Real-time risk assessment for construction workers' trunk posture using mobile sensor

The construction industry is one of the industries with higher incidence of Work-related Musculoskeletal Disorder (WMSDs), which will have an impact on the health and life expectancy of construction workers, reduce production efficiency and cause much economic losses. The prevalence of low back pain for construction workers is far higher than that in other parts of body, leading to the main factors of lower back pain including the awkward posture and the holding time for the same work posture. In this paper, a approach which uses the built-in smartphone orientation sensor to collect data utilized to calculate the flexion-extension angle, lateral bending angle and rotation angle of the trunk is presented to identify and assess the risk of posture according to the relationship between the static angle and the holding time given by ISO11226: 2000. And the proposed method is verified by the simple working posture in labrotory. Results indicate that measurements of trunk flexions of a worker by smartphone sensor data are close to corresponding observation values and can identify and assess the risk factors that cause the low back pain of the construction workers. In addition, a real-time risk assessment system of construction worker' trunk posture based on crowding was proposed, which will be applicable for the WMSDs prevention, construction site management and worker training.