HAVS. What is it all about?

Hand Arm Vibration syndrome is a diagnosis of a condition that occurs when an individual is exposed to vibration.

In the distant past vibration was thought only to cause Vibration White finger (VWF) but whilst that remains one of the diagnoses within HAVS it is not the only one.

From HSE  INDG175(rev3)

Why is hand-arm vibration an issue?
Regular and frequent exposure to hand-arm vibration can lead to two forms of
permanent ill health known as:

■ hand-arm vibration syndrome (HAVS); and
■ carpal tunnel syndrome (CTS).

Symptoms and effects of HAVS include:
■ tingling and numbness in the fingers which can result in an inability to do fine
work (for example, assembling small components) or everyday tasks (for
example, fastening buttons);
■ loss of strength in the hands which might affect the ability to do work safely;
■ the fingers going white (blanching) and becoming red and painful on recovery,
reducing ability to work in cold or damp conditions, eg outdoors.

Symptoms and effects of CTS can also occur and include:
■ tingling, numbness, pain and weakness in the hand which can interfere with
work and everyday tasks and might affect the ability to do work safely

The importance of realising the broad range of problems that can be experienced with vibration is clear. It comes down to, anything caused by vibration that resolves when the vibration is removed has to be considered as potential HAVS. This is initially reversible, but can become permanent.

Prevention:

Prevention is the key. Many industrial tools have indication on them of the amount of vibration they cause and the Law states:

The Vibration Regulations include an exposure action value (EAV) and an exposure
limit value (ELV) based on a combination of the vibration at the grip point(s) on the
equipment or work-piece and the time spent gripping it. The exposure action and
limit values are:
■ a daily EAV of 2.5 m/s2 A(8) that represents a clear risk requiring management;
and
■ a daily ELV of 5 m/s2 A(8) that represents a high risk above which employees
should not be exposed.

Assessment:

This is most commonly done as part of an assessment for Industrial Injuries Disablement Benefit (IIDB) as they have the necessary tests to confirm the diagnosis. These include the Purdue Peg Board, Finger rewarming test, vibrotactile and thermotactile tests, finger systolic blood pressure. The history is important and in many cases more routine tests such as nerve conduction accompanied by thorough examination also lead to the diagnosis.

Expert Opinion:

The only Experts who can comment on these cases are ones who have done the formal HAVS assessments, and that usually means ones who have assessed cases for IIDB. The diagnosis is often taken out of the hands of the Expert as an award of IIDB for one or more components of HAVS concludes the issue of diagnosis. An Expert who has not done assessments may claim that if it is not VWF it is not HAVS, or indeed that an award of IIDB does not mean that the claimant has  the condition; I have seen both on more than one occasion.

As always, the key is to ensure that your Expert is fully trained as an expert, preferably with the Cardiff University/ Bond Solon certificate (CUEW), but also that they actually see the condition your claimant has either in clinical practice or in quantity as medico-legal cases. This equates to Experts who opine on Whiplash mechanism or other types of RTA but their only exposure is a few medico-legal cases. They are not experts.

Mr R Scott-Watson BSc(Hons) MB BS LLB (Hons)(Open) CUEW DDAM FRCS(Ed)

https://rswmedicolegal.forensicandexpertwitness.co.uk/

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