I often hear from patients with low back pain that they have been told they have an “unstable
spine” or are suffering from “spinal instability”. Historically, this has been a way to describe low
back pain and a potential cause. But, because the term “instability” is so ambiguous, it is helpful
for us to understand the evidence behind low back pain and its relationship with spinal stability.
To begin this blog post we need to address an older view of spinal instability, and a newer one.
Previously, “spinal instability” has been used to reference a lack of static stability. A static
instability is one that resembles a Jenga tower with tons of blocks missing. But now, thanks to
research, we are beginning to realize that spinal stability should instead refer to a dynamic
control concept. Think of this as a Jenga tower, but now wrapped in saran wrap. It is free to
wobble and move all over, but it maintains its integrity and stays standing.
So let’s think again about that Jenga tower that is missing many blocks and is on the precipice
of falling. Now picture your spine and low back pain. This is not a great image and even gives
me a little bit of anxiety just thinking about it. In reality, this analogy falls apart when you
compare it to the human spine. Through extensive research studies, we now know that he
spine is heavily over-engineered and is incredibly stable. Think about it. Could a Jenga tower lift
a bag of mulch, go skiing, or run on a trail? I don’t think so. This is mostly because the Jenga
tower doesn’t have the amount of muscles surrounding the human spine. These muscles are
what give you this excellent stability! In fact, studies have shown that the spine is sufficiently
stable with only 2% of max muscle activation. So let’s throw out the idea that a spine is
intrinsically fragile or easily injured. This is simply not the case.
What do we mean then, when we talk about “instability”? Well, thanks to research, we are
realizing that the spine is a more dynamic system and one that is constantly moving and being
influenced by the muscles and nerves around it. Your trunk muscles are the primary source of
stability and function in regards to your spine. These muscles are where part of the answer lies
in regards to low back pain.
Think about your spine muscles in two different groups:
Global movers are the big guys that are easily fatigued but create the most torque for difficult
tasks. Local stabilizers are the smaller, more fatigue-resistant guys that keep everything running
smoothly in a coordinated fashion. We have found that the relationship between these two
groups of muscles is dysfunctional in low back pain, and can result in either too much activation
(global movers) or barely any activation at all (local stabilizers).
So, this means that when someone is having low back pain, they can have dysfunctional
patterns of muscle activation which cause pain. This is certainly not the only cause of low back
pain, but I believe it is the most common.
But, there’s another important topic about spinal instability we need to discuss. Imagine with
me here for a second. What if I told you that your spine was unstable and you were very likely
to injure it if you were not careful. Do you think you would be afraid to move or do your normal
activities? I sure would be. It is perfectly understandable to feel this way. And I often meet
patients who tell me they have been told exactly this by another healthcare practitioner. But
here’s the problem: fear of movement can actually cause more back pain. How? Well, studies
have shown that when a person is fearful of pain or movement, they alter how muscles activate
and fire around the spine. Through a multitude of pathways, this can cause more pain than
before. In fact, this system of fear and avoidance can create a positive feedback loop that just
keeps repeating over and over again, and will keep amplifying the pain each time around. Now,
I don’t know about you, but that is a cycle I don’t want to be a part of.
If you’ve made it this far into the blog, you have made it through some scientific verbiage and
abstract thinking in regards to low back pain and spinal instability. Good work! This is a very
complex issue and one that we are still learning more about as new research is published.
What do we take away from this discussion of spinal instability? Well, first, we need to
acknowledge that this is a complex issue and that no two cases of low back pain are the same.
But, there are some general principles we can use to help recovery from back pain:
●The human spine is heavily over-engineered and is not intrinsically unstable
●The muscles surrounding the spine play a massive role in pain-free movement and
overall functional stability
●In an episode of back pain, try not to be afraid of moving or attempting some of your
●Don’t listen to healthcare practitioners that use a lot of negative imagery or verbiage
when referring to your low back pain. It could hurt you in the long run!
●Low back pain is complex and cookie-cutter treatments don’t work for everyone. Seek
the care of someone who will listen to your unique situation!
If you or someone you care about would like help with low back pain, please don’t hesitate to
email me or call us!