Part of the show Superconductivity and Cooling Devices
Dave in Northampton asked:
How do magnets work when they're used to treat injuries such as a frozen shoulder?
I'm not sure that they do actually. I have some experience of this when I twisted my knee playing football. Someone told me that if I taped magnets around my knee then it would help it heal up. The problem was that when I walked up to the window, my knee stuck to the radiator beneath it and that didn't help my knee get any better at all! There was a study written up in the British Medical Journal a few years ago in which people looked at this question. They said that people did seem to do better with these bracelets and things, but there's no scientific reason of justifiable reason for why people should get better. What they suspected was that the trail was a bit biased. How you do this kind of trial? You give people with achy knees either a magnetic bracelet or a non-magnetic bracelet. Now it's pretty easy for people to work out whether they've got the magnetised version or the non-magnetised version. If people are given one and they think that it's a placebo, then they're probably going to claim that it works less well than if someone has a bracelet that is obviously magnetic because it sticks to stuff.