i bought my wife these duo loops for a few years now and to be honest only have tried this myself for the past year and it has really helped with my knees and back. I recently asked my mother who suffers with arthritis to try my duo loop for a couple of weeks just to see if it makes any difference and the result was brilliant as about after a week she can now walk most days without her walking stick and also when in bed her back is not as sore. i am now trying to convince my dad to try it as well.