What is vibration sickness? It is one of the most common occupational diseases

The fact that the use of vibrating tools has adverse effects on human health was not discovered until the early 20th century.
This disease or damage to health came to be called vibration sickness.

A few years earlier, however, a French physician, Maurice Auguste Gabriel Raynaud, described a phenomenon he observed in his patients.
These patients experienced coldness and tingling in the upper extremities, sometimes numbness, stiffness, pain, and a noticeable white discoloration of the last links of the fingers.
At the time, however, it was not entirely clear what was causing these complaints in certain groups of people.

Vibration sickness is the second most common occupational disease

Today, we know what vibration sickness is. It is clear that prolonged exposure to vibration has a negative impact on human health.

Vibrations are harmful to humans if they are between 20-400 Hz and a person is exposed to them for a long period of time, for example, in the course of their occupation.

Up to 2.5% of employees are exposed to vibration, which is one of the most common occupational diseases.

How is vibration caused?

Vibration is classified as a physical factor. It is the mechanical vibration, shaking or oscillation of a vibrating object at a high frequency. This movement is repetitive (periodic) and low amplitude.

Vibration is therefore generated by vibrating machinery (drill) and by shock-producing machinery (pneumatic hammer).

They can enter the environment under certain circumstances even when the machinery is stable, for example due to unbalanced mechanisms.

Physical aspects of vibration generation

As indicated above, vibration is caused by the oscillation of a solid object. This oscillation is called oscillation.

Thus, an oscillation is the movement of a material point (object) in which the system returns to its equilibrium position after being deflected out of the plane.

• oscillation - one movement of a material point (deflection from the plane and return to the initial state)
• oscillation period - the time it takes for a mechanical system to oscillate
• oscillation frequency - the number of oscillations per second

Harmful effect of vibration on the human body

Vibration has both positive and negative effects on the human body.

Vibration sickness is manifested by four basic aspects, namely damage to blood vessels, the nervous system, the musculoskeletal system (bones, muscles, joints) and distant organs.

The negative effect of vibration is classified on the basis of its transmission from the object to the person:

1. local vibrations - are vibrations that are transmitted from the vibrating object to the contact part of the human body from its vibrating part (drill, grinder, pneumatic hammer, jackhammer, chainsaw)
2. total vibration - is the vibration that is transmitted to a standing or seated person from a vibrating mechanism (heavy mobile equipment such as a tractor bus, combine harvester, trucks, platform)
3. special vibration - vibrations that are transmitted in a particular way and that cause intense shaking of the thoracic and cervical spine and head

Table showing damage to body parts by vibration at different frequencies:

Raynaud's phenomenon due to local vibrations

Raynaud's phenomenon is a disorder caused by damage to peripheral blood vessels in the upper limbs, and is also the most well-known vasoneurosis.
It arises from vibration-induced traumatic microangiopathy (damage to small blood vessels).

It is manifested by sensitivity of the hands to cold, stiffness of the fingers, finger pain, acral coldness, seizure bordered pallor to cyanosis of the fingers.

Neurological symptoms such as increased sweating of the hands, headaches, irritability, nervousness, sleep disturbances and hyporeflexia are also present.
Musculoskeletal changes are manifested by thinning of the bones in the fingers to the wrist.
Trophic changes in the hands may also be observed.

Stages of Raynaud's syndrome:

• Stage 1 RF - hypersensitivity of the hands to cold, objective cold fingers of the upper extremities, stiffness of the hands, tingling in the fingers.
• Stage 2 RF - seizure-like and well-defined white discoloration of the fingertips, marked tingling and numbness in the hands
• Stage 3 RF - blue (cyanotic) discoloration of fingertips, dryness, roughness, thickening and increased brittleness of skin and nails, swelling, necrosis

Interesting:
The Lewis-Prusik sign is an important diagnostic factor in Raynaud's syndrome.
When pressure is applied to the distal finger joint (nail bed area), blood is forced out of this area and turns pale.
After subsequent release of pressure, we observe the return of the fibrotic blood back (return of the pink coloration of the finger).
The interval of blood return to the capillaries is less than 2 seconds in a healthy individual.
In a patient with Raynaud's syndrome, this interval is significantly longer than 10 seconds.

