The Anatomy of the Posterior Tibial Artery

A major artery that supplies parts of the lower leg and the foot

In This Article
Table of Contents

Arising from the popliteal artery behind the knee, the posterior tibial artery (PTA) delivers oxygenated blood to the posterior compartment of the lower leg as well as the plantar surface of the foot (the flat portion between the heel and the ball of the foot). This artery perforates the soleus muscle, one of the major muscles of the calf, as it moves downwards in a parallel course to the posterior tibial vein.

Clinically speaking, not only can arterial diseases affect the PTA, but it may also experience acute or chronic compartment syndrome, in which the artery is compressed because of inflammation of muscles due to injury or too much exercise. The latter conditions can lead to muscular, nerve, and blood circulation problems.

Anatomy

The PTA—alongside all lower-limb arteries—are supplied by the common femoral artery. Relatively larger, it emerges where the popliteal artery splits into anterior and posterior tibial arteries in an area called the popliteal fossa just behind each knee.

It progresses along its downward course first behind the popliteal muscle (a small muscle at the knee joint), then, after passing through the soleus, between the tibialis posterior and flexor digitorum longus muscles. The former of these is the most central leg muscles, and the latter a calf muscle that aids in foot flexion.

There are a number of important branches arising from this artery. The peroneal artery is major branch that usually splits off a couple of centimeters below the popliteus muscle. Furthermore, at the level of the talus—the bone that makes up the lower half of the ankle joint just above the heel bone or calcaneus—the PTA divides into the medial and lateral plantar arteries. The larger, second of these will then connect with the dorsalis pedis artery at the first and second metatarsal bones (the five bones that between the middle of the foot and the toes), creating an arterial arch underfoot.       

Anatomical Variations

Occasionally, doctors see significant differences in the anatomy of this artery. Among the variations seen is hypoplastic or aplastic PTA, meaning that the arteries are incompletely developed.

One study found this to occur only in the PTA in approximately 5% of cases, and in both this artery and the anterior tibial artery in another 0.8%. Trifurcation, in which three arteries arise instead of just the PTA and the anterior tibial artery occurs 1.5% of the time.  Finally, doctors have observed a higher than normal origin of this artery in rare cases.

Function

The PTA is a primary source of oxygenated blood to a couple of regions in the lower leg and feet. Specifically, this artery supplies the posterior compartment, a group of seven muscles that make up the curved surface as well as deeper parts of the calf.

As noted above, this artery splits into the medial and lateral plantar arteries at the level of the talus in the ankle. The former of these supplies the medial (middle) plantar (under) side of the foot, whereas the latter, larger artery, delivers to the heel and plantar portion closer to the side of the foot. As the artery connects with the dorsalis pedis artery, it creates the plantar arch that further supplies the toes and foot.     

Clinical Significance

Like most major arteries, the PTA can be implicated in a number of significant health issues. Peripheral artery disease, in which an artery becomes totally or partially blocked usually due to atherosclerosis (a hardening of vessels due to plaque build-up), can arise here. In these cases, leg cramping and pain can arise, especially after exertion such as walking up stairs. In addition, affected limbs may feel cold and numb. In the hospital or clinic, palpating (applying pressure with the hands) the PTA is an initial test for peripheral artery disease.

Untreated, peripheral artery disease can lead to gangrene (tissue death in the legs) and amputation, while also seriously increasing the risk of a heart attack. Luckily, there are both pharmaceutical treatments and minimally-invasive surgeries (for more developed cases) that are successful in managing the condition.

In addition, the PTA can be subject to a condition called compartment syndrome. In these cases, the artery becomes compressed due to inflammation in surrounding muscle groups, disrupting healthy circulation. In exertion or exercise-induced compartment syndrome, this swelling occurs due to physical exertion; whereas, injury in the legs can lead to acute compartment syndrome. Furthermore, a more permanent such compression, chronic compartment syndrome, can arise, something sometimes seen in long-distance runners.

This condition leads to severe pain, numbness, tingling in the legs and feet; this lasts anywhere from an hour after physical exertion to several days. In most cases, rest alone will take care of the problem, though surgeries are available if other approaches don’t work.

Was this page helpful?

Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Azam M, Shaw P. Anatomy, bony pelvis and lower limb, tibial artery. Ncbi.nlm.nih.gov. Published 2018. 

  2. Kil S, Jung G. Anatomical Variations of the popliteal artery and its tibial branches: Analysis in 1242 extremitiesCardiovasc Intervent Radiol. 2008;32(2):233-240. doi: 10.1007/s00270-008-9460-z