in reply to @bennettrory I have a similar problem, and for which I am seeing a back surgeon this coming week to find out if the tarlov cysts that have come back after having them removed years ago, is the cause for this 'new' sensation of weakness I often get now in both legs. While I am walking 3-5 miles per day, frequently in the evening, I find that my legs feel weak, not from walking. I hope that potentially having back surgery again will alleviate the issue. I did not see you mention anything about what I have, and I wonder if you have any kind of diagnostic studies, other than nerve studies, that might explain your issue