On Fri, 13 Jul 2012 04:44:31 -0700 (PDT), jgharston
wrote:

My knees have already crapped out and I'm in my mid-40s. Light
switches I can do. Sockets and underfloor wiring leaves me
in agony.

Same here - ****ing sore.
I've been using my electric bike for a while; the other day I got on
it and pedalled the first couple of hundred yards with no power -
****ing Nora, the pain in the knees.
Funnily enough, when I've been using the motor and assisting it with
my own power, it's no problem after the first couple of miles to give
it laldy, not a twinge then. It's that first flexing motion that kills
me.