Emma suffered with two years of low back pain. Every standard test said the same thing: a simple strain. But a simple strain heals in about six weeks. Hers had been troublesome for two years, and nothing anyone had tried had touched it. The answer wasn’t in her back at all. It was a belly piercing.
To understand why a belly piercing can wreck a lower back, you need to understand a reflex that has been in almost every neurology textbook since Charles Sherrington described it in 1906; and that has been almost entirely ignored by clinicians ever since.
The withdrawal reflex: Hardwired, Automatic, and Brain-Free
Stand on a nail and your foot lifts before you’ve had a single conscious thought about it. Touch a hotplate and your hand is already pulling away by the time you register the heat. That is the flexor withdrawal reflex, and it is one of the most fundamental protective circuits in the human body.
It is a spinal reflex. The signal travels from sensors in the skin into the spinal cord, passes through a small chain of spinal interneurons, and comes straight back out to the muscles — without ever reaching the brain. The brain finds out afterwards. That’s why the reflex is so fast, and it’s why it works in animals whose spinal cord has been completely disconnected from the brain. Sherrington laid all of this out in The Integrative Action of the Nervous System, and it has been standard teaching for well over a century.
It is hardwired into you from before birth. It has nothing to do with exercise, fitness, or training — you cannot strengthen it in a gym, and you cannot switch it off by trying harder. And critically, it doesn’t just move one muscle. When the reflex fires, the flexor muscles on the stimulated side contract, and — by a principle called reciprocal inhibition, which Sherrington also described — the opposing muscles are automatically inhibited. One cannot happen without the other. The reflex alters movement across a whole region, not a single spot.
The withdrawal reflex doesn’t ask your permission and doesn’t report to your brain. It fires, it contracts one set of muscles, and it switches off their opposite numbers — every time, automatically, for as long as the stimulus is there.
It Doesn’t Need Pain
Most people assume this reflex is only about pain. It isn’t. Have someone poke you unexpectedly in the stomach and you’ll flinch — your abdominal muscles contract and you fold in the middle — without any pain at all. That flinch is the same withdrawal circuit, triggered by nothing more than an unexpected touch.
That’s possible because the nerve sensors in your skin are extraordinarily sensitive. They can register the movement of a single hair. And the group of nerve fibres capable of driving the flexion reflex — known in the physiology literature as flexor reflex afferents — includes not just pain fibres but low-threshold touch and pressure fibres too. Pain does trigger the reflex, but it is not necessary.
So when you’re poked and your stomach muscles contract, your back muscles are inhibited in the same instant. As soon as the poking stops, everything relaxes back to normal resting tone. The whole thing is over in under a second.
But what if the poking never stopped?
What the Literature Has Never Asked
Here’s the strange part. The withdrawal reflex itself is among the most studied reflexes in medicine — pain researchers use a version of it, the nociceptive flexion reflex, as a standard objective measure of pain sensitivity, and there are hundreds of papers on it. But almost all of that research looks at a brief, sharp stimulus and a brief, sharp response. What happens when the stimulus is not brief and not sharp — when it is low-grade, permanent, and sitting in the skin for years? What happens to the muscles that get inhibited when the trigger never goes away?
That question has received almost no scientific investigation at all. And it matters enormously, because persistent muscle inhibition isn’t a disease in itself — but it quietly makes illness and injury far more likely. Muscle weakness is a well-established risk factor for osteoarthritis, and in animal studies, experimentally induced muscle weakness has been shown to cause joint degeneration directly. A joint that isn’t supported by its muscles moves badly, gets strained, and gets inflamed. You can live with the inhibition for years without noticing, as long as you never demand full capacity from the muscles involved. You put your tiredness down to late nights, your headaches down to stress, and your sore back down to getting older. Your doctor may agree and prescribe something for it.
A Stud Is a Poke That Never Ends
Emma had a belly piercing. A stud through the skin of the abdomen is, to the nervous system, a permanent irritant. It was stimulating her abdominal muscles and inhibiting her back muscles, continuously, day and night, for two years. When I tested her, she was completely unable to generate resistance in the quadratus lumborum — the muscles at the side of the low back that help you bend sideways and twist — which explained precisely why her back would never stabilise enough to heal.
