The human body can be considered as a complex device that is dynamically distracted from its environment, while the various members of the body are "tuned" to specific frequency ranges. Whether these dynamic strains are perceptible and tolerated depends not only on their technical characteristics but also on the physical and mental state of man. How is the health and profitability of a worker's affected by the constant exposure to oscillations that may come from machines or general conditions in the workplace?