Posturology as a Treatment: Intrinsic Foot
Muscles Instead of Rigid Orthotics?
Nigg concluded that medial arch supports, placed in the rear part of the
arch against the calcaneus, reduces the initial pronation, but placed more
forward to the midfoot, the effect became much less. Still compared to
barefoot running, he found more pronation when wearing shoes.
Shoes. Nigg concluded that medial arch supports, placed in the
rear part of the arch against the calcaneus, reduces the initial
pronation, but placed more forward to the midfoot, the effect
became much less. Still compared to barefoot running, he
found more pronation when wearing shoes.
Neurologic of the Plantar Foot
The hairless skin of the foot sole has a great number and variety
of neuro-receptors: Ruffini, Krause, Vater, Pacini, Meisner, free
nerve endings, etc. They all have special functions, but many
of them are also sensitive to pressure. We call them mechanoor baroreceptors. Kennedy et al identified a total of 104
mechanoreceptors in the hairless skin of the foot sole, active
only when the foot was loaded. Yet, when the foot is in an
unloaded position no discharge activity in any of the cutaneous
receptors was found, especially in the absence of intentionally
applied stimulation. These findings suggest that skin receptors
of the foot sole behave differently from those receptors found
on the hairless skin of the hand. This may reflect the role of
foot sole skin receptors in standing balance and movement
control.
René Jaques Bourdiol, has published extensively about his
theory, however only in French, and unfortunately, not meeting
scientific standards of the scientific community. His most
important book, Pied et Statique, hypothesises that a (cork)
insert, 1 to 2 mm thin, placed under (for example) the medial
arch, has a direct effect on the intrafusal nuclear chain and the
bag spindle of the m.abductor hallucis. He called his therapy
‘proprioceptive’.
In his opinion, the sensitivity of these γ-fibers increases to more
sensitiveness of the 1-a afferent nerve. This then leads to a
contraction of the m. abductor hallucis activated through the
α – motor neuron at spine level. These nuclear bag and chain
spindles are found within and parallel to the muscle fibers and
are sensitive to stretching. Since 1978 this technique, known
as podopostural therapy, has been successfully applied in more
European countries.
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Pedorthic Footcare Association www.pedorthics.org
Observations
When we consider the thickness of dermis and epidermis,
plus an average tissue thickness of 1 cm under the foot, I can
see why scientists are skeptical that a 1 to 2 mm thin piece of
cork changes the position of the foot and consequently the
posture, in spite of the empirical results. In my opinion, the
only sensors that can be activated directly are therefore the
mechanoreceptor