What is Vibration white finger
Vibration white finger is the name for a painful and potentially disabling condition of the fingers, hands, and arms due to vibration; it is also known as the hand-arm vibration syndrome. It is a secondary form of Raynaud’s syndrome, an industrial injury. It begins with initial tingling sensation in the fingers with numbness. The fingers then become white and swollen when cold and then red and painful when warmed up again.
Cold or wet weather may aggravate the condition. Picking up objects such as pins or nails becomes difficult as the feeling in the fingers diminishes and there is loss of strength and grip in the hands. The pain, tingling, and numbness in the arms, wrists and hands may interfere with sleep.
Use of the term vibration white finger has generally been superseded in professional usage by broader concept of HAVS, although it is still used by the general public. The symptoms of vibration white finger are the vascular component of HAVS.
The term vibration-induced white finger (VWF), was introduced by the Industrial Injury Advisory Council in 1970. Injury can occur at frequencies between 5 and 2000 Hz but the greatest risk for fingers is between 50 and 300 Hz. The total risk exposure for hand and arm is calculated by the use of ISO 5349-1, which stipulates maximum damage between 8 and 16 Hz and a rapidly declining risk at higher frequencies. The ISO 5349-1 frequency risk assessment has been criticized as corresponding poorly to observational data; more recent research suggests that medium and high frequency vibrations also increase HAVS risk.
Causes vibration white finger
Vibration white finger may occur in those using handheld vibrating tools such as sanding tools, hammer drills, jackhammers and chain saws. It may also be caused by holding or working with machinery that vibrates. Vibration promotes vasoconstriction through arterial smooth muscle hypertrophy, and damage to the endothelial cell walls; there is an increase in the release of vasoconstricting chemicals such as serotonin and thromboxane. Nerve damage also occurs.
Effects of Vibration White Finger
Excessive exposure to hand arm vibrations can result in various patterns of diseases casually known as HAVS or VWF. This can affect nerves, joints, muscles, blood vessels or connective tissues of the hand and forearm.
- Tingling ‘whiteness’ or numbness in the fingers (blood vessels and nerves affected): This may not be noticeable at the end of a working day, and in mild cases may affect only the tips of the fingers. As the condition becomes more severe, the whole finger down to the knuckles may become white. Feeling may also be lost.
- Fingers change colour (blood vessels affected): With continued exposure the person may suffer periodic attacks in which the fingers change colour when exposed to the cold. Initially the fingers rapidly become pale and feeling is lost. This phase is followed by an intense red flush (sometimes preceded by a dusky bluish phase) signalling the return of blood circulation to the fingers and is usually accompanied by uncomfortable throbbing.
- Loss of manual dexterity (nerves and muscles affected): In more severe forms, attacks may occur frequently in cold weather, not only at work, but during leisure activities, such as gardening, car washing or even watching outdoor sports and may last up to an hour causing considerable pain and loss of manual dexterity and reduced grip strength.
Read Also: What is an occupational injury
In extreme cases, the sufferer may lose fingers. The effects are cumulative. When symptoms first appear, they may disappear after a short time. If exposure to vibration continues over months or years, the symptoms can worsen and become permanent.
Clinical features of vibration white finger
There are some specific features and symptoms of vibration white finger:
- Symptoms of nerve damage include pain, tingling, numbness, and reduced dexterity. Initially symptoms are intermittent, but they may become continuous if exposure to vibration continues.
- Vascular manifestations include the cold-induced vasoconstriction (vasospasm) causing the fingertip or finger to turn white due to lack of blood supply. One or more fingers may be affected.
- The fingers may turn blue in more advanced cases when all the available oxygen in the blood is used up.
- When rewarming, the fingers turn bright red.
- Attacks can occur after using vibrating tools, especially if the hands are exposed to cold.
- Musculoskeletal complications include reduced grip strength, osteoporosis of the wrist or elbow, and bone cysts.
Who is at risk
This typically happens to people who regularly use certain types of vibrating tools, such as:
- Disc cutters
- Hammer drills
- Hedge trimmers
- Power mowers
- Concrete breakers/road breakers
- Cut-off saws (for stone etc)
- Impact wrenches
- Needle scalers
- Pedestal grinders
- Power hammers and chisels
- Powered lawn mowers
- Powered sanders
- Strimmers/brush cutters.
- Hand-held grinders
- Needle guns
- Concrete breakers
- Concrete pokers;
Generally, any vibrating tool that causes tingling or numbness in your fingers could lead to vibration white finger.
What are the early signs and symptoms to look out for
- Tingling and numbness in the fingers (which can cause sleep disturbance).
- Not being able to feel things with your fingers.
- Loss of strength in your hands (you may be less able to pick up or hold heavy objects).
- In the cold and wet, the tips of your fingers going white then red and being painful on recovery (vibration white finger).
If you continue to use high-vibration tools these symptoms will probably get worse, for example:
- The numbness in your hands could become permanent and you won’t be able to feel things at all;
- You will have difficulty picking up small objects such as screws or nails;
- The vibration white finger could happen more frequently and affect more of your fingers
Your description of symptoms and the fact that you have worked for a long time with vibrating tools may be enough to clinch the diagnosis of HAVS. However, tests are sometimes needed, especially if you are involved in a compensation claim. The tests may include checking your grip strength, your ability to perform fine hand movements and the response of your fingers to cold.
