Regarding the video of Obama's speech in Belgium in 2014.
I've been thinking about the fact we don't see him wave with his left arm. The camera cuts away. In the beginning of the video Obama gestures quite normally but by the end he is quite still. Could he be ill? In 2016 at a press conference with Raul Castro Obama's left arm appeared limp when Castro tried to lift it up. This was brushed away as Obama wanting to avoid giving Castro a decent PR opportunity.
https://mashable.com/2016/03/21/obama-limp-wrist-cuba/