OK so I'm thinking of hiring a TENS machine. I know people have mixed opinions on them - some people think they're eternal salvation and others a waste of space - so I figured it's worth a try.
However, there seems to be a bewildering array for hire online. Are there any particular functions or features that are worth it? Is it worth paying more for the more expensive machines - what are you getting for the extra money? Which functions are a waste of time/money?
Or should I just shop around for the cheapest machine I can find?