Luthier,

If your loss of motor function is following a lot use and is accompanied by a lot of swelling my inclination is to think nerves have pressure on them and aren't as responsive. It doesn't take a lot of pressure to impact nerve impulses.

If you don't already use any light compression with activity it could be worth a try to avert some of the swelling. I find the socks uncomfortable for my situation so sometimes use athletic calf sleeves. I prefer the Zensah, as they are super soft and not too tight.