The Health and Safety Executive has a calculator that can help to gauge how much exposure you might have had to equipment that can cause hand-arm vibration syndrome
However, standard tests used to diagnose vibration white finger include:
- Vibrotactile threshold test: to measure the sensitivity of the mechanoreceptors in the nerves of each hand to stretch, texture and vibration.
- Thermal aesthesiometry test: to measure the thermal receptors (for cold/heat).
- Purdue pegboard test: to measure dexterity and any loss of movement in either hand.
- Cold provocation test: provides visual evidence of blanching.
The Control of Vibration at Work Regulations 2005, created under the Health and Safety at Work etc. Act 1974. is the legislation in the UK that governs exposure to vibration and assists with preventing HAVS occurring.
Good practice in industrial health and safety management requires that worker vibration exposure is assessed in terms of acceleration, amplitude, and duration. Using a tool that vibrates slightly for a long time can be as damaging as using a heavily vibrating tool for a short time. The duration of use of the tool is measured as trigger time, the period when the worker actually has their finger on the trigger to make the tool run, and is typically quoted in hours per day. Vibration amplitude is quoted in metres per second squared, and is measured by an accelerometer on the tool or given by the manufacturer. Amplitudes can vary significantly with tool design, condition and style of use, even for the same type of tool.
In the United States, the National Institute for Occupational Safety and Health has publish a database where values for sound power and vibrations for commonly found tools from large commercial vendors in the United States were surveyed.
The effect of legislation in various countries on worker vibration limits has been to oblige equipment providers to develop better-designed, better-maintained tools, and for employers to train workers appropriately. It also drives tool designers to innovate to reduce vibration.
Some preventive approaches includes:
Use of anti-vibration gloves: Anti vibration gloves are traditionally made with a thick and soft palm material to insulate from the vibrations. The protection is highly dependent on frequency range; most gloves provide no protection in palm and wrist below ~50 Hz and in fingers below ~400 Hz. Factors such as high grip force, cold hands or vibration forces in shear direction can have a reducing effect and or increase damage to the hands and arms. Gloves do help to keep hands warm but to get the desired effect, the frequency output from the tool must match the properties of the vibration glove that is selected. Anti-vibration gloves in many cases amplify the vibrations at frequencies lower than those mentioned in the text above.
Reactive monitoring: A simpler system, known as re-active monitoring, may be used by, for example, monitoring rates of usage of consumable items. Such a system was introduced by Carl West at a fabrication workshop in Rotherham, England. In this system, the vibration levels of the angle grinding tools in use was measured, as was the average life of a grinding disk. Thus by recording numbers of grinding disks used, vibration exposure may be calculated.
How do I protect myself?
As an employee, here are things you can do to protect yourself against the vibration white finger:
- Ask to use suitable low-vibration tools.
- Always use the right tool for each job (to do the job more quickly and expose you to less hand-arm vibration).
- Check tools before using them to make sure they have been properly maintained and repaired to avoid increased vibration caused by faults or general wear.
- Make sure cutting tools are kept sharp so that they remain efficient.
- Reduce the amount of time you use a tool in one go, by doing other jobs in between.
- Avoid gripping or forcing a tool or workpiece more than you have to.
- Store tools so that they do not have very cold handles when next used.
- Encourage good blood circulation by:
- Keeping warm and dry (when necessary, wear gloves, a hat, waterproofs and use heating pads if available);
- Giving up or cutting down on smoking because smoking reduces blood flow; and
- Massaging and exercising your fingers during work breaks.
What else can I do?
- Learn to recognise the early signs and symptoms of HAVS.
- Report any symptoms promptly to your employer or the person who does your health checks.
- Use any control measures your employer has put in place to reduce the risk of HAVS.
- Ask your trade union safety representative or employee representative for advice.
What can be done to improve the vibration white finger
- Keep hands as warm as possible, to stop spasms in the arteries of the fingers and to improve circulation.
- Smokers should cut down or quit, as tobacco causes the blood vessels to constrict, decreasing the blood flow to the fingertips.
- Take regular exercise to improve circulation.
- Avoid tight clothing that may restrict the blood flow.
- Try to avoid sitting for long periods of time – regular exercise, such as walking around a room, moving arms and legs to maintain circulation, will help make sure that fingers and toes do not get cold.
- Try to keep warm. If clothing gets wet, change it immediately. Drink hot drinks.
- Avoid touching cold objects.
Work place advice:
- Limit the use of vibrating tools. If practical, avoid them completely.
- See if its possible to replace the vibrating tool with an alternative method of getting the job done efficiently.
- Hold vibrating tools as loosely as possible and in varying positions.
- Ensure tools are well maintained; make sure cutting blades are kept sharp to maintain efficiency, and replace worn parts.
- Use tools correctly, and use the right tool for the job (to do the job more quickly and reduce exposure time).
- Store tools so that they do not have very cold handles when next used.
- Use anti-vibration gloves.
- Take regular breaks of at least 10 minutes every hour away from the tool.
- Choose low vibration brands/models of equipment.
Treatment of vibration white finger
If a worker has developed vibration white finger, management may include:
- Reducing or ceasing exposure to vibrating tools. However, in more advanced cases symptoms may be persistent after cessation of exposure.
- Encouragement to give up smoking
- Referral to a dermatologist, rheumatologist or neurologist for assessment and treatment, including calcium channel antagonists, and pain management.