Analysis of Physical Workload and Problematic Postures among Manual Handlers of Traditional Milling Industries by Use of OWAS Method

For several decades, rice mill workers have carried out manual rigorous tasks in traditional rice processing units of India and suffering from severe postural hazards. In this study, videography of tasks of rice mill workers was done to analyze and observe different postures by the computerized OWAS (Ovako Working Posture Analysing System) method. Some complementary questions regarding work adjustment and health and safety were asked by using Likert 5-point scale. Along with this intra-observer reliability and OWAS risk indicator was also calculated. Selected tasks were loading, unloading, stacking, filling, etc; that were performed mostly with bent and twisted back posture. Thus, to determine the static physical stress by determining harmful postures and to avail corrective actions for improvement of the existing situation forty male respondents from seven different units (mean age, 29 years) participated. Altogether, a total of 1360 (680 from each) exposure interactions from two video assessments were analyzed and then classified under different OAC (OWAS Action Categories). From all observations, poor postures, that need corrective measures immediately, were found in the loading, unloading, stacking and filling of rice sacks. Whereas intra-observer reliability and OWAS risk indicator were found to be 88% and 695%. Therefore, OWAS was useful in evaluating the static physical workload by locating hazardous activities due to harmful postures and suggesting needed means to reduce postural stress.