Inserts may help flattened feet

By Dr. Lou Pack

“What could have caused my husband to suddenly develop a flattened foot?”

Despite what many people think, a foot that flattens is not something that should be taken lightly. Think of your foot as a series of stacked bones; i.e., like bricks on a wall, supporting the structures above it. When all the bricks are in place, the wall is straight and the structures above remain stable, secure, and stress free.

But when a foot flattens, the bones slide off each other (again, like bricks sliding off a wall), in essence dislocating. It’s this dislocating force that destroys cartilage and causes subsequent degenerative arthritic changes. That’s why it’s often more important to evaluate just how much a foot flattens (from sitting to standing) rather than how flat it is. When these destructive changes occur, they do so not only in the bones of the foot, but in all of the weight bearing joints of the ankles, knees, hips and back, which the feet support.

In most instances flat feet are inherited and easily treated with inserts of various types. But the sudden onset of a flattened foot is totally different. Usually, this is due to a rupture of the posterior tibial tendon; the major tendon that runs along the inside of your leg, attaching just above your arch, that counteracts the forces of pronation or a flattening of the foot.

Like stress fractures, tendon ruptures can occur without any noticeable injury. Certain medical conditions such as rheumatoid arthritis and cortisone injections can precipitate this. Most often, after many years of excessive stretching, severely flattened feet can cause enough stress on the posterior tibial tendon to cause it to tear away from its attachments.

Pain along the inside of the arch, and toward the ankle and top of the foot can at times be disabling. Surgical correction is often recommended but is very involved.

Splinting the foot in its ideal position often allows the tendon to heal without surgery. Although there may always be some tendon weakness and foot dysfunction, with precise support (custom foot inserts) normal activity can usually be resumed.

Prevention is simply accomplished by having your feet evaluated and if necessary, preventing excessive flattening of the foot with inserts as mentioned above.

Such treatment can not only prevent serious conditions like this, but will (to some extent) protect your other weight bearing joints from osteoarthritis. And, as a side effect, by optimally controlling foot position, your performance in sports may very well improve too!