Structural imbalances originate in the feet. If we do not address these imbalances, regardless of what other treatments or conditioning we use, whenever we are standing, our posture is imbalanced. This imbalance produces an abnormal mechanical loading on certain joints, tendons, and muscles, increases the likelihood of injury, and accelerates the breakdown or degeneration of parts of the body. Every human being has a unique structure, not only in their feet, but also in their entire neuro-musculoskeletal system. This is why it is important to understand the entire structure if we hope to attain optimal biomechanical alignment and function.
The third foot type is called underpronated or supinated, that is, high-arched. Again, this type appears in a smaller portion of the population, though for some reason it seems to be higher in the running community. The examiner’s fingers will fit easily under the medial arch, with room to spare. Because supinated feet are very taut and rigid, they are weak shock absorbers, which means the shock of hitting the ground is much greater through the lower body and up into the hips and low back with high-arched feet than with neutral or flat feet.
With all three foot types, we cannot test the lateral or transverse arch without a digital foot scan (see Figure 2) that shows the weight-bearing and dropped arches of both feet. The foot scan also shows the very unique personality of each foot. Once an arch has dropped, there is no way to get that arch to become strong again. In order to have that arch function properly, it needs support, as in a custom orthotics.
There are three arches in the foot (see Figure 1), all of which are critically important. The arches give the foot the necessary strength to support the body in the most balanced fashion. In most people, one or more arches on each foot have dropped. Most people also have an imbalance between their right and left feet. Even the slightest imbalance will trigger compensatory effects all the way up the structure. In addition, due to gravity, aging, and the incredible amount of stress we put on our feet during our lifetime, our arches fall over time. Because we’re typically one-side-dominant people and engage in both symmetrical and asymmetrical activities, it’s common for our arches to fall at different times in our lives, increasing the imbalance between our feet. This is why we recommend that all people be fitted with custom orthotics as early as possible in life. We begin patients at the age of seven, when their foot type becomes apparent.
It is my opinion that all individuals will do best with custom orthotics and neutral stability shoes. Using custom orthotics takes a lot of the guesswork out of the choice of a proper running shoe.
There are two different philosophies in the custom orthotics market. Many podiatrists and orthopedists put the foot in a non-weight bearing position, manually create an arch in the foot (this is called the sub-taler neutral position) then cast the foot. They then make a rigid or semi-rigid orthotic. This is generally done for foot problems, but not for biomechanical balancing up the kinetic chain of the human body.
The second philosophy is measuring the foot in the weight-bearing position on a digital scanner. This shows what the foot is doing under weight-bearing conditions. Measurements are then taken, after which a flexible custom orthotic is built that includes three arches and shock absorbing materials. This orthotic allows additional shock absorption and gives symmetrical support and the flexibility for full movement of the foot during the gait cycle. This is the type we use in our office, and I highly recommend them over the first option.
Flexible orthotics last about two years with normal wear and tear, though this may vary from person to person.
The actual digital scan (see Figure 3) shows the status of the three arches. When an arch weakens and has lost its ability to support, there is also a loss of proprioceptive acuity (neurological strength). Strong arches or external support is needed to give the body a symmetrical foundation, which is important for long term wear and tear of the structure.
Although we commonly say there are three different foot types, in actuality, there are six. There are three in the static, or standing position, and three more in the dynamic, or moving, position. The simplest approach when dealing with foot types is to get fitted for custom orthotics, which will basically neutralize feet so they will function normally.
The first foot type is the pronated, or flat, foot. This means that the medial arch (see Figure 1, A-C) has fallen below the normal level. We can determine this by an examination with the standing foot. When the foot is in motion, a trained eye can often detect improper foot take-off and landing. Over-pronation (an exaggerated form of flat feet) makes the foot roll in excessively on toe-off and sends increased stresses up the kinetic chain that can lead to injuries above the foot, i.e., in the ankle, knee, hip, or low back.