I have experienced this personally in my office, as being a tall person I needed a chair that would be deep enough to give support to under-thigh as well as enough height to support my foot resting position. Everyday someone or the other will pull the chair to his/her desk, as not all chairs were of the same comfort level. So every morning I would look for the chair which I generally use for work and would even show a little fake anger to get it back.
Sitting on a comfortable chair did affect my work a lot as being in a comfortable and attentive position is very important for good output. If my body is not in a comfortable position, it would be pretty difficult to focus.
It is a general phenomenon, of I am hungry then my mind will focus only on food, and focussing on other things will be difficult. Similarly, if I am needed to sit and work for hours then the very first thing should be comfortable seating to enable me to focus on my mind to productive work, or else I will be standing again and again, moving here and there the whole time.
Live before you leave.
Another study was also made where a piece of light music was being played throughout the shift and the quality of the work improved a lot. So I strongly believe a good seat will make us perform better.
"Life is easier when you enjoy what you do"
Knowledge is power.