Got Flat Feet?

I have looked, but cannot find out how many men were not drafted into the military because of “flat feet.” What is so bad about flat feet? The answer is, as you probably guessed it … “well, it depends.”

To be clear, there are other foot conditions that may be sufficiently detrimental to disqualify one from a high level of demanding physical activity, such as military training. And, certainly, there are many “flat feet” marching around the military these days.

It is useful to think of flat feet in two categories: Fixed or Rigid Flatfoot, and Flexible Flatfoot.


Just as it describes: A foot that has a visible arch with no weight, but that flattens out very noticeably with weight. The arch will be noted again when asked to stand “on the toes.” This change in the arch implies that the arch structure is not inherently rigid or stable with weight on it.


NO. But flat feet are more likely to be problematic. Here’s why. A flexible arch depends more on the action of muscles to change the position of bones in the arches to allow for the foot to push off of the toes, such as in walking, running, or jumping. Therefore, a flexible flatfoot is, at least in theory, (and I would say more often the case), more likely to develop painful problems with increasingly vigorous and sustained activity. This is because it is more demanding on muscles, tendons, and ligaments to work with a more flexible/floppy arch than a more rigid and stable arch.

The good news is that a flexible flat foot can be more easily manipulated into a more stable position with interventions such as strengthening exercises, arch supports, and certain shoes, and thereby improve performance.

Broken twisted ankle - running sport injury. Female runner touching foot in pain due to sprained ankle.


A foot that is stuck in a flat position, with multiple causes.

  • A congenital abnormality in certain joints, present from birth, such as a “tarsal coalition.” This problem typically manifests in pre-adolescence/ adolescence. Treatment depends on the extent
  • Acquired later in life due to incremental damage to supporting structures of the arch. Even a flexible flatfoot in childhood may become increasingly adapted to the flattened position and “get stuck” in a flat position. This situation may arise from an overly tight calf muscle.
  • Adult Acquired Flatfoot. Usually seen in 50s and beyond, and most common in post-menopause. The arch gradually lowers and the foot/ankle starts to hurt. The rest of the foot seems to move “outward.”
  • Causes: A gradual weakening of muscles supporting the foot and leg due to disuse.
  • Possible hormonal link, such as with pregnancy, though this seldom results in a permanent and painful flatfoot condition.
  • Inflammatory disease such as poorly controlled rheumatoid arthritis.
  • Age: the arch tends to lower gradually


  • A tight calf muscle may play an important role in the development of a flatfoot, or in making it hurt more.
  • A painful flexible flatfoot may become more fixed and rigid over time.
  • Flat feet can be an important contributing factor to other problems such as crooked toes, bunions, pain in the ankles, lower legs, knees, hips, and back.
  • Some shoes may look like they have an arch support in them, but most shoes merely have a flexible cushion that curves at the arch and completely flattens out when standing on it. The actual last (bottom platform) inside the shoe is always flat.


Indeed they can – BUT not just any arch support for any flat foot. Sometimes an inexpensive, generic, off-the-shelf device may be adequately helpful. Realize that in general, you get what you pay for. A pre-made arch support may also be modified to a certain extent to make it more customized to a particular foot. A custom molded arch support (foot orthosis) may be necessary. These are typically covered by insurance. Prices can vary widely from place to place. The features made into the foot orthosis can also vary widely based on the specific needs of the foot, not unlike a specific corrective prescription for eye glasses.


Indeed it can. The type of surgery depends on many factors and is beyond the scope of this article.

In summary, having flat feet may or may not be a problem. Whether or not there is a problem depends on multiple factors. You can research flat feet with “Dr. Google” but there is no substitute for a hands-on, eyes-on evaluation, especially if your feet do give you constant trouble.

flatfoot reconstruction 2
flatfoot reconstruction 3

Compare right foot after surgery to correct flatfoot and left foot without corrective operation. The left big toe is less straight and more likely to develop a bunion. The left arch is sagging more toward the floor. Also notice on the front inside of the left ankle there is a tendon (the bulging line seen connecting the ankle to the foot) that is visible through the skin. This tendon is trying to pull up on the arch of the left foot to stabilize it. This is one example of how muscles have to work harder to support an unstable flat foot and become sore.

Example of adult acquired flatfeet. As time passes, the deformity tends to get worse and more rigid, making effective treatment options fewer and more complicated. Earlier treatment can prevent some or all of the problem from worsening.

pes plano valgus 2