Vibrating objects may cause the whole body, or only parts of it, to vibrate Vibration may be transmitted to operators by direct mechanical paths or through several flanking paths. Example of head-seat transmissibility of a sitting subject, either leaning against a backrest or without using the backrest Figure 5.9 from K.Kroemer 1994 Human Responses to Vibration Chain saws pneumatic compactors, and electric hand tools, transmit vibrations to the hands and arms and are often responsible for cumulative trauma disorders. Vibrations from tools can be absorbed by cushioned seats, foot restraints, handholds, and mountings. Vibration may affect performance either by modifying perception, blurring visual images of dials and indicators, or affecting control movements. Table 5.9 shows some effect of vibration.
Excessive vibration can be unpleasant, painful, and even hazardous.
However, used improperly, light can annoy, distract, affect our performance, and even blind us. Table 5.12 gives the recommended illuminances for Generic types of activities in interiors.