my father has paralysis in his left leg is in pain?
in my opinion he has intermittent claudications he can try circulatory exercise in the form of beurgers exercise ( elevate leg do ankle pump 15 times if he can then drop it for 15 seconds ) or he can go for medical treatment like lyrica or gabapentin. however i recommend investigation if he has a back problem (disc or spondylitis ) also a dopplar to make sure there is no thrombosis good luck