This is what is known in the trade as a one piece shell chair, I prefer to call them one piece hell chairs! With this type of chair the seat and back are either constructed as or remain fixed in a single piece.

Consequently, it isn’t possible to adjust the back and seat angle independently, all the user can do is alter the overall angle of the chair, but the back and seat remain fixed at a constant angle.

This is not a good idea for people who work in their office chair for long hours each day.

Twice recently in technical magazines I’ve seen articles on control rooms where likely $1 million or more has been spent on high tech equipment and in both cases the poor operators were sat in one piece hell chairs. Pity their backs after a 12 hour shift.

You’ll often find this type of seat in high end management chairs, frequently in leather and costing hundreds of dollars.

I suspect one of the reasons for their continued popularity is because they look big, important or luxurious, much like lounge chairs on wheels.

So, if you’re looking to replace your office chair, avoid these types of chair, your back will thank you.