to grandmael - I have sensory motor polyneuropathy and I also wear foot braces for bi-lateral drop foot. In 4 years, I've seen only one person wear what I have. My PN started first, then drop foot a few years later and one day, the drop foot came on one afternoon, The slap of left foot came literally out of nowhere. Six months later, the other foot. I have bad knees as well, but orthopedic surgeon will not replace due to fear that if I have a fall and land on knees, could be a serious real problem. Back issues L-3 to S-1. Orthopedic docs tell me PN is not from knees and not from back based on MRI. Neurologists tend to lean in one direction as to "possible causes" while orthopedic doctors normally don't agree. Leaves one scratching their head. Lots of guess work involved, unfortunately, many times no cause is the end result. Just don't know I've heard more than once. Best to you on your journey.