A study on the difference of human sensation evaluation to whole-body vibration in sitting and lying postures.

The evaluation of vibration sensation is a problem which has large individual differences. In order to clarify the relationship between posture and psychological response, human sensation to whole-body vibration (from 2 to 11 Hz) in sitting and lying postures was evaluated by the semantic differential method, and the influences of posture on the evaluation were investigated by using the fuzzy measure. Furthermore, the paired t-test was used to test the significant differences in the results of evaluation between the two postures. The results were as follows: (1) Psychological responses of human beings to whole-body vibration were greatly affected by the postures. (2) Changes of the psychological responses in the lying posture were smaller than those in the sitting posture. (3) There were significant differences between sitting and lying postures in the evaluation results of physiological factor, psychological factor and synthetic evaluation (P < 0.025).