Over the next couple of weeks I would like to discuss the nature of painful flat feet in the older child/teen and adult, and share some of my thoughts on treatment of this foot deformity. Since this is a fairly involved topic, splitting the discussion up will help keep the post from getting too ‘wordy‘.
To start with, I would like to explain why we use the word ‘deformity’ to describe flat feet. Flat feet are simply a normal anatomic variation of the human foot, as much as ‘normal’ or ‘high’ arches are. It is likely mostly genetic, and passed to our children. This variation is quite common, but does pose a unique challenge to modern humans, who tend to wear shoes most of their lives to protect the foot skin from the dangers of civilized living. In populations where shoes are not worn, the foot’s muscle and support system is usually able to adapt to this flat structure from an early age. By wearing shoes, we take away some of this adaptation. However, the danger to the foot by walking barefoot in public or on concrete, gravel, and other hard surfaces far outweighs the lack of structural adaptation, and the notion that one should walk barefoot to keep this ‘natural’ process active is potentially harmful. Unfortunately, because of the infrastructure we have paved our ground with for thousands of years, we are far better off in shoes. However, those of us with flat feet must now deal with the issues that come with an unadjusted foot structure. Even though flat feet are not a deformity in the same vein as an extra toe or clubfoot, we still refer to it as a deformity because in essence it functions as a foot deformity by being the source of numerous foot problems over time.
The foot problems that develop due to flat feet are generally due to instability that is present in the foot when it is allowed to over flatten. This instability will gradually cause numerous other actual foot deformities by forcing the foot’s muscle and support system to change the way it anatomically is supposed to function. The change in the way certain muscles and tendons pull on the foot, and the change in how ligaments and joints are positioned, will often lead to foot deformities like bunions and hammertoes. These deformities in and of themselves can become painful over time in certain people. However, of more importance to this discussion is the role flat feet play in causing tissue injury, which leads to chronic pain. When flat feet are subjected to lengthy or strenuous activity, the overly flexible nature of this foot type can allow other parts of the foot to become overly stretched and strained. This includes the plantar fascia, a thick cord on the bottom of the foot that is the source of the common heel pain when it is injured, as well as a large tendon under the inner side of the ankle called the posterior tibial tendon. When this tendon is injured and not treated properly, it can lead to a debilitating degenerative process that can actually allow the foot to flatten further. Other injuries directly related to flat feet include nerve inflammation in between the long bones of the foot known as a neuronal, as well as various arthritic conditions.
Since we now understand how and why feet are flat in some people, as well as what problems they can cause, we should move on to what is typically done to treat this condition so that it does not lead to pain and suffering. This can be done by modifying the foot structure externally (better shoes and orthotics inserts), or by physically changing the internal structure of the foot (reconstructive surgery). On the next couple of posts, I will discuss the reasoning behind each approach, and what I feel is the appropriate situation for either external or surgical treatment.