Enhancing H&S innovation

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When Jason Johnstone was medically discharged from his job as an operator/trainer after being diagnosed with hand-arm vibration syndrome (HAVS), he explored ways to prevent it happening to others.

JASON IS ONE of the few people in Aotearoa New Zealand diagnosed with HAVS, a condition that can be permanently disabling, where nerves and blood vessels are damaged by exposure to repeated vibrations from hand and power tools. Symptoms of HAVS include tingling fingers, numbness, pain, weakness, loss of dexterity and impeded blood flow.

Grey area around vibration exposure at work

If caught early enough, HAVS can be reversible – but in Jason’s case, his symptoms persist, flaring up at the slightest change of temperature or during certain activities.

‘All the crockery in our house has chips on it because, when I do the dishes, my fingers often go numb, and I tend to drop the dishes. It’s much worse in winter, and I’m pretty much stuffed when it comes to doing up buttons.’

But this hasn’t stopped Jason developing a new hand-arm vibration monitoring device and launching a business to address what he calls a massive grey area in New Zealand around vibration exposure in the workplace.

Power tools part of Jason’s work life

Jason has worked with power tools for most of his life. His HAVS symptoms became more pronounced while he was working at the Tiwai Point aluminium smelter as an operator/trainer – a job that involved use of jack hammers among other tools. The smelter did have time limits on use of certain tools, but intensity was also a factor.

‘My wife is a UK-trained general surgical registrar and diagnosed me with HAVS. I had no idea what HAVS was at that time. I told the smelter doctor my hands feel funny and was sent to see occupational health specialist Professor David McBride who formally diagnosed me.

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Lack of data on vibration exposure

‘I was told l couldn’t use the tools any more and was medically discharged from my job at Tiwai. But I noticed no one had any idea how the injury had occurred. Sure, vibration emitted from tools and machinery had caused my injury, but there was no data to explain this to the medical or health and safety professional. No one knew how much vibration I had been exposed to daily, nothing. It was all guesswork and seemed completely crazy – felt like I had wasted 20 years of my life.’

HAVS underdiagnosis in New Zealand

Jason’s experience led him to research current figures on HAVS here, revealing what he sees as an issue of underdiagnosis and misdiagnosis.

‘According to ACC data on HAVS, there were only 40–50 cases of HAVS in New Zealand from 2000–2018,’ says Jason. ‘This is unusual because 6,230 cases were reported in the UK in half of that time. Even if we consider that the two workforces are similar, based on population statistics, the incidence in New Zealand should have been 785 cases in 18 years or 44 cases per year.’

He also found that, during 1 July 2009 to 30 June 2019, ACC data showed there were 5,342 cases of carpal tunnel syndrome compared to the UK’s 2,930. Further, international research has shown vibration from hand tools does contribute to carpal tunnel injuries.

‘In the UK, doctors are trained to recognise HAVS. In New Zealand, they’re not, so it’s often misdiagnosed as carpal tunnel and that has been my experience after being told I have carpal tunnel. I believe it’s a problem in New Zealand given workers’ exposure in our construction, forestry, manufacture, transport and agriculture sectors.’

Innovative tool to help keep people safe

Jason identified the need for a user-based device to monitor vibration and capture much-needed data. He worked with software developer Digital Stock in Invercargill to develop a hand-arm vibration monitoring app and dashboard and sought a real workplace in which to trial it.

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Delta keen to trial app

‘I was sitting at the traffic lights and saw a Delta Utility Services ute draw up beside me and noticed it had a load of tools in the back. So, I followed it all the way back to Delta’s head office, went in and asked to speak to the health and safety rep.’

Delta is a Dunedin-based infrastructure maintenance company that services electricity distribution and communications networks and maintains the local authority’s green spaces. It had identified hand-arm vibration as a workplace hazard for its employees who often use vibrating machinery such as mowers and weed eaters for long periods.

So when Matt Sadgrove, Delta Health and Safety Manager, came out to meet Jason, he was immediately on board to help him trial the device.

‘I could see this was a smart idea – an innovative New Zealand-made tool to gather information to help us to make smarter decisions to keep our people safe,’ says Matt.

Matt is also a member of the New Zealand Community of Safety Innovation (COSI), a group of around 60 safety professionals who work together to identify new ways to improve health and safety. The group is supported by WorkSafe New Zealand, the New Zealand Institute of Safety Management, the Business Leaders’ Health and Safety Forum and the Health & Safety Association New Zealand (HASANZ).

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Helping eliminate vibration hazard

‘Our people are our biggest asset,’ says Matt. ‘Vibration is a major work-place health risk in New Zealand, and Jason’s device is an opportunity to accurately identify, manage and prevent this risk across our workplaces.’

Over the next year, Delta’s health and safety team and crews trialled the device. The crew provided valuable feedback about the robustness of the device for use in the field. Delta also helped Jason refine the app he had developed to make the data easier to interpret once collected.

The trial resulted in Delta purchasing new robotic mowers for the business, eliminating the vibration hazard and removing the workers from other hazards such as wasps, working on slopes and sun exposure.

Looking to make commercial device

For Jason, the trial has resulted in working prototype vibration detection bands and the launch of his business, Vibration Action. He is now seeking capital for further development and commercialisation of the device.

‘My goal is to incorporate the software into a Fitbit-like device that workers can wear all day, monitoring hand-arm vibrations and sending and receiving real-time threshold alerts and capturing data. I have plans to develop other devices that measure whole-of-body vibration and workplace noise levels and incorporate them into one system.’

Associate Professor in Occupational and Environmental Medicine at Otago University David McBride says Jason’s device is just what New Zealand needs. ‘As a workplace hazard, exposure to vibration is ubiquitous in New Zealand across construction, agriculture, horticulture and forestry. New Zealand needs to invest in more research in this area.

‘With Jason’s device, we have for the first time a simple tool using available technology to scientifically assess risk in the workplace, helping raise awareness of the issue, support training and education and, importantly, ensure people take adequate breaks.’

Daniel Hummerdal, Head of Innovation at WorkSafe New Zealand, which supports the COSI, says Jason’s device and Delta’s trial are a great example of ingenuity and motivation in New Zealand.

‘This journey underscores the purpose of COSI to connect people and organisations that are developing and trialling their ideas in isolation and bring them together. We can all be inspired and learn from each other and not only spread good ideas quicker but help translate them into actions that create better outcomes.’



1. What causes hand-arm vibration syndrome (HAVS)?
a. Using power tools that are too heavy.
b. Exposure to repeated vibrations from hand and power tools.
c. Playing contact sports.

2. What are some of the symptoms of HAVS?
a. Tingling fingers and numbness.
b. Pain and weakness in the fingers.
c. Loss of dexterity and impeded blood flow.
d. All the above.

3. What industries in New Zealand have been identified as having high exposure to vibration as a workplace hazard?
a. Construction.
b. Agriculture.
c. Horticulture.
d. Forestry.
e. All the above.

Answers: 1. b, 2. d, 3. e.

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