I know this is waaaaaaay off topic but it was so cool i wanted to post it.
I went to visit my new chiropractor/A.R.T. practitioner in Chiswick this morning. He gave me a very thorough work-up, which included asking me if I had any body piercings. As it happens, I have (or had, until this morning) a navel piercing.
He then showed me something remarkable. I was lying on my back on the examination table. He asked me to raise my arm - he tried to push it back down to my side, and asked me to resist. The first time he tried to push it back down, I was easily able to resist. The second time he tried it, he put one finger on my piercing. Amazingly, this seemed to drain all the strength from my arm - he was able to push it back down to my side with no trouble at all.
What he'd done by touching the piercing was to 'complete a circuit', which had the effect of making me lose about half of the strength in my arm. Apparently, some people react very badly to metal in their bodies, particularly near major organs and muscle groups. It turns out that I'm one of those people
the piercing has been in there for about 10 years, but it came out as soon as i got home.