How arm-hair stroker may help ease arthritis pain
AN arm-hair stroker may be an effective way to tackle pain caused by arthritis. The device, the size of a mobile phone, gently stimulates nerve fibres around hairs that respond to light, pleasant touch – such as stroking and massaging.
Known as C fibres, they are found in the skin wherever hair grows, as they share connections with hair follicles – the tube-like structures around the hair root.
A clinical trial is under way in Italy to see if using the gadget just twice a week can trigger sensations that override pain signals travelling from diseased joints to the brain, reducing pain in the process.
It is estimated that up to 50 per cent of adults in the UK suffer from chronic pain. A major cause is osteoarthritis, where wear and tear erodes cartilage – the tough, gel-like material that acts as a shock absorber for joints – to the point where bones rub together, causing pain and immobility.
While treatment such as physiotherapy and painkillers can ease discomfort, about 100,000 people a year in the UK undergo knee-replacement surgery due to the condition.
The arm-hair stroker is designed for those with moderate to severe arthritis pain anywhere in the body. Sensations in the skin are provided by a number of different nerve fibre types. While larger nerves – the motorways of the nervous system – carry more urgent messages, at speeds of up to 275mph, the small C fibres are more like footpaths, where messages travel at 2.2 mph.
And unlike larger nerves, these C fibres lack the protective covering made of myelin (a fat-rich, protective material), making them easier to stimulate externally.
The trial, being run at the Catholic University of the Sacred Heart in Milan, involves 60 volunteers who have moderate to severe chronic pain resulting from osteoarthritis of any joint.
Half will use the stroker – which has a rotating arm that connects with the skin as it spins round – for 30 minutes twice a week for three months. The rest will use a dummy device which looks similar but has no rotating arm. The device is held against the skin between the elbow and the wrist.
The trial follows research by the same team which found that using the hand-held gadget reduced pain by 23 per cent in a group of patients who had suffered from back pain or chronic widespread body pain for at least a decade. This result was achieved with just 11 minutes of use.
Researchers said that while it is
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not clear how it works, one theory is that pleasant touch blocks some or all of the pain signals getting to the brain by activating the opioid system, which is involved in controlling the transmission of pain signals. Stroking may also increase the production of the moodimproving hormone oxytocin.
Commenting on the research, Professor Sam Eldabe, a consultant anaesthetist and chronic pain specialist at James Cook University Hospital, Middlesbrough, said: ‘The [device] looks like a simple and elegant therapy for an often complex problem. It remains to be seen if the effect is constant.
‘We also need to see whether the device delivers the same outcomes outside a clinical trial setting, where the weight of patient expectations may boost outcomes.’