What do we commonly hear about lower back pain?
Slipped discs/ Disc Degeneration causes pain
Being out of alignment/ bad posture causes back pain
Bending is bad for your back
Improving core strength alleviates back pain
Is there any truth to these statements?
We are going to go through some of the evidence here. Please note that everybody is different and there are often multiple factors that have a role in any persons' pain experience. Nothing is ever black and white, there is always a lot grey!
Slipped and Degenerative Discs cause pain
This chart is looking at 3110 pain free patients who have had MRIs of their lower backs. It shows the percentage of people in each age range who have each finding.
Brinjikji et al. (2015) American Journal of Neuroradiology. 36(4)
I've focused on two common complaints: disc bulges and disc degeneration.
So the prevalence of disc bulges in pain-free people were 40% in 30 year olds, 50% in 40 year olds and and 60% in 50 year olds.
Disc degeneration is something else people are often told to worry about as it can cause pain and pushing on nerves. 68% in 40 year olds and 80% in 50 year olds.
A lot of these 'problems' often cause no problems at all.
I have seen this in practice when I was first training I met a lady in her late 50s from Sri Lanka. She had lower back pain. She had scans that had found she had severe compression of her cauda equina. This is a big problem and would require emergency surgery to stop her from losing the function of her legs and becoming incontinent. She had no symptoms or signs of this problem. I saw her over a period of months always asking if she had had any of the problems we would expect. None. The discs can protrude and cause havoc, but the worst ones are more likely to resolve. The disc is broken down and removed by our body. And from the statistics above, many don't cause any problems at all!
Bad posture causes back pain
These graphs are comparing people without back pain (black) and people with back pain (red) and the position of their lower backs and tail bones. Notice any difference?
Schmidt (2018) Journal of Biomechanics, Vol 70.
Me neither!
The researchers found no (significant) difference between the two groups. I.e. lower back posture is variable and does not correlate with either having pain or not.
This type of research tells us that posture does not necessarily relate to our levels of pain. Sure we can feel out of kilter, not feeling right, feeling wonky… but that it is more likely as a consequence of the pain, not the cause of it.
It’s like when people sprain an ankle. They limp and walk funny after the problem because of the sprain and the resulting pain. The limb didn’t cause the pain.
It can be reassuring to know there is no 'good' nor 'bad' posture. Posture is dynamic, individual and dependant on your situation.
Often I will see people with a posture which is swaying off to one side. More often than not, the opposite side to where the pain is. This is what’s called an antalgic posture (an ‘away from pain’ posture). It is likely that this posture came after the back pain and will improve as the pain improves.
Bending is bad for your back
A lot of the research that suggested that bending your back is bad was conducted on cadavers or animals. We are generally not dead nor animals... Much of the research was demonstrated on ‘neutral’ spines. Suggesting that injuries can happen in a neutral spine just as much as a bent one.
It is relative.
When picking a pencil off the floor it is safe to bend your back and you are unlikely to cause yourself any serious harm. However, you may want to keep a neutral back when deadlifting or picking up something heavier that you are used to (even this is debated!)
It is very difficult NOT to bend your back when picking stuff up. Even when focusing on the hips or knees, Your back will bend and that's OK! As below, shown by the red bars, when subjects had to squat and pick up a weight, their spines flexed (or bent)!
Dreischarf et al. (2016) Journal of Biomechanics. 49(6):890–5.
There is a lot of information in the graph above, so let me break it down:
Participants were asked to pick up a weight by either squatting (in red) or stooping (in blue). They had devices inserted into their spines (ouch!) which measured the load going through their backs. The top graph is how much forward bending is going on.
The middle graph is how much knee bending is happening
The bottom graph shows the load-ratio of squat to stoop through the participants spines. i.e. 100% means there is no difference and they are the same.
On average (median) there was only 4% less load going through the spines when squatting over stooping.
If we are worried about the load going through our spines when we bend (rather than keeping it straighter), there really isn't much difference in it!
The idea of bending is bad comes from the conventional “wisdom” that the back is fragile which is just. not . true.
Improving core strength alleviates back pain
Conventional “wisdom” is -
A weak core will cause back pain
Strengthening your core will alleviate back pain
According to a meta-analysis (a statistical study looking at the combination of information from many studies) by Smith et al (2014) there is no difference in benefit for pain and disability between ‘core’ focused exercises and any other exercises.
According to other research, we only need 5-10% of a maximum core strength to do normal activities.
This is not to say I am against ‘core’ exercises. Every patient is different and may find benefit in focusing their attention on their cores. But only focusing on the 'core' may be missing a trick. Having a strong core is good for many a thing, but it is not the magic bullet for lower back pain that we once thought. A lot of these beliefs have come from assumptions made from original old research. But we understand now that general exercises (anything that isn’t just specifically core work) is the same, if not better, for alleviating lower back pain. All we need to do is find the exercise that suits you!
I hope you have found the above interesting. There will always be new and, perhaps, conflicting research but it is important to keep an open-mind and always have you, our patients, at the forefront of our decision making.
Thanks for reading. Nathan, Your Friendly Neighbourhood Osteopath
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