Squeezing – The Specific Cause

(Colm Campbell – Founder of the Back Shop)

(The following may be somewhat repetitious, however it is extremely important that you understand what causes back pain.)

I would guess that only a very small percentage of people are aware of the cause of back pain. I continually preach, “If you don’t know what causes back pain; you don’t know how to prevent it. Knowing what causes back pain gives you the information to do so.”

The spine is a vertical flexible column and a superb piece of electrical and mechanical engineering. However it wasn’t designed for sitting (for extended periods) when it collapses from the vertical ‘S’ shape, into a forward ‘C’ shape. this creates huge pressure in the discs causing them to progressively swell backward and eventually touch a nearby nerve root.

A simple experiment to illustrate: Bend a wooden ruler or a ball point pen. This causes huge stress in the object, causing it to spring back when the stress is relieved. Similar stress is occurs in the spine when you sit in ‘C’ shape.


The Structure of the Spine.

Very simply the spine consists of 24 bones (vertebrae) stacked one on top of the other and decreasing in size from the bottom (lumbar) to top (cervical). They are held together by the Disc Complex, which consists of (1) tight vertical layers of a tough fibrous flexible material known as the Annular Ligament. (2) Wrapped inside is the nucleus pulposus (the so- called Disc) which makes contact with the bottom and top of adjoining vertebrae and has a similar consistency to porridge. Bending the spine into a forward ‘C’ position in bad posture creates great pressure in the disc eventually stretching the annular ligament causing it to bulge, touch a nearby nerve root, and pain ensues.

“Touching a nerve causes back pain… breaking contact eliminates it.” Colm Campbell, 2016.


I will now attempt to draw a simple picture of what happens when a spine slumps into a forward ‘C’ position in bad posture. This will allow you to visualize exactly what is happening when you sit and how to prevent / eliminate pain. The hope is that when you sit, the primitive experiment below and its simplicity will flash across your mind and be a reminder to sit correctly.
The following experiment gives a picture of exactly how this occurs.

Place a saucer on a flat surface. This represents the bottom vertebra. Place a partially inflated small balloon in the saucer as indicated. This represents the disc. Place another saucer upside down on top of the balloon. This represents the top vertebra. Place a vertical object (a thick book standing upright would do) close by; say 5mm. This represents a nearby nerve.

Press down on the top saucer. This causes a 360degree symmetrical bulge.

Rotate the saucer forward as indicated. Press down hard. This causes the balloon to be squeezed at the front resulting in it bulging backward and making contact with the book.

Squeezing causes pain…

because touching a nerve causes pain
Perfect posture prevents pain…
because breaking contact prevents pain

This is what happens when the spine bends forward in bad posture; the adjoining vertebrae come closer together at the front, squeezing the disc, resulting in it bulging backwards and eventually stretching the annular ligament, which makes contact with a nerve. (Between every two vertebrae two nerves exit the spinal canal. One supplies the left hand side of the body, the other the right. They pass very close to the annular ligament. When touched, pain ensues.)