Muscle
Tibialis posterior
Deep leg muscle helping support the medial foot arch
High-yield
The navicular tuberosity is a major attachment, but the tendon reaches several other foot bones. Its arch-support role is shared with ligaments, joint alignment and other muscles.
Overview
Tibialis posterior lies between the long toe flexors and sends a tendon behind the medial malleolus. Its branching attachments across the midfoot let it turn the sole inward and help support the foot during weight bearing.
Reference facts
- Origin
- Upper posterior tibia and fibula, intervening interosseous membrane and adjacent fascial septa
- Insertion
- Mainly the navicular tuberosity, with variable slips to cuneiforms, cuboid, calcaneus and bases of metatarsals two through four
- Action
- Inverts the foot, assists ankle plantarflexion and supports the medial longitudinal arch
- Innervation
- Tibial nerve muscular branches, conventionally L4-L5
- Blood supply
- Chiefly posterior tibial branches, with fibular and sural contributions described
Mnemonic
Follow the tendon around the inner ankle toward the navicular: its medial route helps explain inward turning of the foot and support of the inner arch.
Clinical correlation
Posterior tibial tendon dysfunction can contribute to a progressively flattening foot. Progressive collapsing foot deformity involves several structures and can occur without a torn posterior tibial tendon.
Frequently asked questions
What does the tibialis posterior do?
The tibialis posterior inverts the foot, assists ankle plantarflexion and supports the medial longitudinal arch.
What nerve innervates the tibialis posterior?
The tibialis posterior is innervated by the tibial nerve muscular branches, conventionally L4-L5.
Where does the tibialis posterior attach?
Origin: Upper posterior tibia and fibula, intervening interosseous membrane and adjacent fascial septa. Insertion: Mainly the navicular tuberosity, with variable slips to cuneiforms, cuboid, calcaneus and bases of metatarsals two through four.
What is the blood supply of the tibialis posterior?
Chiefly posterior tibial branches, with fibular and sural contributions described.