Thanks eeefarm. When I picked him up from the shelter I was told that he has a nerve damage in the fight front-leg resulting from a brain damage acquired from a car accident. As a result of that he is limping (the leg is basically paralyzed). It is not painful and doesn't seem to bother him at the moment, although he gets tired during long walks.
I've been to three vets who have said there is nothing to do (except for possible amputation which I think is unnecessary). I nonetheless wonder if you have any tips on if there is anything one could place on the leg to support it?