IDENTIFYING POSTURAL HAZARDS WITH A VIDEO-BASED OCCURRENCE SAMPLING METHOD

In modern industry physical labour still plays an important role. Ofte n jobs cause workers to exert forces in an uncomfortable or unhealthy body posture. To analyse possibly hazardous postures a variety of meth ods are available. However, paper and pencil methods or tactile or inf rared-based posture measurements are not always feasible. At workplace s where interference with the task has to be minimized and where diffe rent postures have to be observed over a longer period of time this ca n best be done by video recording. The video tapes are then the basis of a posture analysis through occurrence sampling. In a field study th is method was applied in a fibre spinning area of a chemical plant. Tw enty day and night shifts were recorded by a stationary camera. Using occurrence sampling on the video tapes, 8130 postures were encoded usi ng the OWAS posture analysis system. For the evaluation of critical po stures the OWAS four-class-system was changed to a system using three zones, red, yellow, and green. The results of the analysis showed a po ssible health risk (yellow) due to hazardous postures of the back and head. This corresponded to questionnaire findings where 70% of the wor kers complained about lower back pain and 40% about neck and shoulder pain. From the video tapes the tasks causing the hazardous postures we re identified, and appropriate re-design measures were suggested. In s ummary, the study showed that a video-based posture analysis using occ urrence sampling is easy and time saving. From the video tapes not onl y hazardous postures but also the risk factors causing them can be ide ntified. Interference of the video camera with the task or the observe d workers is minimal. However, if the job requires the workers to move to different areas, multiple cameras have to be used.