Mohammad Reza Monazzam1, Esmaeil Shoja2, Seyed Abolfazl Zakerian1, Abbas Rahimi Foroushani3, Mohsen Shoja4, Masoumeh Gharaee4, Amin Asgari5. 1. Occupational Hygiene Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. 2. Department of Occupational Hygiene Engineering, Esfarayen Faculty of Medical Sciences, Esfarayen, Iran. e.shoja@nkums.ac.ir. 3. Epidemiology and Biostatistics Department, Tehran University of Medical Sciences, Tehran, Iran. 4. Department of Epidemiology, Esfarayen Faculty of Medical Sciences, Esfarayen, Iran. 5. Department of Environmental Health Engineering, School of Public Health, Ardabil University of Medical Sciences, Ardabil, Iran.
Abstract
PURPOSE: This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. METHODS: 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. RESULTS: Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. CONCLUSIONS: Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.
PURPOSE: This study aimed to investigate the effect of whole-body vibration and ambient lighting, as well as their combined effect on human discomfort, heart rate, and reaction time in laboratory conditions. METHODS: 44 men were recruited with an average age of 25.4 ± 1.9 years. Each participant was subjected to 12 experimental steps, each step lasting five minutes for four different vibration accelerations in X, Y, and Z axes at a fixed frequency; three different lighting intensities of 50, 500, and 1000 lx were also considered. At each step, a visual computerized reaction test was taken from subjects and their heart rate recorded by pulse oximeter. In addition, the discomfort rate of subjects was measured using Borg scale. RESULTS: Increasing vibration acceleration significantly increased the discomfort rate and heart beat but not the reaction time. Lack of lighting caused more discomfort in the subjects, but there was no significant correlation between lighting intensity with heart rate and reaction time. The results also showed that the combined effect of vibration and lighting had no significant effect on any of the discomfort, heart rate, and reaction time variables. CONCLUSIONS: Whole-body vibration is an important factor in the development of human subjective and physiological reactions compared to lighting. Therefore, consideration of the level of vibration to which an individual is exposed in workplaces subject to vibration plays an important role in reducing the level of human discomfort, but its interaction with ambient lighting does not have a significant effect on human subjective and physiological responses.
Authors: Saila Torvinen; Pekka Kannus; Harri Sievänen; Tero A H Järvinen; Matti Pasanen; Saija Kontulainen; Teppo L N Järvinen; Markku Järvinen; Pekka Oja; Ilkka Vuori Journal: Med Sci Sports Exerc Date: 2002-09 Impact factor: 5.411