>>15393It's a replacement for a cane.
It provides extra support so you can walk on your own two legs, even if you're impaired.
Not trying to be insulting, but...
The reason it passed without comment is that it's just kinda cool, and the only one who doesn't immediately realize what it is seems to be you. The man is clearly shown having trouble getting up from a chair. It attaches to approximately the leg area. It shows him walking around.
There is enough contextual evidence here. You have no excuse to not figure this out.