Absorbing arch (internal)


When a “flat foot” is considered, usually it is defined as the decreasing of the air-gap (or clearance) under the inner part of the foot, namely under the Medial Longitudinal arch. But the fact of the matter is that unfortunately nobody connects the descending of this arch’s height with deformation of supporting external arch (Lateral Longitudinal). That is why biomedical and biomechanical solutions underlying design, construction and manufacturing technology of regular custom-made rigid orthotics, – they are not correct in principle.

The decreasing of air-gap under the internal arch may be rightly viewed as the result of heel-bone turning (valgus process) or as the consequence of pronation process for subtalar joint (i.e. when and where internal arch is supported by heel bone). Such is the kinematics of internal arch functioning, the main goal of which is to extinguish inertia forces born by movement itself. Turning of internal arch happens on the level of subtalar joint, and only after the appearance of support point under external arch. The emerging “rotation force momentum” is turning the arch inside.

It is important to distinguish the vertical depression (or amortizing) of external arch as well as of transversal arch from the turning of internal arch. The construction of orthotics must depend on such distinguishing. It is because external and transversal arches need to be considered as constantly working strings, as long as internal arch calls for turning (supinating) with respect to subtalar joint. It is absolutely not permissible to insert rigid support under internal arch, because this constitutes depriving it of possibility to extinguish by springing those inertia forces that are born by movement itself. It is worth pointing out that velocity of moving the leg ahead at moment of putting the foot down on support while making a step, is 60 km/hr. To extinguish such velocity the big air-gap is necessary, i.e. the braking track that secure possibility of exchanging stepping legs while walking.

The task of sustaining the human body in vertical position is the responsibility of transversal and external lateral longitudinal arches. They define as well as regulate the position of body’s General Centre of Gravity in the support plane along two coordinate axes (X-axis and Y-axis), thus bringing GCG to coincide with Centre of Gravity for support foot triangle. If for some reason GCG shifts along any of the axes, consequently the following takes place: overloading and deformation of respecting external or transversal arches, or pronation of internal arch. Up to 96% of its energy human organism spends to sustain the body in stable vertical position. If the feet arches are properly corrected, the energy load on Central Nervous System and on vestibular apparatus is decreasing.

Deformation of the feet arches could not be considered without interconnection with vertebral column or spine condition, as well as these considerations must not neglect the gait biomechanics, because otherwise the whole concept of feet correction and orthotics application becomes impaired. Frankly speaking, this is exactly the reason and the base for the fact that insoles named regular orthotics are in reality not the medical devices. Among the orthopedic specialists the understanding is absent of what exactly deformation is, and consequently the chosen methods of deformations elimination are impractical and not right. When orthopedic professionals make a statement that orthotics (they mean regular rigid custom-made orthotics produced from negative imprint) do not eliminate deformations, they demonstrate lack of biomechanics knowledge, as well as oblivion in compensating the load and in restoring the balance of forces in body’s skeletal-muscular carcass. There is yet another proof of these specialists incompetence – they are engaged in feet correction without considering the condition of vertebral column and all other skeletal structures.

The most substantial failure and therefore the most serious responsibility of promoters and providers of rigid orthotics is the following: they view as the “flat foot” the depression of internal arch’s height and they use rigid orthotics to lift it up. This procedure deprives the arch’s muscles of possibility to contract and therefore to perform the muscles’ pivotal blood-pumping function.

The contemporary estimation gives that 85% of population are not walking properly, and also are walking in the footware that is not correctly manufactured. The five-phased human gait that was physiologically and evolutionally conditioned, is at present transformed into one-phased gait. For this reason blood circulation of the whole human organism becomes distorted and deficient. There are a lot of consequences and complications to it – one, worth mentioning because of its frequency and scale, is the overwhelming increase in varicoses diseases (it is difficult to believe that veins’ surgical removing is viewed at present as the treatment). All in all, it looks like nowadays the process of feet correction is completely uprooted from real integrity of human body’s existence and functioning, and that absolutely each and every stage is abstracted from reality – beginning with diagnostics and finishing with manufacturing of orthotics and orthotic footware.

When you hear the doctor declaring that it is not recommended to provide the children up to the age of 5 years with orthotics, you may ask – and what about the joint formation in this case, more to it – what joints deterioration you expect to observe in middle age and farther on? We frequently observe the deformed toes at the age of 3 years now, and keeping in mind that toes muscles represent the most powerful group in the system of venous-muscles pump, we should consider the possible damage to the whole growing organism health and well-being.