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Updated: Aug 19, 2026

Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
Measurement of trunk bending during work by direct observation and continuous measurement
A Burdorf1, J Derksen, B Naaktgeboren
1Institute of Occupational Health, Erasmus University Rotterdam, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
Abstract:
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.
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