I think he has great problems in even walking around. That would explain the segway use. There are problems there with knees, hips or something that is impairing his mobility.
I would imagine at some point the segway became useful to Bush Sr. but he and his family were promoting it back as early as 2005 and you’d be seeing him and Barbara and even G W Bush riding around Kennebunkport with them. I believe it started as a recreational tool for Bush Sr. As you remember, he was a very active man even during his early use of the segway. Now I’m not claiming it caused all of his problems with his hip etc but when you stop using certain muscles and parts of the body one can start to slow down. At some point and at his age it’s bound to happen sooner or later anyways.
I’m sure as time went by the segway became more helpful for the elder Bush to get around. He is up there in age.
I just can’t help wonder how much it may have hastened his slowing down by using it as much as he did in the early part of his golden years.
May God bless him and his recovery.