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Ed Keith said: "I get to the place when I stand up to walk I cannot pick =
up
my feet."
I would suggest that there are two components which contribute to problem=
s
of gait in PD.  One is a visual component and has to do with the improper=

perception or processing of low velocity apparent motion (optical flow) a=
nd
a second autonomic nervous system (ANS) component which tends to
pathologically augment the normally occurring tone in muscles to the poin=
t
of rigidity.  The vision mediated component is always present when there
are gait abnormalities and when PD worsens over the years the autonomic
nervous system (ANS) component becomes clinically apparent.  To test
oneself for the presence of the ANS component one need only get down on a=
ll
fours in the crawling  position.  The inability to take a step with one's=

arm suggests the presence of the ANS component.   This is because when th=
e
arm, like the leg, assumes a weight bearing posture it has postural tone.=
  =

This postural tone is augmented by the ANS system to the point of rigidit=
y
of the muscles and inhibits the lifting of the extremity to take a step. =


Ed Keith later says: "When I get going, I do alright untill I stop again.=
" =

If by some means we can initiate walking this rigidity diminishes because=

as the leg walks it alternately bears weight and then doesn't bear weight=

as it cycles through the stance and swing phase of gait.  The net result =
is
a decrease in postural tone and ANS rigidity. For the same reason
momentarily leaning against a wall can overcome a freeze.  Another better=

way to overcome this ANS induced rigidity is to use under arm crutches.  =

By bearing a significant amount of the body's weight under the arms, weig=
ht
(and thus background, postural tone) is reduced in the legs which in  tur=
n
reduces rigidity allowing one to lift the legs.

Tom Riess