They have been damaged one way or another, possibly from fighting a Bonewalker or something, or from a disease.
You can restore those with spells, potions, or by going to a temple/imperial cult shrine.
I don't remember any items that drained those stats by wearing them. There was that one sword, Fury or something, but I don't think it drained all those attributes, and I can't remember any other items that might have done it. So I think those stats must have been damaged one way or other.