Abstract: For the WMSDs prevention of construction workers,a method was worked out for assessing the risk of construction workers' trunk posture using mobile sensor. The back having a higher prevalence of WMSDs for construction workers was taken as research object. The built-in smartphone orientation sensors was used to collect data utilized to calculate the flexion-extension angle, lateral bending angle and rotation angle of the trunk posture. The risk of posture was assessed according to the relationship between the static angle and the maximum holding time given by ISO11226: 2000. The method was verified by the laboratory and on-site experiments. The results show that the worked out by the authors is effective and applicable to description and assessment of the construction workers' trunk posture.

Key words: construction workers, awkward posture, maximum holding time, smartphone, work-related musculoskeletal disorder (WMSDs), assessment of risk