What is Hand Arm Vibration Syndrome (HAVS)?
Hand Arm Vibration Syndrome also known as HAVS is a condition caused by extensive use of hand-held power tools. It affects the vascular, musculoskeletal and neurological system causing permanent numbness and tingling in the hands and arms, as well as causing Vibration White finger.
HAVS can also damage the motor nerves that control the hand muscles. If it is caught early, preventative methods are available and recovery may occur. Other names for this condition include vibration white finger and Raynaud’s phenomenon.
Causes of Hand Arm Vibration Syndrome
HAVs is caused by frequent use of vibrating hand held tools including:
Power drills
Chainsaws
Sanders
Lawn mowers
Machines that constantly vibrate
When someone uses these tools the vibrations are absorbed by the hands and arms, which can cause injuries to the small nerves and capillaries in the fingers and hands. 1 in 10 people who work frequently with hand held vibrating tools may develop HAVS.
Symptoms of HAVS
Some people may experience symptoms after a few months of exposure to vibrating power tools. If left untreated the symptoms can worsen and become permanent. The progression of these symptoms can depend on the length of exposure to vibrating tools, as well as lifestyle factors such as smoking and pre-existing health conditions.
The most common Symptoms include:
Reynaud's Syndrome - Raynaud’s Syndrome causes the tips of fingers to go white when exposed to cold environments or touching cold objects, due to restricted blood flow. Vibrating tools are one of the main causes of Raynaud’s Syndrome, and is characterized by the fingers turning white, then blue and finally red when blood flow returns to the fingertips.
Nerve Damage - This symptom relates to Nerve damage in the fingers and hands. Nerve damage in the fingers can also feel like pins and needles or tingling in one or more fingers. This symptom can initially be intermittent but worsen over time making it difficult to complete tasks, like handling screws or fastening buttons. In some cases, numbness in the fingers can become permanent and the damage may extend to joints and bones, that can lead to chronic pain.
Muscle Damage and Reduced Strength - Damage to the muscles in the hands may result in reduced grip strength and dexterity. This can also cause aches and pains in the muscles in the hands and forearms. Hands may feel sore and stiff when trying to complete fine motor tasks.
How do HAVS Symptoms progress?
As HAVS Symptoms worsen they can become permanent if preventative measures are not put into place. Health professionals use the Stockholm Workshop Scale to determine the severity of each case of HAVS. This scale classifies the symptoms into five stages, monitors symptom progression and helps to guide treatment and management.
The Stages are broken down as follows:
Stage 0: No signs or symptoms of HAVS.
Stage 1: The worker experiences intermittent numbness without tingling in the tips of one or more fingers.
Stage 2: Persistent numbness in fingertips and the middle of the fingers near the knuckles with reduced sensory perception.
Stage 3: Frequent attacks that affect all the fingers with persistent numbness and a significant reduction in sensory perception.
Stage 4: The same symptoms as Stage 3 but with very severe numbness in all of the fingertips.
This five step system provides a starting point for health care professionals to assess the damage done by HAVS, and can act as a guide for treatment and prevention.
What Effects do these Symptoms have?
The effects of prolonged exposure to vibrating hand tools can result in three types of injuries:
1. Musculoskeletal Symptoms
Continuous use of vibrating tools can lead to muscle weakness and fatigue, reducing overall grip strength. Over time, the constant impact can cause inflammation and pain in the connective tissues in the hands and arms leading to Tendonitis and Arthritis. This can severely impair overall dexterity and hand function.
Carpal Tunnel Syndrome (CTS) is also a repetitive strain injury that is associated with HAVS. This happens through nerve compression in the tissues of the wrist. The tissues can become swollen from continuous use of vibrating hand tools further compressing the nerves in the wrist and causing CTS.
Management and Prevention:
Managing Musculoskeletal injuries caused by HAVS includes, reducing vibration exposure, taking regular breaks, using tools and PPE designed to reduce vibrations, and completing exercises to strengthen the muscles and improve circulation in the hands and arms.
2. Neurological Symptoms
Prolonged exposure to hand-arm vibration can have adverse effects on the nerves in both the hands and arms. One of the earliest and most common signs of neurological damage is the feeling of “pins and needles” or numbness in the finger tips. This symptom is caused by nerve damage in the fingertips that are responsible for touch and temperature sensations.
As Nerve damage in the fingers and hands progresses, the loss of fine motor control in the hands also worsens. The chronic numbness in the finger tips can also be experienced alongside chronic pain and discomfort in the joints of the fingers and hands. Persistent numbness can often indicate severe nerve damage, where nerves can no longer regenerate or recover from the repetitive trauma caused by vibration exposure.
Management and Prevention:
Managing neurological injuries from HAVS includes taking regular breaks from the vibrating tools, using ergonomic tools, and in some cases undergoing physical therapy and medical treatments to manage pain.
