The tibialis posterior muscle is the most central of all the leg

muscle Skeletal muscles (commonly referred to as muscles) are organs of the vertebrate muscular system and typically are attached by tendons to bones of a skeleton. The muscle cells of skeletal muscles are much longer than in the other types of mus ...

s, and is located in the deep posterior compartment of the leg. It is the key stabilizing muscle of the lower leg.

Structure

The tibialis posterior muscle originates on the inner posterior border of the

fibula The fibula or calf bone is a leg bone on the lateral side of the tibia, to which it is connected above and below. It is the smaller of the two bones and, in proportion to its length, the most slender of all the long bones. Its upper extremity ...

laterally. It is also attached to the

interosseous membrane An interosseous membrane is a thick dense fibrous sheet of connective tissue that spans the space between two bones, forming a type of syndesmosis joint. Interosseous membranes in the human body: * Interosseous membrane of forearm * Interosseous ...

medially, which attaches to the tibia and fibula. The

tendon A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...

of the tibialis posterior muscle (sometimes called the posterior tibial tendon) descends posterior to the

medial malleolus A malleolus is the bony prominence on each side of the human ankle. Each leg is supported by two bones, the tibia on the inner side (medial) of the leg and the fibula on the outer side (lateral) of the leg. The medial malleolus is the promi ...

. It terminates by dividing into plantar, main, and recurrent components. The main portion inserts into the tuberosity of the navicular bone. The smaller portion inserts into the plantar surface of the medial cuneiform. The plantar portion inserts into the bases of the second, third and fourth metatarsals, the intermediate and lateral cuneiforms and the

cuboid In geometry, a cuboid is a hexahedron, a six-faced solid. Its faces are quadrilaterals. Cuboid means "like a cube", in the sense that by adjusting the length of the edges or the angles between edges and faces a cuboid can be transformed into a c ...

. The recurrent portion inserts into the

sustentaculum tali In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock. S ...

of the calcaneus. Blood is supplied to the muscle by the posterior tibial artery.

Nerve supply

The tibialis posterior muscle is supplied by the tibial nerve.

Function

The tibialis posterior muscle is a key muscle for stabilization of the lower leg. It also contracts to produce

inversion Inversion or inversions may refer to: Arts * , a French gay magazine (1924/1925) * ''Inversion'' (artwork), a 2005 temporary sculpture in Houston, Texas * Inversion (music), a term with various meanings in music theory and musical set theory * ...

of the foot, and assists in the plantarflexion of the foot at the ankle. The tibialis posterior has a major role in supporting the medial arch of the foot. Dysfunction of the tibialis posterior, including rupture of the tibialis posterior tendon, can lead to flat feet in adults, as well as a valgus deformity due to unopposed eversion when

is lost.

Clinical significance

Injury to the distal

of the tibialis posterior muscle is rare. It may be caused during

exercise Exercise is a body activity that enhances or maintains physical fitness and overall health and wellness. It is performed for various reasons, to aid growth and improve strength, develop muscles and the cardiovascular system, hone athletic ...

. It usually presents with pain on the medial side of the ankle. Injuries including dislocations and tears often require surgery.

Additional images

File:Gray259.png, Bones of the right leg. Posterior surface. File:Gray269.png, Bones of the right foot. Plantar surface. File:Gray357.png, Coronal section through right talocrural and talocalcaneal joints. File:Tibialis posterior.png, Muscles of the back of the leg. Deep layer. File:Gray445.png, Muscles of the sole of the foot. Third layer. File:Gray551.png, The popliteal, posterior tibial, and peroneal arteries. File:Slide1ACA.JPG, Muscles of the back of the leg. Deep layer. File:Slide2ACA.JPG, Muscles of the back of the leg. Deep layer. File:Slide2ACCA.JPG, Muscles of the leg.Posterior view. File:Slide1ADA.JPG, Muscles of the sole of the foot. File:Slide3Bubu.JPG, Dorsum of Foot. Ankle joint. Deep dissection File:Slide2bubu.JPG, Dorsum of Foot. Ankle joint. Deep dissection. File:Slide2wewe.JPG, Ankle joint. Deep dissection. Medial view

References

External links

*
Diagram at washington.edu

Diagram at latrobe.edu.au
{{Authority control Calf muscles Muscles of the lower limb