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.

Get full access to this article

View all access options for this article.

References

Ayoub, M. M., Bethea, N. J., Deivanayagan, S., Asfour, S. S., Bakken, G. M., Liles, D., Mital, A., & Sherif, M. (1978). Determination and modeling of lifting capacity. NIOSH Grant No. 5R010H-00545--02, September.

Bonjer, F. H. (1962). Actual energy expenditure in relation to physical working capability. Ergonomics, 5, 467–470.

Borg, G. A. V. (1970). Perceived exertion as an indicator of somatic stress. Scandinavian Journal of Rehabilitation Medicine, 2, 92–98.

Coury, B. G. , & Drury, C. G. (1982). Optimum handle positions in a box-holding task. Ergonomics, 25, 645–662.

Donajkowski, K. L. (September, 1993). Back injury: Causes, prevention, treatment. Professional Safety, 21–26.

Drury, C. G. , Begbie, K. , Ulate, C. , & Deeb, J. M. (1985). Experiments on wrist deviation in manual materials handling. Ergonomics, 28, 577–589.

Drury, C. G. , & Deeb, J. M. (1986a). Handle positions and angles in a dynamic lifting task. Part 1: Biomechanical considerations.. Ergonomics, 29, 743–768.

Drury, C. G. , & Deeb, J. M. (1986b). Handle positions and angles in a dynamic lifting task. Part 2: Psychophysical measures and heart rate.. Ergonomics, 29, 769–777.

Drury, C. G. , Deeb, J. M. , & Hartman, B. (1989a). Symmetric and asymmetric manual materials handling. Part 1: Physiology and psychophysics.. Ergonomics, 32, 467–489.

10.

Drury, C. G. , Deeb, J. M. , & Hartman, B. (1989b). Symmetric and asymmetric manual materials handling. Part 2: Biomechanics.. Ergonomics, 32, 565–583.

11.

Hsia, P. T. , & Drury, C. G. (1986). A simple method of evaluating handle design. Applied Ergonomics, 17(3), 209–213.

12.

Lee, Y. H. , Wu, S. P. , & Hsu, S. H. (1995). The psychological lifting capacities of Chinese subjects, Ergonomics, 38(4), 671–683.

13.

NIOSH (1981). Work practice guide for manual lifting. Washington, DC: U.S. Department of Health and Human Services.

14.

Shih, Y. C. , & Wang, M. J. (1997). Psychophysical evaluation of handle diameter and handle angles. International Journal of Industrial Ergonomics, 19, 437–444.

15.

Snook, S. H. (1978). The design of manual handling tasks. Ergonomics, 21, 963–985.

16.

Tichauer, E. R. (1978). The biomechanics basis of ergonomics. Toronto: Wiley.

17.

Waters, T. R. , Putz-Anderson, V. , Garg, A. , & Fine, L. J. (1993). Revised NIOSH equation for the design and evaluation of manual lifting tasks. Ergonomics, 36, 749–776.

18.

Webster, B. S. , & Snook, S. H. (1994). The cost of 1989 workers' compensation low back pain claims. Spine, 19(10), 1111–1116.