It is a normal phenomenon for the foot to get larger over a lifetime of use. Ligaments lose their tensile strength and tendons can lengthen over time making the shape and size of the foot change. However, these changes happen over a long period of time, making them unnoticeable from month to month. The only situation is which noticeable changes happen normally would be in pregnancy, since women have hormones in their body which are meant to make ligaments more flexible to allow for child birth. But have you noticed that your arch has slowly but noticeably flattened over a period of months? If so, you may have a condition termed Posterior Tibial Tendon Dysfunction or PTTD.
The posterior tibial muscle is the main muscle that supports the arch of the foot. The tendon runs on the inside of the leg right behind the inside of the ankle. It is the main muscle that allows you to turn the sole of one foot in so that it is facing the other foot. In certain foot types, this muscle can be subject to a significant amount of force, causing over lengthening and breakdown of the tendon. If the tendon degenerates or loses its strength, the muscle loses its ability to hold the arch up. With time, the arch slowly loses its height, causing pain and difficulty fitting in shoes. This process may not produce enough discomfort to push you to see a podiatrist until some irreversible damage has already been done. There are different stages of PTTD, thus the treatment depends on how degenerated the tendon is. In most cases, an MRI is needed to assess the current status of the tendon.
There are a couple tests that we can do in the office to assess if PTTD is present, and if so present, how far advanced the condition is. This helps to determine which conservative or surgical options may help. We’ll discuss these clinical tests in the next post.