Flat Feet Explained: Part 2 Non-Surgical Treatment

flat foot

This week, I am continuing my discussion on the treatment of flat feet in teens and adults. We are now ready to discuss treatment options. In basic terms, there are two options for treatment, as there are two basic types of flat feet.  The options are supportive shoes and prescription orthotics inserts, and surgical reconstruction.  The two basic types of flat feet are flexible and rigid.  Flexible flat feet (which are most common), can be pushed and held out of a flat position.  Rigid flat feet are stuck in that position, due primarily to inflexibility of a deformity that is mostly bone in nature.  Today I will discuss shoes and inserts, which are primarily helpful for most cases of flexible flat feet (but not rigid flat feet).

Over the last fifty to sixty years, our understanding of how the foot functions mechanically has grown significantly.  The mechanics of the foot are complex, and not easily measurable by direct means given the complexity with which the various joints work together to push us forward.  Our current understanding of this function is advanced, but not perfect.  Regardless, the development of the field of foot biomechanics has led to the development of the prescription functional orthotic, a device that has made it possible for countless people to enjoy their lives foot pain-free, or at least with considerably less pain.  This device is not the same as over-the-counter arch supports found in stores and TV commercials nationwide, and it is not the same as pricy off-the-shelf plastic inserts masquerading as ‘orthotics’ in numerous national retail chains.  A prescription functional orthotic is a medical device that is made of a plaster mold or 3D laser scan of the foot.  This mold or scan is created while the foot is being stabilized in a mechanically neutral position, otherwise known as the subtalar joint neutral position.  In this position, the foot is neither in a flat orientation, nor a high arch orientation.  It is roughly a position that research has determined should be the model resting position of the foot, when the foot has stopped rotating inward or outward during the walking cycle.  Many different factors contribute to getting the foot in this position, as the foot has numerous ways of compensating for any variation in structure between one part of the foot and another.  A true functional orthotic takes into account these variations, and subtle ways of angling or shaping the insert arise in the prescription process that make the resulting orthotics function even better.  Because these inserts are constructed based on the specific foot mold or scan, and slightly altered based on a complete biomechanical exam of the foot and lower leg, they will actually correct abnormal foot structure in a predictable way.  Over-the-counter inserts simply shove wads of padding or plastic into the arch blindly and hope it will be close enough to give proper support to the foot.  These kinds of inserts are usually comfortable, and do provide more arch support that a shoe alone can give.  However, they do not provide the exact level of foot structure control that a condition like flat feet often requires. Only prescription orthotics can fill this role completely.

The use of prescription orthotics allows for stabilization of the flexible flat foot when worn from shoe to shoe.  This device reduces much of the strain the bottom of a flat foot endures with standing and walking, and it can indirectly slow down the progression of flat feet related deformities, like bunions and hammertoes, by correcting the underlying cause.  The proper choice of shoe also contributes greatly to this treatment.  In general, people with flexible flat feet need a shoe constructed with that foot structure in mind.  A better choice of shoe is one that is only flexible at the ball (front) of the foot, and not in the middle of the foot. It should have a stiff sole, a stiff area that cradles the heel, and should be wide enough that the sides are not tight against the foot when it widens out as it flattens.  Most importantly, it should fit the orthotic and be comfortable to wear after many hours of activity.

For the vast majority of people with flat feet, a prescription orthotic and supportive shoe will be sufficient treatment, much like eyeglasses or contacts are sufficient for those with vision impairment. However, those that have rigidly flattened feet are not generally helped by orthotics, as the foot must be flexible for the orthotic to change foot structure.  There are also times with flexible flat feet in which orthotics do not provide enough support to control pain symptoms.  In these cases, the physical structure of the foot needs to be permanently changed to relieve pain and improve foot function.  Next post, we will discuss surgery to treat flat feet, and some of the advantages and pitfalls of that approach.

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Flat Feet Explained: Part One

flat foot

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.