cam

Priscilla Ballou <vze23t8n@verizon.net> writes:

You're trying to do the wrong thing, which is to use your accurate
focussed vision to assess distance before you put your feet down. That
kind of vision is slow, and limits your speed if you use it. It's
appropriate when you're scared or untrusting, which you presumably
are. Your are, however, equipped with another much faster visual
system for assessing the distance of obstacles, footholds, etc., which
uses blurred peripheral vision, and relies on the optical flow
generated by your movement. The trick is you look ahead, in the
direction of travel, but throw your attention to the stairs *without*
shifting the distant centre of your gaze.

It's easier to get the hang of this in a non-dangerous situation such
as walking quickly through a crowd. The normal method is to look at
each person who is an obstacle, as you decide which way to go round
them, etc.. To practice the faster peripheral optic flow vision, stare
straight ahead into the distance, while detecting nearby obstacles
(people) and their trajectories with blurred peripheral vision
*without* looking at them. You shift your attention around without
shifting your gaze. It not only works surprisingly well, it works
*better* than shifting your gaze. But it takes courage to "let go" and
start learing to use it, and like cycling, it takes a bit of practice
to get the hang of it.

This is how racing car drivers avoid collisions. It's how soldiers run
through trees at night. Don Juan spent a lot of time trying to teach
Carlos Castaneda refinements of this method. It's part of our animal
heritage which lots of city dwellers have forgotten.

But it depend crucially on optical flow to assess distance accurately,
and you can't get the necessary flow unless you're moving fast
enough. If you're having to use the handrail you probably can't move
fast enough on stairs to make it work.

Don't be embarrased to use a walking stick. Especially on downhill
even the small fraction of weight a stick can take off a bad knee can
really help, and it also helps stability and removes some of the
awkward side and twisting forces of balance.

I know folk who who took up a stick (or poles for downhill walking in
the hills) because of bad knees, who've reported that not only did it
help, it helped enough that the bad knee started to heal, so that now
they need the stick *less* because of using it. When going down hill
or down stairs, bend your knees a bit more, so that less of the impact
shock goes straight through the knee joint. Sherpas will tell you that
white men knacker their knees by walking with their legs too straight,
a bad habit learned on flat floors.

Take your time choosing a stick. You probably won't know enough to choose the
good 2nd stick until experience with what is wrong with the first
stick educates you.
--
Chris Malcolm cam@infirmatics.ed.ac.uk +44 (0)131 651 3445 DoD #205
IPAB, Informatics, JCMB, King's Buildings, Edinburgh, EH9 3JZ, UK
[http://www.dai.ed.ac.uk/homes/cam/]