Posterior tibial tendinopathy is an injury to the tendon that produces pain and swelling, and limits movement. The affected tendon in this pathology is found in the posterior tibia, which is fundamental in the functioning of the ankle and foot.
The posterior tibia is an elongated muscle in the leg, located in the calf. The insertion of this muscle goes from the tibia, the fibula, and the interosseous membrane (that connects both bones) toward the part below.
This muscle continues its path in the form of a tendon, passing behind the tibial malleolus, which is the part inside the ankle. Later, it enters in the scaphoid or navicular bone, which is the part above the arch of the foot.
There is also insertion in the wedge-shaped ones and in the three central metatarsals, the bones that are in the front of the foot. As you can see, the muscle and tendon occupy a good part of the foot and ankle. Therefore, their proper functioning is decisive.
What is posterior tibial tendinopathy?
As we’ve already pointed out, posterior tibial tendinopathy is an injury to the tendon by the same name. The word tendinopathy is a generalist term used to refer both to tendinitis and tendinosis. Therefore, when we talk about posterior tibial tendinopathy, we’re alluding to both types of injuries.
Tendinitis involves the swelling of the tendon, while tendinosis refers to a degenerative process of the same. However, many researchers consider the term tendinitis to be unprecise in this case and that tendinopathy is a more appropriate term.
Posterior tibial tendinopathy causes important limitations in the movement of the foot and ankle. This is due to the fact that the posterior tibia carries out important functions, such as:
- Plantar flexion of the ankle. This is the movement that brings the tip of the foot downward.
- Supination of the ankle. When the sole of the food is directed inward and upward.
- When resting the foot on the floor, the posterior tibia inhibits the pronation and internal rotation of the tibia. In other words, it keeps the leg from rotating inward.
Causes of Tendinopathy
Posterior tibial tendinopathy is an injury that occurs as the result of overuse and mainly affects runners and trekkers. It occurs due to anatomical and/or biomechanical factors.
Among the anatomical and biomechanical factors that lead to posterior tibial tendinopathy, excessive pronation stands out. This is the normal inward turning of the foot that occurs when we walk. Quite frequently, excessive pronation is the result of having flat feet. This condition places undue stress on the tendon.
Another anatomical factor is excess weight or a high body mass index (BMI). At the same time, previous inflammatory illnesses, neurological conditions, or degenerative changes in the joints all play a role. Posterior tibial tendinopathy is more most frequent in women over the age of 40.
In regard to improper practices or the use of inadequate materials, the main causes are the use of improper footwear, overuse, and poor techniques when walking or running. Muscle weakness and lack of flexibility in the muscles of the ankle can also be influential.
Characteristics and other interesting information
The evolution of posterior tibial tendinopathy involves four different phases. Each phase has its own trademark symptoms, which are the following:
- Stage I. Pain in the inner part of the ankle when making movements involving the inversion of the foot or palpation of the tendon. There is also swelling in the area.
- Stage II. The previous symptoms persist, along with having a hard time remaining on tiptoes. The arch of the foot gradually flattens and, when observing the feet from behind, you can often observe the “too many toes” sign.
- Stage III. The previous symptoms continue, along with the arrival of new symptoms, including the deformity of the foot, which is now flat. Degenerative changes also appear in the tibiofibular talar joint.
Posterior tibial tendinopathy, like other tendinopathies, may even lead to the rupturing of the tendon. Early treatment and the neutralization of the underlying cause significantly improve the prognosis of this illness. In the most serious of cases, surgery may be necessary.