Validation of Triaxial Accelerometer to Continuous Monitoring of Back Posture at Sagittal and Frontal Planes in Workplaces

Musculoskeletal disorders are the most common work-related injuries and illnesses in workplaces. One of the important risk factors in creating low back pain during labor is undesirable postures. There are different methods for monitoring lumbar posture. The most important tools with high accuracy are direct measurement tools. The main aim of this study was to introduce and validate novel equipment in continuous monitoring of lumbar angles in the sagittal and frontal planes during work shift. A standard hand-held goniometer was used to calibrate an inclinometer (Virtual Corset). Depending on the type of the measurement plate, an inclinometer was mounted on a movable arm of the goniometer and angles of the two devices were adjusted; and the rate of the accuracy of the inclinometer was determined. Flexion angles were measured to be 0º to 95º, and lateral and extension angles were measured to be 0º to 45º. The error obtained from the inclinometer in the sagittal and frontal planes were approximately 1º and 0.05º, respectively. In addition, Cronbach''s alpha coefficient and regression line power was obtained to be 0.99. Despite Cronbach''s alpha being more than 0.75 and the high power of the regression line (0.99), VC is of sufficient validity for monitoring the angles of the lower back in a working shift. Additionally, the results of the study showed that the determined error was approximately identical to the error declared by the manufacturer.