To be fair, if someone was in truly poor health or undergoing radical chemotherapy, standing at length would likely be either incredibly difficult or impossible.
So sure, it's not fool proof, but its also not a bad indication that reports of his impending demise are exaggerated.
When my dad eventually succumbed to cancer (technically kidney failure), it wasn't until the last couple of weeks or so that he had energy and weakness issues. Even a month before, he was still out and about. With chemo, he was only weak for the day of, and fine the next day. I wouldn't say Job's apparent health can give any clues as to his health, aside from the fact he has at least another month left.
