OT?

A lot of desk chairs and kitchen chairs have a center strut, that
compresses when one sits down.

What is the point of it?

Is it supposed to spring back, so everyone sits at the same height wrt
his arms and the desk or table?

Does it mean a height adjustment is no longer necessary on the chair?

Is it just supposed to accept the jolt when one sits down, so it's comfy
to sit down?
And does that mean a height adjustment is still needed?


I need as many as 3 new desk chairs, for the work bench, the office, and
the kitchen. I've only shopped a little.

One webpage says there should be adjustable lumbar support. I've had
some nice comfortable chairs but I never remember having that**. Not
really important right? **The best chairs wore out over 8 months ago,
so they're not here ot remind me.


Seems to me I need a height adjustment, a reclining resistance
adjustment, so it will recline but not before I'm ready, and I know
there is a third but I can't remember what it was.

Thanks.