"The Biomechanics of Back Pain,
What We Know So Far."
This is going to be an account
of the mechanical and biological
origins of low back pain.
I'm Mike Adams.
I'm professor of biomechanics at
the University of Bristol in the UK.
My background is in
physics and in biology.
I'm not a clinician, and
I don't treat patients.
But I will, of course, be
dealing with clinical matters.
Well this is a running order of
the topics in this presentation.
First of all, I'll begin
with some functional anatomy.
I'll describe some
features of anatomy
I'll be wanting to
refer to later on.
Then I'll tackle the
most important question,
where does back pain come from?
I'll then go on to discuss spinal
injuries under three headings.
I'll consider where the forces
come from that act on the spine,
and then describe how
those forces can injure
different structures in the spine.
And then, under vulnerable tissues,
I'll try to explain why some people hurt
their backs, where other people
seem to get away with
loading them very severely
without any adverse consequences.
The next, topic spinal degeneration,
will be the biggest single topic.
And here I'll try to explain
how injury to specific tissues,
particularly cartilage, can
lead to degenerative changes,
and how these degenerative changes
can lead to chronic back pain.
The final topic,
I'll deal with very briefly.
And then I'll pull the talk
together in the final slide.
The diagram on the left hand side
here shows you along the spine.
The bones, or vertebrae, are
separated by intervertebral discs,
shown in blue.
Each intervertebral disc
is a pad of fibrocartilage,
about one centimeter high.
And because the
discs are deformable,
it means that the whole spine can
move slightly, not a great deal.
On the right hand side
is a photograph of a
typical mature intervertebral disc.
The disc consists of two tissues.
In the center is the
which tends to be soft and
squidgy, high water content.
And it can behave like
The nucleus is surrounded by the
concentric layers, or lamelle,
of the annulus fibrosis.
This is mostly made of collagen. It
provides great mechanical strength
to an intervertebral disc.
Now before I leave this slide, if
you go back to the left hand side,
look at that dotted line.
That dotted line runs down
the long axis of the spine.
And forces acting down the long
axis of the spine, following
this dotted line, is what
I'll be referring to as
a compressive force on the spine.