There is a diference between magnetic fields produced by magnets and by electromagnetic devices. Basicaly the field from a magnet is static (to the magnet) and the electromagnetic device occilates. This has a dramatic effect on certain materials, and is also dependent on frequency.
If all those who think magnetic fields can have no effect on the Human Body would step foreward and place there heads into a microwave (safetys removed) whilst I switch on.......... what .... no voulenteers?
Obviously, microwaves are tuned to resonate with the water molecule produceing heat! Other devices MAY have other effects.
Until recently Wesern Medical Science denied that accupuncture works, dispite proveable evidence to the contery. Could the same not be true of magnetic therapy?