The effect of handle angle on MAWL, wrist posture, RPE, and heart rate

In manual material handling tasks, the handle serves as the interface betwe en the human operator and the box (the materials). Handle angle design can affect both wrist posture and lifting ability. This study was designed to e valuate the effect of handle angle on maximal acceptable weight of lifting (MAWL), perceived whole-body exertion, whole-body workload, wrist posture, and perceived wrist exertion. The results indicate that handle angle had a significant effect on wrist posture and wrist rating of perceived exertion (RPE). A box with a 0 degrees handle angle induced the greatest ulnar devia tion and the highest wrist RPE. A 75 degrees handle angle induced the great est radial deviation and a relatively high wrist RPE. A 30 degrees handle a ngle resulted in the greatest MAWL and the lowest level of wrist RPE. Overa ll, these findings suggest that 30 degrees and 45 degrees handle angles can provide favorable coupling conditions for the cutout-type handhold contain er handle. Actual or practical applications include the ergonomic design of container handles for manual material handling tasks industry.