Whole Body Vibration at work: What you need to know

What is meant by Whole-body vibration?  

Whole body vibration (WBV) is the term for when vibrations are transmitted through the seat or feet of a worker. For example, this could be a person who drives a mobile machine, or other work vehicle, over rough and uneven surfaces as a central part of their job.  

Drivers of some mobile machines, including certain tractors, fork lift trucks and quarrying or earth-moving machinery, may be exposed to WBV and shocks,  

Whole-body vibration (WBV) mainly affects drivers of vehicles used off-road, such as: 

• dumpers 
• excavators 
• agricultural tractors 

However, it can also affect drivers of some vehicles such as 

• Those used on paved surfaces, such as lift trucks 
• Those on rails, such as gantry cranes 

This is associated with back pain. However, other factors in the workplace, such as poor posture and heavy lifting, are also known to contribute to back problems for drivers – it is a multifactorial condition. Further study is needed into the impact of WBV alone.  

Nevertheless, studies show WBV is associated with back pain, but also cardiovascular disease, various neuropathies, digestive problems, headaches, dizziness, motion sickness and possibly cancer.

Kevin Bampton, chief executive of the British Occupational Hygiene Society has pointed out that it is hard to show that WBV causes these directly in workplaces, where there are so many other health exposures in the same workers that could be attributable causes. This may be why WBV gains less attention than hand-arm vibration, although employers are tasked with managing both under the Control of Vibration at Work Regulations 2005. 

Workplaces have to keep in mind two areas of regulation around vibration: Hand Arm Vibration (HAV) and Whole Body Vibration (WBV). The regulations introduce action and limit values for hand, arm and whole body vibration. 

What are the legal requirements around Whole Body Vibration? 

There are two components, Exposure Action Value (EAV) and Exposure Limit Value (ELV).  

Legal duties of employers are to: 

• Assess vibration risks; 
• Eliminate risks at source, or reduce to lowest practicable level; and 
• Provide information and training to employees 

The daily EAV is 0.5 m/s² A(8). At this level employers should introduce technical and organisational measures to reduce exposure. 

The daily ELV is 1.15 m/s² A(8).  This is the maximum amount of vibration that an employee may be exposed to in a single day.  This may be a significant challenge for some industries.   

Existing health problems can also be aggravated by WBV and can result in raised concerns by employees. 

It is also important to consider any individuals who may be at particular risk – pregnant employees, young employees and those with existing back problems. 

Health effects of consistent exposure to WBV: 

• Digestive illnesses 
• Heart conditions 
• Impaired vision 
• Lower back pain 

The general principles of preventing whole-body vibration 

If employers comply with the Control of Vibration at Work Regulations 2005 and follow HSE’s guidance, it will help them manage the risk of back pain and other conditions resulting from Whole-Body Vibration. Some of the requirements may be relatively straightforward and easy to implement, e.g. filling in potholes on unmade roads. 

Employer responsibilities include: 

• avoiding risks; 
• evaluating the risks which cannot be avoided; 
• combating the risks at source; 
• adapting the work to the individual, especially with regards to the design of workplaces, the choice of work equipment and the choice of working methods; 
• adapting to technical progress; 
• replacing any dangerous vehicles with non-dangerous vehicles; 
• developing a prevention policy which covers technology, organisation of work, working conditions and the influence of factors relating to the working environment; 
• giving appropriate instructions to employees. 

Employers have to take action to prevent risk from exposure to vibration. They need to consider whether there are other ways or machines that would eliminate the exposure to the vibration, especially where large shocks and jolts are involved. If this isn’t possible the exposure should be reduced to as low a level as is reasonably practicable. This includes: 

• introducing control measures whenever your employees’ daily exposure to vibration is likely to exceed the exposure action value, and 
• not exposing your employees above the exposure limit value. 
• Risk is likely to be low for exposures at or just above the exposure action value while exposures closer to the exposure limit value will need more control. 
• Some controls may take time to put in place, particularly where machines must be replaced or new ways of doing things have to be developed. This would normally require an action plan. The plan should state clearly which managers, supervisors and employees are responsible for its delivery and by when. It should also include the need to test the controls.

Employer responsibilities: Maintenance and adjustment of seats 

Machine manufacturers/suppliers must ensure that the seat adjustment controls are readily accessible and easy to use. The same applies to the retrofitting of replacement seats. 

Operators should be trained to set seats correctly. Incorrect seat adjustment is frequently the source of poor posture and unnecessary vibration or shock. 

Operators should also check, lubricate and maintain seat, cab and chassis suspensions in accordance with the manufacturer’s instructions. 

Considering the choice of seat (including suspension seats) and the choice of tyres, and regular maintenance of vehicles (including their seats and suspension) and also maintenance of unmade roads and ground conditions throughout sites to suit the machines that use them will greatly reduce shocks and jolts.

Employer Responsibilities: Training 

A competent and skilled machine operator who drives in a smooth and controlled manner will often generate lower exposure to vibration than a less skilled operator or someone working under pressure. It is clear that training is necessary so that operators handle the machinery in a way that exposure is minimised. 

It is important to train machine operators but also to give them information about the risks of lower back pain in their jobs;  

Operators should be aware of the factors that are within their control like choice of speed and route taken.  

They should also know how to set their seat for good posture and to set the suspension correctly to minimise vibration, and how to locate and adjust convex mirrors and CCTV so that they can use them without twisting and stretching. Finally they must also be able to identify and report faults. 

Ignoring the risks of whole-body vibration exposure can lead to long-term health complications for vehicle operators, and increased costs for employers.

Control measures for Whole Body Vibration  

Control measures for whole body vibration include: 

• Introducing working methods which eliminate or reduce exposure to whole body vibration, e.g. replacing manned with unmanned machines such as remotely controlled conveyors; 

• Choosing work equipment of appropriate efficient design, i.e. the choice of vehicle can be an important means of reducing exposure to vibration, through the difference in vibration emissions of the vehicle itself (although this needs to be considered alongside choosing the most appropriate vehicle for the task) 

• Ensuring that visibility is such that the machine can be operated without stretching and twisting 

• Ensuring that it is easy to get in and out of the machine by using handholds and footholds so that the temptation to climb or jump is minimised 

• Ensuring that access to manually loaded areas is not impeded by the machinery structure and involve minimal lifting, and if the machine cab is the sole workplace of the machine operator, including break time, it should have sufficient space and facilities for rest periods. 

• designing the layout of workplace sites to reduce the need to transport materials 

• Limiting the duration and magnitude of exposure – when all reasonably practicable steps have been taken to reduce the vibration magnitude, if there is a lack of PPE the final resort for compliance with the exposure limit value is to limit the duration of exposure 

• Giving adequate rest periods – a recommended precautionary measure is to take a short break between operating mobile machinery and manual handling of materials, to give tired muscles time to recover before handling heavy loads 

• Protecting employees from cold and damp – cold exposure may accelerate the onset or worsen the severity of back pain. It is good practice to ensure that those working in the cold are provided with warm and waterproof clothing. 

• Reducing exposure below the exposure limit value – you must not permit an employee to be exposed above the exposure limit value.

But isn’t vibration good for injuries in certain scenarios? 

Whole-body vibration (WBV) is offered as a therapy for some sports injuries – but in larger doses it contributes to work-related musculoskeletal disorders (MSDs) that cost employers is sickness absence and reduced productivity. 

WBV vs HAV   

There is a perceived absence of enforcement action around WBV compared with hand-arm vibration – this could be due to the fact that HAV leads directly to a diagnosable condition: hand-arm vibration syndrome, whereas the issues caused by WBV can be caused by various factors.