Lower limb
Tibialis Posterior
Musculus tibialis posterior
- Origin
- Interosseous membrane and adjacent surfaces of the tibia and fibula
- Insertion
- Mainly the tuberosity of the navicular bone, with extensions to the cuneiform bones and the base of the middle metatarsals
- Function
- Plantarflexion and inversion of the foot; supports the medial longitudinal arch
- Innervation
- Tibial nerve (L4-L5)
- Movement & chain
- Primary dynamic stabilizer of the medial longitudinal arch; eccentrically active during pronation in the stance phase of gait.
- Palpation
- Palpable behind the medial malleolus, just anterior to the tendon of flexor digitorum longus, during resisted inversion.
- Clinical
- Dysfunction or rupture of the tibialis posterior tendon is the main cause of adult-acquired flatfoot.
- Segmental innervation
- Tibial nerve, L4-L5.
- In clinical practice
- In clinical examination for tibialis posterior dysfunction, attention is paid to the 'too many toes' sign and inability to perform a single-leg heel rise, characteristic of adult-acquired flatfoot.
- Region in the model
- Lower limb