If we pass a sheet of paper underneath an usual shoe, we verify that the sheet of paper usually advances up to a 1/3 of the foot. The big toe being the guiding toe for the standing and walking positions, this means the big toe is completely deprived of its proprioceptive function.
Proprioceptive shoes must respect this physiological condition.
We are building proprioceptive shoes according to this condition.
Wrong proprioception leads to back pain, unbalance, cognitive disturbances including dyslexia and to the other symptoms of Postural Deficiency Syndrome (PDS).
To correct the symptoms of this syndrome, we need appropriate shoes among other techniques for treatment. These shoes are also required for prevention, not just for treating.
Inappropriate shoes could be a factor of aggression to the proprioceptive system and be harmful to human health.