Ergonomics design flaw

At work, today, they decided to round up the conference room chairs that ended up in cubicles because some conference rooms were empty. The also pointed out an ergonomic reason.

Basically, they say sit like the person in the picture, and you won't have back, neck, wrist, or other problems, and they're probably right, but they forgot something: how am I supposed to spend 5 minutes (let alone the 15 minutes between breaks) in the same, perfect position?

Don't tell us the easy parts of ergonomics, then quit, or maybe they're saying a desk job just isn't for me.

Disclosure: I do not have ADHD.