Prolonged static sitting is a frequent aggravating factor for individuals with spinal pain. The single best advice that we can give as a PT is to tell them that they must frequently interrupt static sitting, ideally at least every hour.
However when people are driving, they are not going to get out of their car and go for a walk on the highway or do 10 press-ups. When people are working on their computer, they often even eat their lunch in front of the screen and don’t get up.
Uninterrupted postures may lead to the spine becoming sensitized. Since we typically spend a lot of time in flexed postures, the spine usually becomes sensitized into flexion. Therefore the logical treatment is interruption of the posture by moving into extension, as proposed by McKenzie.
The single best lumbar exercise for interrupting sitting (outside of getting up and walking) is to do what I refer to as “pelvic pumps”.
Sit in a full flexed posture, then roll on the ischial tuberocities and take your spine actively into extension, with the intention of extending the low lumbar spine. The pelvic pumps should ideally be done rhythmically 5-10 X for every hour of uninterrupted sitting.
However, if the symptoms develop let’s say after 30 minutes of sitting, then the pelvic pumps should be done every 15 minutes. They should ideally be done BEFORE the onset of symptoms.