You are exposed to whole-body vibration when you stand, sit or lie on a vibrating surface. This could be, for example, when you work on or in

• vesselsaircraft and helicopters
• trains
• forestry machines
• tractors
• buses and trucks
• forklift trucks
• construction machinery (wheel loaders, excavators, dump trucks).

Vibration can also be transmitted to humans via buildings, for example from work equipment in heavy industries, such as mills and stone crushers.

You are exposed to hand-arm vibrations when you hold or support a hand-held machine with your hand or arm. This could be, for example, when you work with

• grindersimpact nut runners
• hammer drills
• chisel and chipping hammers
• reciprocating saws
• chain saws lawn mowersaccessories, such as mounting sockets.

Transmission of vibrations

Hand-arm vibrations are also transmitted through controls and steering wheels in work vehicles, which means that you are then exposed to both whole-body vibrations and hand-armvibrations.

Leisure activities

You can also be exposed to different types of vibrations in your free time. Keep in mind that this may contribute to an increased risk of injury.

Pregnant employees should not be exposed to impacts or strong and sudden movements in the surface.

Pregnancy and breastfeeding

The following employees may be particularly sensitive to hand-arm vibration:

• people who already have permanent vibration injuries
• people who have a congenital predisposition to Raynaud's syndrome, so-called white fingers
• people who already have known vascular or nerve diseases.

If you drive vehicles or mobile machinery on uneven surfaces, combined with long periods of driving in the same body position, you may be exposed to higher exposure to whole-body vibration. This also increases the risk of you getting injured.

If you use hand-held machines incorrectly, you may be exposed to higher levels of hand and arm vibration. This also increases the risk of you getting injured. The same applies if you use accessories incorrectly.

Accessories are interchangeable equipment that the operator can replace or assemble with the work equipment after it has been put into service, such as a grinding disc, sanding paper or a specific machine part such as a vibration damper or bearing.

Remember that you should never hold a chisel, drill or nut socket while working. The reason is that the vibration is much higher there and go straight into the hands, without any damping at all. This significantly increases the risk of injury.

Read the instructions carefully

Always read the work equipment's operating instructions. There is information on intended use, recommended service intervals and accessories, among other things. The manufacturer or supplier must also state how much the work equipment vibrates (declared vibration values).

The load on the body is not only affected by the vibrations from the surface. Ergonomics also play a role. For example, the risk of being injured increases.

• if you operate the machine or vehicle for too long without rest and in the same static working position
• if, in addition to driving, you also lift heavy objects by hand
• if the driver's cab is poorly planned (location of controls and levers, or displays) you may be exposed to stretching and twisting
• if visibility is poor, you may be exposed to stress, muscle tension and fatigue which can lead to accidents involving other parties.

Here we describe some of the factors that can increase the risk of hand and arm vibration leading to injuries.

Poor ergonomics

A hand-held machine may have poor ergonomics, for example if it has a handle that requires you to grip harder to avoid dropping the machine or if the circumference of the handle is too large or too small. When you use such a machine, you will be exposed to higher levels of vibration, and you may also be at risk of a musculoskeletal disorder.

Another example is when you often work in poor postures, such as with bent wrists, which can lead to carpal tunnel syndrome.

Smoking and using snuff

In general, nicotine intake from smoking and snuff impairs blood circulation, which in turn increases the risk of injury if you work with hand-held machinery.

Cold and damp

If your hands are cold, blood flow decreases, which in turn increases the risk of injury. It is therefore important that you have dry, warm hands and keep your whole body warm when working with hand-held machines.

Transient problems may include

• impaired performance
• motion sickness
• impaired motor function
• visual disturbance
• increased risk of fatigue.

Permanent injury may include

• neck injury
• back injury

The permanent damage mainly causes discomfort in the lower back, shoulders and neck, with pain that can radiate into the legs and arms. Repeated impacts affect the discs in the spine, joints, and tendon and muscle attachments.

Research has not established whether whole-body vibration alone can cause discomfort. However, other simultaneous factors, such as poor musculoskeletal ergonomics, can increase the risk of discomfort and injury.

Examples of occupational groups where exposure to whole-body vibration is combined with other factors include drivers of tractors, buses, construction machinery and trucks.

Transient problems may include

• sensation of cold
• impaired sensation
• muscle fatigue
• numbness.

Permanent injury may include

• vascular damage (known as white fingers or Raynaud's disease)
• nerve damage, such as carpal tunnel syndrome
• muscle injuries
• joint injuries
• skeletal injuries.

White fingers (vascular damage)

Vibration can lead to white fingers, which is vascular damage in the hand. White fingers are characterised by temporary discolouration of the fingers and impaired sensation and function in the fingers. The paleness occurs due to restricted blood supply, and the affected areas will increase if exposure to vibration does not cease.

A person who already suffers from white fingers does not need to be exposed to vibration for the symptoms to appear. Symptoms may appear in cold weather, damp conditions, stress, smoking, other illnesses and medication.

Nerve damage

Damage to nerves and sensory perception in the hands can occur without the affected person noticing it or associating it with an injury. Symptoms of nerve damage can include numbness, tingling, reduced sensation, loss of grip strength and impaired mobility. There is no effective medical treatment for these nerve injuries.

Carpal tunnel syndrome

Carpal tunnel syndrome is a type of nerve damage that occurs when the nerves in the carpal tunnel are compressed. The syndrome can be caused by both vibration exposure and unfavourable work postures, such as working with bent wrists.

There is an effective medical treatment for carpal tunnel syndrome, but this is not the case for other nerve damage caused by exposure to vibration.

Accidents in the workplace

Vibration can also indirectly cause accidents. Impaired motor function or loss of sensation in the hands can cause clumsiness, which in turn can lead to an accident.

The most common cause of accidents at work is the employee losing control of hand-held machinery.