He stepped forward with one foot then dragged the other foot to meet it. Then he took another step forward and dragged a foot forward. He did not stride down that ramp as an ordinary person would. He did it with great difficulty hesitatingly slowly oddly. I think it was due to some possible neurological disease. I read that he has always had trouble with steps and ramps going down them. Why? I don't and I'm 8 years older than he is and I'm certainly not athletic. Something is going on physically with him which is also why he sometimes slurs his words and stumbles verbally. Short-circuit in the brain? Snapses not firing sequentially? I don't know but it is not normal. Even though I dislike the man whatever he is going through does not make me happy. I feel sad as a matter of fact.
He was merely counting his steps so that he could brag about it later. (“I took SO many steps down that ramp. It was the most steps that any president has ever taken down a ramp.”)
To be serious – I too think he has some neurological issues. It’s possible he had a TIA or two. Did you see the 2 handed drink of water thing he did? The way he slurs words when he talks is also a sign of issues (again a possible TIA). His egotism will never allow him to admit it, but he is definitely having serious problems.