Flat shoes increase neurogenesis
Introduction
Vestibular receptors sense the orientation of the head relative to gravity and produce representations of the vertical and horizontal in the vestibular nuclei continuously integrated with signals from muscles, joints, skin, and eye. These representations are used by vestibulo-ocular and vestibulo-spinal reflex pathways, and by cortical sensory projections. The vestibulo-ocular reflexes are slower in humans, 7 ms, than in for example monkeys, 5–6 ms, [1] although they should be equal. These slow reflexes also influence for instance balance through vestibulo-spinal reflex pathways. Human standing posture is maintained through a central postural programme assisted by various types of sensory feedback that together contribute to postural stabilization as well as being the basis of a body posture representation. The field of gravity has shaped anatomy and the body scheme from which is established the central motor program that controls the maintenance of a given posture. [2] Humans have gone barefoot or used footwear without heels for some 5 million years. In the western world heeled shoes have only been used for the last 400 years. Possibly this could mean that there have been changes to postural stabilization.
The mobile larval form of the sea squirt possesses a central ganglion, but this ganglion disappears in the stationary adult form. Llinás [3] suggests that the nervous system evolved because it is useful to creatures that move about in the environment. A central location that integrates various sensations allows the mobile creature to predict what effect certain motions will have, and this adds greatly to survivability. Neurogenesis is involved in this process; could the use of flat footwear give a better postural stabilization through improved neurogenesis?
Section snippets
The hypothesis
The hypothesis is that Flat shoes increase neurogenesis. According to current thinking the use of heeled shoes is normality and the relationship to neurogenesis is not known. The hypothesis evolved because of pains with flat feet and trying to improve it by using flat shoes. When this happened, it would probably depend on the function of the brain. I then wrote “Is there an association between the use of heeled footwear and schizophrenia?” and thought that neurogenesis would be important. The
Results
Kavounoudias et al. [4] writes that “One can expect that tactile inputs from the main foot supporting areas tell the central nervous system continuously and precisely how the mechanical pressures are spatially and sequentially distributed on the skin.” Lackner and DiZio [5] express this as “receptors in the soles of the feet provide a mapping of body orientation to the upright.” Mittelstaedt’s idiotropic tendency [6], of unknown, probably central nervous origin, localizes it in or close to the
Discussion
When going barefoot or using flat shoes without elevation of the heel the weight is always on the level. Using heeled shoes the foot is in a forward inclination and then, when the weight is on the forefoot, on the level. The representation of the horizontal is turned into a forward inclination, and sensory signals then produce a false representation of the horizontal instead of the truthful one. Flat shoes without elevation of the heel indicates the same orientation of the body mass.
The sensory
References (16)
Physical activity, eccentric contractions of plantar flexors, and neurogenesis: Therapeutic potential of flat shoes in psychiatric and neurological disorders
Med Hypotheses
(2009)- et al.
Brain functional activity during gait in normal subjects: a SPECT study
Neurosci Lett
(1997) - et al.
GABAergic excitation promotes neuronal differentiation in adult hippocampal progenitor cells
Neuron
(2005) - et al.
Effects of environmental enrichment and physical activity on neurogenesis in transgenic PS1/APP mice
Brain Res
(2009) - et al.
Vestibuloocular reflex dynamics during high frequency and high acceleration rotations of the head-on-body in rhesus monkey
J Neurophysiol
(2002) - et al.
Adaptation of postural control to weightlessness
Exp Brain Res
(1984) I of the vortex – from neurons to self
(2002)- et al.
The plantar sole is a “dynamometric map” for human balance control
NeuroReport
(1998)