Definition
The Musculus tibialis posterior is a skeletal muscle that lies in the area of the calf and its attachment tendon extends around the inner ankle to the sole of the foot. It is officially classified as a lower leg muscle, which can be further divided into deep and superficial muscles. The M. tibialis posterior belongs to the deep muscle group.
It originates from the two lower leg bones and lies wedged between the two other muscles of the deep lower leg group. Due to its position and course, contraction results in an extension of the upper ankle joint, supination of the lower ankle joint and tension of the longitudinal and transverse arch of the foot. The nerve supply is provided by the tibial nerve.
Anatomy of the Musculus tibialis posterior
Anatomically correct, the muscle is counted among the deep flexor group. These three muscles all originate from one or both bones of the lower leg. The posterior tibialis muscle originates at the back of the tibia and fibula.
It also originates from a very taut membrane (Membrana interossea cruris) that lies between these two bones. On the lower leg, it lies between the flexor digitorum longus muscle and the flexor hallucis longus muscle. From here, after crossing the attachment tendon of the flexor digitorum longus below the inner ankle, the attachment tendon pulls over the upper and lower ankle joint to the sole of the foot.
Here the tendon attaches to several bones of the tarsal and the metatarsus. In addition to the superficial flexor group, the tibialis nerve also supplies the entire musculature of the deep flexor group with signals. Due to its anatomically deep position in relation to the body surface, injuries are rare.
The tendon of the posterior tibialis muscle, like all the tendons of the body that are connected to the muscles, consists of very taut collagen fibers that have a high tensile strength. The tendon begins at the lower end of the posterior tibialis muscle. However, the transition cannot be determined exactly.
The part of the lower leg that is farthest from the body is crossed with the attachment tendon of the flexor digitorum longus muscle. The attachment tendon of this muscle crosses the attachment tendon of the posterior tibialis muscle (“dig over tib”). However, this does not represent a hindrance in everyday life.
From there, the attachment tendon of the posterior tibialis muscle passes through the malleolar canal. This is located below the middle ankle. Here, all insertion tendons are encased by a tendon sheath to minimize friction between the individual tendons. The tendon is attached to the scaphoid, the sphenoid bones and the metatarsal bones.
