Sitting is something that we do every day, either as part of our job, commuting or after a long day of work when relaxing on the sofa. The way we sit can however lead to long-term spinal health problems.
Let’s first take a look at the science behind sitting and then discuss how to do it properly. Nachemson and Elfstrom (1970) studied what happens to the intervertebral discs (IVDs) during different seating positions. The pressure that occurs within your IVDs when you sit (especially between the 3rd and 4th lumbar vertebrae) is at its least when the spine and hips are at 100 and 110 degrees. Sitting with your hips at 80 or 90 degrees results in IVD pressure increasing upwards of nearly 200%. The diagram below demonstrates IVD pressure when sitting in various positions according to the study done by Nachemson and Elfstrom.