The Effect of Handle Angle on MAWL, Wrist Posture, RPE, and Heart Rate

Abstract

In manual material handling tasks, the handle serves as the interface between the human operator and the box (the materials). Handle angle design can affect both wrist posture and lifting ability. This study was designed to evaluate 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° handle angle induced the greatest ulnar deviation and the highest wrist RPE. A 75° handle angle induced the greatest radial deviation and a relatively high wrist RPE. A 30° handle angle resulted in the greatest MAWL and the lowest level of wrist RPE. Overall, these findings suggest that 30° and 45° handle angles can provide favorable coupling conditions for the cutout-type handhold container handle. Actual or practical applications include the ergonomic design of container handles for manual material handling tasks industry.