HAVS syndrome is caused by local and whole-body vibration.

Vibration sickness, also known as hand arm vibration syndrome, is essentially a progression of RF.
It is caused by prolonged or excessive vibration.
The upper limbs are usually affected, as the name implies. Exceptionally, the lower limbs are affected.

Thus, vibrations acting on the hands and shoulders manifest Raynaud's phenomenon (white finger phenomenon), which comes in attacks.

The provoking factor of Raynaud's phenomenon is cold.

As the condition progresses with subsequent HAVS, permanent muscle weakness and numbness of the fingers occurs.
The syndrome progresses from the fingers to the whole hand, wrist to shoulder, which can result in difficulty in performing normal activities (buttoning, handling smaller objects) and permanent disability.

The condition is aggravated by the presence of pain, which becomes more intense if the provoking cause is not eliminated. This means that the evocative factor of the pain is the vibration mechanism and the work with it.

• Raynaud's syndrome
• vascular involvement of the hands, wrists and forearms (coldness, tingling)
• muscle weakness of the affected parts
• numbness and clumsiness in the upper limbs
• difficulty managing routine activities (handling smaller objects)
• pain evoked by the negative effects of vibration mechanisms

WBV syndrome as a consequence of vibrations of a specific nature

Raynaud's syndrome and HAVS syndrome are related or can be said to be two different stages of the same injury. WBW syndrome is different.

WBV syndrome (whole body vibration syndrome) is caused by whole body vibrations, but mainly of a special nature.

In this vibratory damage to the body, the symptoms of axial damage and peripheral vestibular syndrome dominate.

The patient has problems with maintaining balance and, therefore, with standing, initiating gait and walking.

Equally significant are pain in the skeletal muscle structures (axial apparatus), visual disturbances, disorders of the digestive system, disorders of the reproductive system (especially in women, menstrual disorders, miscarriages), mood disorders, insomnia and fatigue.

• Axial disorders (difficulty in standing, balance, walking)
• musculoskeletal pain and disorders
• visual acuity disorders
• digestive disorders
• disorders of the reproductive organs
• mood disorders

Prevention and treatment of vibration sickness

Vibration sickness is classified as an occupational disease, ranking second on the list of occupational diseases. This is why it is important to take care of protection and safety at work, especially when it comes to hazardous occupations (construction workers, foresters, farmers, professional drivers...).

Treatment of vibration sickness is possible. In more severe cases, the patient has permanent consequences that may not be fatal, but make the individual's life uncomfortable.

How to avoid the effects of vibration in hazardous occupations?

It is not possible to avoid the effects of vibration completely. If it were, we would never have heard of this disease.

However, it is possible, under certain circumstances and by following certain procedures, to minimise the number of affected employees and to reduce the symptoms and effects of the disease.

• Educating the employee about his or her job, the employee must be informed about the occupational hazards and how to minimise them
• the provision of appropriate protective work equipment for employees (clothing, gloves, etc.)
• ensuring a suitable working environment (thermal comfort in the workplace)
• observance of a working regime with alternation of work and necessary rest to avoid exceeding the permissible levels of vibration per person
• not overloading the musculoskeletal system
• ensuring that work equipment is of a satisfactory technical standard and that it is regularly maintained
• compliance with the production parameters as regards exposure to vibration at the permitted level
• ensuring preventive medical examinations in accordance with the applicable regulations

Interesting:
Work where the employee is exposed to vibration is not suitable for weaker individuals.
This mainly concerns people suffering from diseases such as diabetes, other endocrinopathies, polyneuropathy or persons with musculoskeletal disorders.

Treatment of vibration sickness

Treatment of vibration sickness is not possible or is not effective in a patient who continues to be exposed to these influences.

It is imperative that the treated individual be removed from the vibration-exposed environment before any therapy is initiated.

Interesting:
If the patient is not removed from the hazardous environment or is removed late, nerve regeneration may not be possible. In this case, the effects will be permanent.
Therefore, affected workers should consider whether to continue in the occupation.
A prohibition of activity may also be imposed by a physician after a focused examination of the patient, without the patient's consent.

Table of basic treatments: