Ok if he is shedding he might got some skin stuck to his front legs, cutting out his circulation in that area, so you should keep bathing him if this is the problem.
Another cause could be that he got hurt and maybe broke a bone or a nerve.
Or something called metallic bone disease (mbd) is this is this case take him to the vet, and feed him lots of calcium.
If he does not get better in a week, you should seriously used about 30 dollars to take him to the vet.
GOOD LUCK !!!

Has there been any trauma recently? Any unusual stress? Have you noticed him twitching (as in having a seizure)?

Those are my best guesses as to cause. The first one means he may have broken or dislocated his legs, the second means he might have had a sort of nervous breakdown where his legs are temporarily disabled (not a usual thing), the third means he could have had nerve damage in some way and that's causing this. Either way, a veterinarian will be able to tell you what's wrong and will be the only one who can fix it.