MEASUREMENT OF TRUNK BENDING DURING WORK BY DIRECT OBSERVATION AND CONTINUOUS MEASUREMENT

An observational method and a continuous measurement technique were simultaneously applied to record bending of the trunk during work. In a group of 16 workers performing dynamic tasks a significant correlation (r = 0.57) was found between the two methods. A similar result was observed among 14 sedentary workers (r = 0.62). Although significant correlations between direct observation and continuous recording techniques were present, large differences were found between data obtained from individual subjects. The results cast doubt on the validity of assessments of percentage of worktime with bent trunk at an absolute level using only one measurement method. It is suggested that greater consideration has to be given in future studies to the reliability of measurement of postural load due to trunk bending.