The Science behind the Kinetic Technology™

ProKinetics® Insoles - The Simple Solution to a Complicated Problem

People who walk barefoot on dirt do not share our western lifestyle pain problems.

If you have read the where and why you hurt pages, you already understand the connection between your feet and your posture and your posture and body pain. So, what is it about the feet that causes this problem? We could blame it all on the feet like the foot doctors do, but it’s not purely a foot problem. It’s partially an environmental problem that makes our feet incompatible with the flat world we have created. The reason ProKinetics® Insoles work so well is that they correct the root cause of the problem. They help your feet deal with their unnatural environment.

In our world of convenience and ease, as far as our feet are concerned, the world is flat.  We have made nearly every surface we stand and walk on flat. That includes the inside of your shoes, and that’s the problem because as you may have heard, people who walk barefoot in nature all the time do not share our typical foot and body pain problems.

The Cause of Overpronation

Elevated First Metatarsal

Hyper pronation (the arch flattening and the ankles rolling in) is consistently being blamed on "fallen arches". If this is true, fixing the problem would be as simple as providing arch support to prevent the arch from collapsing. Arch supports fix the problem while standing still (static fix), but as soon as the heel lifts off the ground, the foot goes into hyper pronation (dynamic failure).

Medical publications describe how the first metatarsal, in normal subjects, dorsiflexes (elevates) through 88% of the contact gait cycle (heel strike to toe-off) causing the foot to hyper pronate. The foot hyper pronates because the first metatarsal and big toe do not support the foot as it needs in order to be stable.

Dr. Dudley Morton, who defined Morton's Foot Syndrome, claimed the first metatarsal was hypermobile, meaning that the ligaments of the bones forming the medial arch are lax causing hypermobility. That begs a perfectly reasonable question: Why would only those few ligaments be lengthened and none other in the whole body. It seems people who are hypermobile - often dubbed double jointed, have extreme mobility throughout their bodies. Not only in their feet, and much less one toe only.

A more plausible and documented reason...

Referring to the model above, the first metatarsal connects through two bones, the Coniform and the Navicular to the head of the Talus (anklebone). It has been documented in cadaver studies that the rotational angle, in the frontal plane, of the head of the talus can vary as much as 20 degrees from one person to another. Since the head of the talus forms the basis for the first ray, the first metatarsal and big toe, it impacts its position. The first two illustrations demonstrate the change of Talus head angle and position of the first metatarsal.

When the weight shifts to the forefoot, the first metatarsal and big toe will still reach the ground, but because of the relationship between the position of the first metatarsal and the head of the Talus, the whole foot is caused to tilt inward (hyper pronation).

This position of the head of the Talus would bring the first metatarsal down to the ground and balance the forefoot so that every time you bend your knees, they would naturally travel right over the middle of your feet.  Unfortunately, most people have a foot structure where the head of the talus is flatter angle (next figure), and that causes the first metatarsal to lift up, so when you bend your knees, they try to move inward unless you force them outward by using your calf muscles. 

When the angle of the head of the Talus is flatter, the first metatarsal is not naturally weight bearing, and when walking on flat surfaces this problem is exaggerated. Even with arch supports, as soon as the heel lifts off the ground, the arch will naturally drop as the first metatarsal moves toward the ground.  You can actually feel the lack of ground contact, and if it is severe, see this elevation if you do a knee bend and force your knees to travel straight forward over the middle of your feet.  

So, from a structural perspective, this becomes the result.  As the first metatarsal ultimately comes down, the arch appears to collapse and the ankle and heel tilts inward (hyper pronates). You can demonstrate this by relaxing your calf and hip muscles allowing your legs to follow your foot structure.  Most people, around 60%, tighten their calf and hip muscles to control their ankles so they appear to pronate less, but doing this habitually causes fatigue and muscle pain, often in addition to foot pain.

Muscle Compensation - Attempted Supination

The Tibialis Anterior is overworked trying to prevent the inside of the foot from collapsing.

For most people, hyper pronation, walking knock-kneed with your feet pointing out does not feel natural or comfortable. The unnatural twisting and bending sends pain signals to the brain, and as the brain always does, it tries to avoid discomfort by correcting the motion. 

Muscles in the calves are signaled to avoid the inward collapse by tightening up.  Subconsciously some people try to shift weight to the outside of their feet - Supinate.  The unfortunate part of this muscle bracing action is that it is often excessive and causes severe overuse problems as well as instability.

This muscular bracing against hyper pronation illustrates that the body attempts to compensate for unnatural motion similar to righting itself when balance is lost. As you know, when you lose balance, your muscles tend to over correct, you become more rigid and are actually at higher risk for falling.

Proprioception

Proprioception:

Sensory signals are processed by the brain into motor (muscle) action.

A normally functioning body relies on proprioception. The body senses its position, velocity and tension. The feet play a pivotal role in your upright posture and balance.

What happens if the signals are missing or distorted? Diabetic neuropathy (loss of feeling in the feet) changes gait, and posture, weakens muscles and increases the risk of falls and foot injury.

When the first metatarsal is elevated, the first metatarsal isn't loaded until very late in the weight bearing cycle - after the heel lifts, and this deprives the brain of the signals it needs to establish balance and posture. The signals the brain relies on to control your feet and gait are arriving late or in some cases are lost completely. According to some studies, the first metatarsal and big toe do not significantly participate in weight bearing and propulsion until the last 12% of the contact gait cycle. By that time your mechanics and posture is completely distorted.

ProKinetics® Insoles restore the Proprioceptive Signals

By placing The Kinetic Technology™ wedge underneath the first metatarsal and big toe, the late or missing signals are restored by changing the timing of the first metatarsal ground contact. Unstable feet become stable so the natural proprioceptive signals can improve posture and body mechanics.