Just for other would be developers who are too young to know.

Don't use a bad seat for 15 years and don't sit funny and not for long periods. Also find ways to stretch your leg muscles from the calf up every couple of days (A good 30 mins). Almost every time I had a major back outage stemmed from my left leg muscles which pull on your lower back when tight.

A great invention would be a seat/table which started at 0 degrees and over the course of the day moves to 45 degree recline so that weight is constantly redistributed to different parts of the skeleton.