Among the devices and hand-tools that produce mechanical vibrations, two groups should be distinguished:

• Devices and hand tools that are designed to generate vibrations used in technological processes such as breaking, whipping and concentration.
• Devices and hand tools that produce vibrations as an additional but unwanted factor that degrades their performance.

Taking into account the division of mechanical vibrations due to the way of transfer into the body, the sources of vibrations in the work environment can be divided into:

• Sources of whole-body vibrations,
• Sources of hand-arm vibrations.

The sources of whole-body vibrations include:

• Floors, platforms, bridges in production halls and rooms where workstations are located.
• The ground near stationary, portable or mobile machines is a primary source vibrations such as rail traffic.
• Seats and floors of means of transport vehicles such as cars, tractors, buses, trams, trolley buses, railway vehicles, ships and aircraft.
• Seat and floor of construction machinery (eg for earthworks, foundations, compaction of soils).

The sources of hand-arm vibration mainly consist of:

• Manual impact tools with pneumatic, hydraulic, internal combustion or electric drive including hammers, rammers, concrete compactors, riveters, hammer drills and impact wrenches
• Manual rotary tools with electric, pneumatic, hydraulic or combustion drive including chainsaws and grinders.
• Manual oscillating tools with electric, petrol, hydraulic or pneumatic drive including grinders and saws.
• Control levers of machines and vehicles operated by hand.
• Technological sources such as work pieces held in the hands or guided by hand during grinding, honing and polishing.

Some hand tools classified as typical sources of hand-arm vibrations such as hammers and saws can generate vibrations with very high amplitude. These vibrations may be transmitted by the shoulders to the torso and head, which in turn can lead to excitation of resonant vibrations of internal organs. In this case, hand tools are not only sources of vibrations that act locally on the worker, but are also sources of whole-body vibrations.