Why is sitting the leading cause of lower back pain?
A recent study has looked at the loading pressure of the individual discs of the spine in various positions. The internal pressure was measured in the unit pounds per square inch (PSI).
Lying down on either your side or stomach placed approximately 14 PSI of internal pressure onto each spinal disc.
Standing in a relaxed position increased the internal pressure per disc 5 times to 72.5 PSI.
Sitting upright, with a straight back produced a similar disc loading as standing.
Sitting in a slumped position like our average person on a couch at night nearly doubled the internal disc pressure to 120 PSI per disc.
Now you can easily see why sitting slumped on a couch or driving a car over a long distance can injure an already fragile back. It is much better to get off the couch and get walking or even running. Both these exercises load on average 87 PSI per disc; proof that they are much better for you than just sitting around!
Just for completion – what is even worse than sitting for longer than 30 minutes in a slumped position is adding vibration. Hence lower back pain is very common in truck drivers, forklift operators, sales representatives etc.