3. Circulatory / Vascular Symptoms
Vascular injuries affect the blood vessels in the hands and fingers, leading to various circulatory issues. When the small blood vessels in the fingers are subjected to constant vibration, damage is caused, leading to abnormal constriction in response to stress or cold.
This continuous constriction of the blood vessels, reduces blood flow in the hands and fingers, causing the fingers to turn white, then blue due to a lack of oxygen and the ability to regulate blood flow effectively. Persistent lack of blood flow, can cause ulcers and sores on the fingertips, as well as thickened nails and dry skin. These changes often indicate irreversible damage and long-standing vascular impairment.
Management and Prevention:
Preventing vascular injuries from HAVS involves using anti-vibration gloves, taking regular breaks to reduce the exposure to vibrations and maintaining a warm environment to reduce the risk of the fingertips turning cold. Early intervention is crucial to prevent further vascular damage.
HAVS Exposure Limits
To protect workers, exposure limits are set by the Control of Vibration at Work Regulations 2005. These limits include the Exposure Action Value (EAV) and the Exposure Limit Value (ELV).
Exposure Action Value (EAV):
The EAV is an exposure level that employers are required to set to control daily exposure limits. For Hand-Arm Vibration the daily limit is set to 2.5 m/s² per 8 hour day. If this limit is exceeded the employer must take action and provide measures to control exposure, such as providing PPE and modifying the working process.
Exposure Limit Value (ELV):
The ELV is the maximum amount of vibration exposure an employee may be exposed to in a single day. This value is set at 5 m/s² per 8 hour day. Exceeding this limit is prohibited and immediate steps must be taken to reduce exposure below this limit, which includes stopping work if necessary and implementing measures to prevent further exceedance.
Employers must adhere to the limits that are set to comply with the workplace safety regulations that are designed to prevent HAVS.
Industries with High Risk of HAVS
HAVS is an occupational hazard in many industries due to the prolonged exposure to vibrating machinery and tools.
Here are a list of industries with the highest risk of HAVS:
Construction: Workers often use hand held grinders, concrete breakers and jackhammers that produce high levels of vibration.
Engineering: Involving the use of grinders, polishers and other vibrating machinery.
Mining and Quarrying: Workers often use heavy machinery and drilling equipment that contributes to high vibration exposure.
It is crucial to have preventative measures in place to reduce the risk of exposure and developing HAVS. These measures include using anti-vibration gloves, taking regular breaks, ensuring that all tools are well maintained and reducing the amount of time that workers are exposed to vibrating tools.
HAVS Complications from Smoking
Smoking can intensify the symptoms of HAVS because of its detrimental effects on the circulatory system. It can greatly aggravate the vascular issues associated with HAVS by limiting blood flow to the hands and fingertips.
The reduced blood flow can increase the frequency of “white finger” seen in conditions like Raynaud’s Phenomenon. Smoking can also impair the body's ability to repair damaged tissues in the fingers. Quitting smoking is highly recommended as it can improve overall circulatory health and recovery.
Is HAVS Classed as a Disability?
HAVS can also be classed as a disability in the UK under certain conditions. According to the Equality Act 2010, a disability is defined as “a physical or mental impairment that has a substantial and long-term adverse effect on an individual's ability to perform normal day-to-day activities.”
HAVS must have a significant long term effect on the individual, meaning it has lasted or is likely to last more than 12 months. It must also limit the individual's ability to carry out daily activities including, reducing dexterity in hands, handling objects and performing precise movements.
If the individual meets this criteria, they are entitled to legal protection under the Equality Act 2010. This means the individual has the right to have reasonable adjustments made in their workplace, including changing work schedules and modifying equipment.
Industrial Injuries Disablement Benefit (IIDB): “Workers diagnosed with HAVS due to their occupation may be eligible for IIDB, providing financial compensation based on the severity of their condition.”
Health and Safety Obligations: “Employers are legally required to assess and manage risks associated with hand-arm vibration under the Control of Vibration at Work Regulations 2005, which is part of their duty to ensure employee health and safety as outlined in the Health and Safety at Work etc. Act 1974.”
Regulation and Legislation that applies to HAVS
The relevant legislation for managing HAVS includes the following:
Control of Vibration at Work Regulations 2005 This regulation requires employers to assess and manage risks associated with vibration exposure. It specifies exposure limits and requires employers to reduce exposure for affected workers.
Health and Safety at Work Act 1974 Under this legislation, employers have a duty to ensure the health and safety of their employees, including managing risks from HAVS by implementing control measures.
Management of Health and Safety at Work Regulations 1999 This regulation requires employers to carry out sufficient risk assessments and to implement preventative measures based on those assessments.
Industrial Injuries Disablement Benefits (IIDB) Scheme This scheme provides compensation for workers who suffer from HAVS, which is recognised as an industrial injury due to their occupation.
These regulations aim to protect workers from the effects of HAVS and to ensure a safe working environment. Employers must comply with these regulations to mitigate the impact on employees.
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