Origin | Posterior surface of tibia Posterior surface of fibula Posterior interosseous membrane |
Insertion | Navicular bone tubercle Medial cuneiform bone Intermediate cuneiform bone Lateral cuneiform bone Cuboid bone Bases of the 2nd, 3rd and 4th metatarsal bones |
Action | Foot plantar flexion Foot inversion Supports medial arch of foot |
Nerve | Tibial Nerve (L4, L5) |
Artery | Posterior tibial artery |
Location & Overview
The tibialis posterior muscle is the deepest muscle in the posterior compartment of the lower leg. The other deep muscles in the posterior compartment of the lower leg are: the flexor digitorum longus, the flexor hallucis longus and the popliteus. The tibialis posterior is not able to be palpated as it is covered by the large superficial muscles of the lower leg; the gastrocnemius and soleus [1] [2] [3].
Here we can see pictured the tibialis posterior from a posterior view (the back of the lower leg).
Here we can see a picture of the distal tendon of the tibialis posterior from a medial view (the inner side of the leg).
Origin & Insertion
The tibialis posterior originates from the posterior surface of the upper half of the tibia, the posterior surface of the upper half of the fibula, and the posterior side of the interosseus membrane. The tibialis posterior then continues in an inferior direction down the leg crossing the ankle joint (posterior to the medial malleolus) and inserting to bones underneath of the foot (on the plantar aspect). The insertion points located on the plantar aspect of the foot are: the navicular bone tubercle, medial cuneiform bone, intermediate cuneiform bone, lateral cuneiform bone, cuboid bone; and the bases of the 2nd, 3rd and 4th metatarsal bones [4] [5] [6].
Here we can see two of the origins of the tibialis posterior muscle marked out in red. It is originating on the posterior surface of tibia and the posterior fibula.
Here we can see another origin of the tibialis posterior muscle marked out in red. It is originating on the interosseous membrane which is a thick dense fibrous sheet of connective tissue that spans between the tibia and fibula.
Here we can see the insertion points of the tibialis posterior underneath the foot. These insertion points are on the navicular bone tubercle, medial cuneiform bone, intermediate cuneiform bone, lateral cuneiform bone, cuboid bone, and the bases of the 2nd, 3rd and 4th metatarsal bones.
Actions
The tibialis posterior is a primary inverter of the foot. The other primary foot inverter of the foot is the tibialis anterior. The tibialis posterior is also able to assist the gastrocnemius, soleus, and plantaris muscles in causing plantar flexion of the foot. The tibialis posterior is also able to support the medial arch of the foot (the tibialis anterior is also able to assist in supporting this medial arch too) [7] [8] [9].
Innervation
The tibialis posterior muscle is innervated by the tibial nerve. The tibial nerve is a component of the sciatic nerve originating from the ventral rami of spinal roots L4-S3 [10] [11].
Blood Supply
Blood is supplied to the tibialis posterior primarily from the posterior tibial artery. The posterior tibial artery arises from the popliteal artery [12].
Want some flashcards to help you remember this information? Then click the link below:
Tibialis Posterior Flashcards
References
↑1, ↑4, ↑7, ↑10, ↑12 | Corcoran NM, Varacallo M. Anatomy, Bony Pelvis and Lower Limb, Tibialis Posterior Muscle. [Updated 2021 Aug 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539913/ |
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↑2, ↑5, ↑8 | Park JH, Kim D, Kwon HW, Lee M, Choi YJ, Park KR, Youn KH, Cho J. A New Anatomical Classification for Tibialis Posterior Tendon Insertion and Its Clinical Implications: A Cadaveric Study. Diagnostics (Basel). 2021 Sep 4;11(9):1619. doi: 10.3390/diagnostics11091619. PMID: 34573961; PMCID: PMC8466387. |
↑3, ↑6, ↑9 | Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017. |
↑11 | Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017 |