Brian Mulligan: “Let us assume that you have a central low pain in your back when you arch backwards. Place the belt across your back at lower waist level. It lies across what is called the lordosis. That is the forward curve in the middle of our backs that is present when standing erect. It becomes humped when we bend over.
Holding each end of the belt firmly, take your forearms forward, then bend elbows and take hands up to make contact with the chest. The edge of the belt around your back should now be secured to the sping of the vertebra it lies over. “
“The purpose of pulling up on belt is to unload or free the facet joints at that level and enable you to arch back further with no pain. Try this and see if your pain with extension has gone and you can extend further.
Keep your hands in contact with chest all the time.
If there is pain or discomfort you may be at the wrong level. Try again with the belt about 2 centimetres higher or perhabs even higher still. Maybe you need it 2 cms lower.
If still sore, do not proceed.
As mentioned earlier, on the first day it is prudent to repeat the painless “SNAGS” only three or four times as a trial to ensure there is no latent discomfort from the exercise.”
Source: Self Treatments for back, neck and limbs by Brian Mulligan, 3th edition.
Watch the video clip: G.18. Lumbar Extension Self-SNAG