Ignoring the risks of whole-body vibration exposure can lead to misery for vehicle operators, and hefty sickness bills for their employers. As industry ramps up after extended shutdowns, the risks could be more present than ever.
Whole-body vibration (WBV) may be good for us in small doses – it is offered as a therapy for some sports injuries – but in larger ones it contributes to work-related musculoskeletal disorders (MSDs) that cost employers dear in sickness absence and reduced productivity.
Yet WBV gains less attention than hand-arm vibration, although employers are tasked with managing both under the Control of Vibration at Work Regulations 2005.
‘I haven’t seen any prosecutions for WBV,’ says Satish Lakhiani, a consultant with Essel Acoustics specialising in noise and vibration. ‘I’ve asked many people in the industry and nobody else has seen one.’
The reason for the lack of enforcement compared with hand-arm vibration is that the former leads directly to a diagnosable condition: hand-arm vibration syndrome. However, WBV – commonly transmitted through the seats or feet of vehicle drivers and to users of some heavy pneumatic tools – can contribute to or trigger lower back pain, a notoriously multifactorial condition.
‘Health studies show WBV is associated with back pain, but also cardiovascular disease, various neuropathies, digestive problems, headaches, dizziness, motion sickness and possibly cancer,’ observes Kevin Bampton, chief executive of the British Occupational Hygiene Society. ‘But it is hard to show that they cause these directly in workplaces, where there are so many other health exposures in the same workers that could be attributable causes.’
Exposure limits: Measure for measure
IOSH head of health and safety Ruth Wilkinson says the place to start measuring the risk of WBV is knowing how long workers are exposed each day.
‘It is important to note that this isn’t the length of their shift,’ says Ruth, ‘but the actual duration of being exposed to the vibration itself, so observation and timing of the task will be required and any breaks or non-WBV work should be excluded. Manufacturer or supplier information will also be useful in identifying the vibration magnitude.’
The GB Health and Safety Executive’s (HSE) approved code of practice on WBV (see Resources) states: ‘An assessment of exposure based on published information will normally be adequate, but you will need to be able to show, at least from 2010 (or 2014), that the measures you have put in place will prevent the exposure limit value being exceeded. If you cannot do this using published data, you may have to arrange for measurements to be taken.’
‘Based on your circumstances, procuring specialists to help with the measurement may be required,’ says Ruth. ‘Measurement of vibration requires additional skills, including training in the use of the specialised measuring equipment.’
The HSE provides a WBV calculator on its website (see Resources), which allows samples of individual exposure taken in a vehicle to be averaged and inputted to see if exposure is over the exposure action and limit values in the Control of Vibration at Work Regulations 2005.
‘IOSH promotes the prevention-first approach to back pain,’ says Ruth, ‘so that risks from WBV are prevented or controlled in addition to the identification and management of other risk factors associated with back pain and musculoskeletal symptoms. It is also important to consider any individuals who may be at particular risk – pregnant employees, young employees and those with existing back problems.’
All vehicles vibrate, but driving on normal roads does not usually expose people to excessive WBV. A study published in 2008 examined 1000 patients referred to Southampton General Hospital with lower back pain, including professional car and van drivers, reported that ‘associations with the six metrics of WBV were weak and not statistically significant, and no exposure-response relationships were found’.
Vehicles creating a hazard are those used away from paved surfaces: quad bikes and tractors, excavators and dump trucks. The jarring effect of bumpy fields, construction sites and unmade roads is best imagined by visualising the skeletal shocks transmitted when travelling in a speedboat – another vehicle type identified by the GB Health and Safety Executive as a potential WBV risk.
‘I have done WBV assessments in factories where the forklift trucks go out into the yard, which is full of bumps and divots,’ notes Satish. ‘A forklift with hard wheels and often a lock of suspension is
not meant for that environment.’
Innovations such as off-site prefabrication in construction and automating activities on industrialised farms should reduce the number of vehicle movements and cut driver exposure. ‘For the large organisation, WBV should be a diminishing issue,’ says Kevin. ‘But it will be a long time before technical developments such as remote control – removing the operator from the vehicle – permeate the SME world.’
He recommends a three-pronged approach to managing the risk. ‘If you were being systematic in your risk assessment, first you would check the environment, then check the vehicle and then check the people.’
The environment may be the hardest element to influence, but checking regular vehicle routes and remedying potholes will give a smoother ride.
Attention to vehicles begins with procurement. Safety professionals should be able to influence buying decisions for mobile plant or off-road vehicles to ensure that they are fitted with effective vibration damping, especially the seating – manufacturers should specify vibration levels. Factors that compound vibration’s effect on a body include poorly laid-out controls that require overstretching or unnatural posture, notes Satish.
Fast facts: WBV in numbers
- In 2015 in the US, 774,900 workers in transportation, warehousing and utilities missed days of work because of injury or illness. This is all causes, not just vibration.
- Common injuries and illnesses include back, neck and shoulder pain, headaches and dizziness, motion sickness and gastrointestinal, cardiovascular and peripheral sensory problems.
- Workers in the construction, mining, forestry, maintenance, automotive and agriculture industries are also at risk.
- Women working full-time hours and exposed to WBV above the European limit of 0.5m/s² were at increased risk of pregnancy complications including preeclampsia, gestational hypertension and gestational diabetes.
The whole person
Kevin’s third element of control, the people, is addressed through worker awareness and training. Driving speed is important: a rally-car pace will result in the driver feeling the bumps more. Knowing how to adjust the driving seat is important, as is taking adequate breaks – and rostering individuals to limit their exposure is an employer’s duty. ‘As well as going back and forth in a vibrating vehicle for long periods, operators can be jumping out of cabs and doing other heavy jobs, such as changing excavation buckets,’ says Kevin. ‘It all contributes to the impact on the body.’
Satish and Kevin note that it is no good schooling someone in good practice on work vehicles if there are other parts of their jobs, such as manual handling, where lack of training still leaves them at risk of an MSD.
The multifactorial aspect of back pain suggests that training could extend beyond the range of an operator’s work tasks, suggests Kevin. ‘If the employer places an emphasis on back health – because without a strong back you can’t do most of what you are doing – that will influence behaviour outside of work,’ he argues. Satish takes this holistic approach further, pointing out that general fitness is worth considering when assessing risk. ‘Somebody with a poor diet who is out of shape can be more likely to get injured than someone who is fit and healthy.’
Now is a good time to be thinking about WBV, says Kevin, as employees return from furlough. ‘Their back strength may have changed because of reduced work or other activities such as a lot of gardening that will have placed different strains on them.’ Asking whether operators have sustained any aches or sprains during their time away from the workplace is a good start, he suggests, along with brief refresher training and checking the state of roadways and equipment to see that they haven’t degraded badly during shutdowns.
Without these precautions, 18 months’ attrition to environment, vehicle and people, plus the pressure to make up for lost productivity, could lead to an uptick in back problems caused or worsened by WBV.
‘It’s that combination of small factors that might cause more difficulties,’ Kevin concludes. ‘But for something that can have a really negative effect on productivity as well as people’s health, these are pretty straightforward actions.