I asked her to change the stimulus by pressing the stud from right to left. The direction doesn’t matter; moving it does. Her quadratus lumborum returned to normal strength immediately. When the stud came out, her back muscles came back with it. She needed one small manipulation to restore movement in a single vertebra, and otherwise made a full recovery with no further treatment.
Louise’s case was the same reflex in a different location. Her back had “gone.” Bending forward, she could get no closer than ten centimetres from the floor, and straightening up meant walking her hands up her thighs because her back muscles wouldn’t hold her. I asked her to push her nose stud to one side. Immediately she bent forward, put her hand flat on the floor, and straightened without hesitation. Let go of the stud, and she was back to ten centimetres. Permanent removal relieved her pain at once.
Amy was fourteen: moody, tearful, exhausted, weak all over, failing at school. Removing her earrings allowed her muscles to fire again, and with a small dietary change she started to thrive.
Paul was a 21-stone man with disabling knee arthritis who had to walk down stairs backwards because his knees wouldn’t support him going forwards; his legs tested about as strong as a five-year-old’s. After his four large earrings came out, he walked down the stairs forwards. Within weeks his wife was watching him dig the garden and play with his grandchildren.
Location Matters
The withdrawal reflex is only triggered by activation of sensory receptors in the skin. It could be any of the sensory receptors designed to detect changes in pressure, stretch, touch, movement, temperature or chemistry. Sometimes a piercing has very little effect on muscle tone, other times it can be substantial. It just depends on how many receptors are irritated and how much they are stimulated.
Many women appear to have little to no effect from an earring through the centre of the earlobe where there is a low density of receptors, but a piercing too high or too low on the ear can produce dramatic changes, as the nervous system alters the tension in the neck muscles to pull away from the irritation. Sometimes only the neck is involved. Sometimes the inhibition spreads through the trunk or the whole body. Because you are completely unaware it’s happening, you assume everything is normal — and months or years later, when the headaches start, or the whiplash won’t clear, or an X-ray comes back showing arthritis, nobody thinks to connect it to the earrings you put in as a teenager.
I’ve seen the same effect from jewellery that doesn’t pierce the skin at all — heavy chains, rings, and watches in contact with the skin. Clive, thirty, with three months of severe low back pain, went from lying in agony on the table to walking around pain-free within minutes of my removing his heavy gold neck chain. Put it back on while he stood there, and his knees buckled. He later realised his pain had started a week after his wife gave him the chain for his birthday — and had vanished during the one week he’d been on holiday without it. I’ll be honest that I can’t fully explain why it's only metal in contact with skin that irritates when plastic, beads, leather or any other material usually doesn’t; that is clinical observation, not established physiology, and it deserves proper study.
Do Your Own Experiment
You don’t have to take my word for any of this. Take your jewellery off for two weeks and see whether your symptoms change. Put it back on and see whether they return. Repeat until you’re convinced one way or the other. If there’s no difference, wear the jewellery. If there is, you’ve just found something no blood test would ever have shown you.
And remember: you don’t have to lose what the jewellery means to you. A ring or a chain can carry love, loyalty, identity, belonging. Have it framed, keep it safe, put it under your pillow. The meaning stays exactly where it is. You just stop letting it switch off your muscles.
Simple solutions: remove as much metal from the body as you can — piercings, chains, watches, rings, toe rings. Teflon, plastic, and Bioplast piercings do not usually cause interference. Pierced earrings can be replaced with clip-ons; a watch can live in a pocket. And bear in mind that you may have more than one source of interference — removing jewellery won’t fix a symptom that’s actually coming from somewhere else.
To your strength!
References
- Derderian, C., & Shumway, K. (2023). Physiology, withdrawal response. In StatPearls. StatPearls Publishing.
- Andersen, O. K., Sonnenborg, F. A., & Arendt-Nielsen, L. (2001). Reflex receptive fields for human withdrawal reflexes elicited by non-painful and painful electrical stimulation of the foot sole. Clinical Neurophysiology, 112(4), 641-649.