@Zardoz,
In my considered nonmedical opinion, I wonder if he has lymphedema. I'm suggesting this because my mother had it. IIRC, it was either a side effect of chemo or from the Hodgkin's Lymphoma she battled for the last 20 years of her life.
My mother had it in both legs and the arm with the nondominant hand. It was bad enough that it affected her ability to walk (her legs were heavy) and she couldn't wear her wedding ring any longer.
If this is what Trump has, it could be part of the explanation for why he doesn't walk much and often seems to be pitched forward. With the hand, who knows? It's apparently his dominant hand (Wikipedia doesn't list him as being a lefty).
Could also be due to some sort of intravenous treatment. And keep in mind that, in all fairness, he's older and your skin gets thinner so you bruise more. This happens with my father.
In any event, it's obvious there is something going on with Trump's health. Given how opaque this administration is with that sort of information, it should be concerning.