I have one of these chairs from Therapod. It's about 4.5 years old, and theoretically sports a ten year warranty. Who knows where the purchasing paperwork is, even though it was horribly expensive. These are not cheap chairs.
Despite the long warranty period, the arm-rests have perished, the left armrest support snapped off completely about two years ago. Something went spung in the base a few minutes ago, leaving me teetering awkwardly. A bolt or something has sheared, taking the tension control off forward/backwards motion and the distance the seat-back tilts. I'm not sure I dare lean back in this in case something else lets go and throws me backwards on the floor.
Out on the back porch, I have some kitchen chairs that cost about 15 dollars each, and have been hanging around sturdily for more then ten years, with no signs of weakness.
As of ten or fifteen minutes ago, it is nearly a matter of acrobatics to sit in my Therapod chair without pitching forward or back.
Oh, yes. This is just what I need right now.