There is a pattern that comes up a lot in the clinic. Someone has been well for weeks, with their pain under control, and suddenly it returns. They have done nothing different. They have not lifted anything heavy, they have not slept badly, they have not made a sudden movement. But something has changed: they are going through a period of a lot of stress at work, or there is something difficult at home, or that week has simply been more demanding than usual.
When I ask them, many already know. "It always happens to me when I'm stressed." They know it, but they don't know why. And without understanding the mechanism, it is hard to work on it.
It is not psychological in the way you think
When someone suggests that stress may be related to physical pain, the usual reaction is defensive. And that is understandable: it sounds as if you are being told the pain is in your head, that it is not real, that if you were calmer it would not happen.
That is not it.
The relationship between stress and musculoskeletal pain is physiological. It is not an interpretation, and it is not psychological in the everyday sense of the word. It is a concrete mechanism that takes place in the body and that is explained by the biology of the autonomic nervous system.
What stress does to your muscles
When the nervous system perceives a threat — real or anticipated, physical or emotional — it activates the sympathetic nervous system. What we know as the fight-or-flight response. In that state, the body prepares to act: the heart rate rises, breathing becomes shallower, the muscles activate pre-emptively so they can respond quickly.
That pre-emptive muscle activation is involuntary. You do not control it. And it does not distinguish between a real physical threat and the chronic stress of a demanding job, a difficult relationship or sustained uncertainty.
In a state of chronic alertness, the paravertebral muscles — the ones that surround the spine — hold a higher baseline contraction than usual. The trapezius, the scalenes, the deep lumbar muscles. All under constant tension, as if the body were always ready for something that never arrives.
Moseley and Butler document, in their work on the neuroscience of pain, how the central nervous system modulates the perception of pain according to context: the same stimulus hurts more when there is stress, perceived threat or a sense of lack of control (2015 · PMID 26051220). Not because the tissue has got worse. Because the nervous system has a lower alarm threshold.
What this means in practice
It means there are days when your back hurts more and it is not because you have done anything physically different. It is because the level of activation in the nervous system is higher, and that translates into more muscle tension and more sensitivity to pain.
It means rest is not always the answer. If the origin of the episode is a nervous system on alert, resting the body does not necessarily switch off the alarm.
It means that recurring pain with no clear structural explanation — the kind that comes and goes without an obvious physical reason — may find an important part of its answer here.
And it means, above all, that working only on the tissue without attending to the state of the nervous system leaves part of the problem untouched.
What this is not
This is not an invitation to meditate instead of doing physiotherapy. It is not saying that movement does not matter. It is not psychologising pain or reducing it to an emotional issue.
It is recognising that the musculoskeletal system and the autonomic nervous system are not sealed compartments. That a sustained level of stress directly affects muscle tension, intra-abdominal pressure, breathing and the pain threshold. And that an approach which does not take this into account is working with incomplete information.
What can be done
It is not about eliminating stress — that is not always possible or within your control. It is about giving the nervous system concrete tools to lower its level of activation when it is too high.
Slow costal breathing activates the vagus nerve and shifts the system towards the parasympathetic mode. Progressive, safe movement teaches the system that it can load without anything bad happening, reducing hypervigilance. Good-quality sleep regulates cortisol, which in turn affects baseline muscle tension.
None of this is secondary to the treatment of back pain. In many cases it is the central part.
What changes when you understand the mechanism
Something happens when someone understands that their back hurts more during stressful weeks not by chance but because of a concrete physiological mechanism. Their relationship with the pain changes. It stops being something that appears arbitrarily and incomprehensibly and becomes information about the state of the nervous system.
That information is useful. It lets you act earlier, with better judgement. It lets you avoid panicking when the pain returns — because you understand why it has returned and you know what you can do.
In the Reset Program, Session 1 introduces this axis from the start. Not as optional theory, but as part of the map you need to understand your back. Because once you know that stress has a real, measurable impact on your muscles, you already have a variable you can work on.
If you recognise this in your own back, the Reset Program works on all four axes of the method from session 1.