and cuboid the calcaneus and metatarsals 2,3,4
Actions: Plantarflexion and inversion of the foot
Innervation: Tibial nerve (L4, L5 )
Blood Supply: Branches from the anterior tibial artery and posterior tibial artery

Primary Actions of the Tibialis Posterior

1. Inversion of the foot at the subtalar joint

Agonists:

  • Tibialis Anterior

Antagonists:

  • Peroneus Longus
  • Peroneus Brevis

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Secondary Actions of the Tibialis Posterior

1. Assists with plantarflexion of the foot at the ankle
Agonists:

  • Gastrocnemius
  • Soleus

Antagonists:

  • Tibialis Anterior

Plantaris, peroneus longus, flexor hallucis longus, and flexor digitorum longus also assist with plantarflexion of the foot at the ankle.

2. Supports the medial longitudinal arch of the foot