Vibrations are oscillations emanating from machines due to imbalances and excitations of the engine. These vibrations can be transferred via contact areas to the human body. Depending on the position of the contact area Wholebody-Vibrations (WBV) are differentiated from Hand-Arm-Vibrations (HAV). In the first case vibrations are transmitted viathe feet, the back or the posterior into the human body. In the latter case the transmission goes via the hands, such as in the case of using hand-operated powered tools. Depending on the intensity, duration and frequency of the exposure to wholebody-vibrations medical consequences can include (chronical) back pain right up to the impairment of the spinal column. Long-term exposure to hand-arm-vibrations can cause regenerative as well as degenerative disorders, e.g. damages to bones and joints, circulatory or neurological disorders.
To protect employees from hazards due to exposure to vibrations, the European Directive (2002/44/EC) was issued in 2002, which was transposed into national law as the Noise and Vibrations Occupational Safety and Health Ordinance (LärmVibrationsArbSchV).
Therefore the Federal Institute of Occupational Safety and Health (BAuA) focuses on implementing this ordinance in practice. This includes the measurement and assessment of hazards caused by the exposure to vibrations, as well as technical measures for protection and mitigation to comply with exposure action values. The main focus of the institute's activities is on the Hand-Arm-Vibrations (HAV), and there on specific technical measures to protect against and mitigate vibrations. The primary objective is to avoid, prevent or at least reduce exposure of employees to vibrations at workplaces and by applying vibration control measures by design. Therefore reducing vibrations at source is of prime importance followed by measures to minimize transmissions of vibrations. Finally, measures to isolate the source of vibrations from the employee need to be considered.
Besides putting the LärmVibrationsArbSchV into practice, practical guidance manuals regarding Wholebody-Vibrations and Hand-Arm-Vibrations have been published.
In addition, a national pre-standard DIN was published in 2012 including a user-tool for the evaluation of shock containing Wholebody-Vibrations. The tool provides a risk assessment for possible damages to the spinal cord by the use of FEM (finite element method).