How does walking benefit OA knees?

Quoted message said:

I know knee pain has been done to death here, but does anyone have any
evidence that walking can improve Osteo Arthritis in the knees?
(Patellar or Femoral) The advice used to be that cartilage didn't
recover and so perhaps rest was the best approach.

Quoted message said:

Is there any research evidence that cartilage regenerates with exercise
please?

There is some disputed evidence that exercise plus appropriate diet
plus patience and determination may regenerate cartilage where the
problem is not inflammatory. Taking glucosamine may help too.

Speculating in general terms I'd say the problem is being miscast when
it is seen as a problem of wearing down which requires regeneration to
repair, even though that is how many doctors talk. Like all bodily
tissues, including bone, cartilage is constantly being destroyed and
constantly being renewed. What appears to be a static quantity is the
equilibrium state between degeneration and regeneration. When it
shrinks the problem is that degeneration has started to outpace
regeneration. So the solution is either to slow down degeneration or
accelerate regeneration.

I've heard of enough obsessive athletic types who ended up with bad
joint pains, were told by all the specialists they could find that
they'd worn out the joint and that it was permanently totally
knackered, and then went on equally obsessive and determined recovery
programmes which took a few to several years, but which worked, to
suggest to me that doctors tend to make predictions based on what
would happen to the average couch potato, and can often be surprised
by what intelligent and determined and probably lucky people can
achieve.

I have mild arthtitic degeneration in my left hip, which I'm told is
normal wear and tear for my age and the only thing to do is to wait
until it gets bad enough to require replacement. It hurts after
walking a few miles. But I've noticed that the more I walk a few
miles, the further I can walk before it starts hurting. Taking
glucosamine and fish oil both independently reduce the pain, and
together reduce it more.

I've read that a build up of lactic acid in the blood stimulates
cartilage regeneration in general. If so, the trick would seem to be
to take lots of exhausting exercise which involves the affected joint
as little as possible.

A common caveat is that if inflammation is involved, then it must be
rested until the inflammation subsides, else exercise is damaging. In
the case of cartilage and tendons the rest required to calm
inflammation can be several months. How do you know how long to wait?
If it hurts when you use it you haven't waited long enough :-) I find
that viewpoint plausible, since it matches experiences I've had with a
damaged back and a damaged thumb.

In sum I would say I think it's possible, but difficult, and may
require good luck as well as everything else you can bring to bear.

Just speculating :-)

--
Chris Malcolm [email hidden] +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/]