Good question. I’m also having trouble picturing it exactly anymore (like I said, ~ 15 years ago), but what I recall is the brake levers seemed to be midway along the foam-ish covered handles, so one could grab behind or ahead of the brake levers, like when either initiating a standing or sitting motion, in both of which cases you’d definitely want it stationary, like you said.
But now that you mention this issue, it might be that it is a bad design overall for the infirm or unbalanced - who might have trouble coordinating exact hand placement, and better only for a fairly healthy person experiencing a temporary impediment.