This International Standard lays down a simple classification of motion- and vibration-sensitive human activity and task performance. The classification includes, and is intentionally limited to, volitional human activity and task performance known or presumed to be disturbed, degraded or disrupted by continuous, intermittent, transient, or repetitive oscillatory motion or vibration (including shock motion) of human beings, components of their task, or their surroundings. This classification applies only to volitional human activities and tasks, interference with which by motion or vibration is presumed to be mediated by direct mechanical intrusion, physiological (non-injurious) changes in the person affected, or reversible sensory impairment, distortion, or conflict caused by the motion or vibration. It does not extend to activity or performance reduction associated with disability due to motion- or vibration-related injury. This International Standard is intended specifically to be an aid in the formulation of standard guidelines for the evaluation of human whole-body exposure to mechanical vibration and shock in the frequency range 0,1 Hz to 80 Hz, when optimization of human activity and task performance in the mechanical environment is the main criterion of evaluation. NOTE 1 This International Standard also provides definitions of specialized terms, not defined in other standard vibration and shock vocabularies, that find a particular use in human biodynamics relating to task performance. It therefore supplements the biodynamical vocabulary in ISO 5805.