Kinematic analysis of drywall lifting.
Pan-CS; Chiou-S; Long-D; Zwiener-J; Cantis-D
Advances in Occupational Ergonomics and Safety: XVth Annual Conference of the International Society for Occupational Ergonomics and Safety, Fairfax, Virgina, June 4 - 7, 2001. AC Bittner Jr, PC Champney, SJ Morrissey, eds., Washington, DC: IOS Press, 2001 Jan; 4:62-69
Drywall sheets are heavy and bulky. Depending on the thickness and size of the sheets, they can weigh between 55 and 200 pounds. Therefore, workers who constantly lift drywall sheets may be exposed to high risks for overexertion and fall injuries. The objective of this study was to quantitatively evaluate the kinematic stressors associated with lifting drywall sheets so that injury control strategies could be recommended. Twenty-eight construction workers (mean age = 35 +/- 9 years) with at least 6 months of drywall installation experience (mean experience = 9 +/- 7 years) participated in this study. Each subject performed a lift of a 4-foot by 8-foot drywall sheet. weighing approximately 55 pounds using one of four lifting methods: (1) vertical lift of the drywall, (2) horizontal lift of drywall with both hands positioned on the top of the drywall, (3) horizontal lift of drywall with both hands positioned on the bottom of the drywall, and (4) horizontal lift of drywall with one hand positioned on the top and one positioned on the bottom. The study was completely randomized with lifting methods randomly assigned to each subject. Workers' kinematic variables were quantified using a videobased motion analysis system (PEAK MOTUS). Kinematic variables included left and right elbow flexion, left and right arm/shoulder forward flexion, trunk flexion, left and right knee flexion, and left and right ankle dorsiflexion. Velocity and acceleration for each body part was also examined. These variables were used to examine workers' postures associated with each drywall lifting method. Analyses of variance (ANOVA) showed that the effects of different lifting methods were significant on all variables (p < .05) except for the left ankle dorsiflexion. The results of these analyses indicated that lifting methods 1 and 2 generated significantly less overexertion and fall hazards. An ongoing analysis is currently underway to examine kinetic variables (i.e., ground reaction forces). The findings from these quantitative studies will provide further understanding and focus for future research efforts on drywall-lifting, which can lead to the development of effective overexertion and fall injury prevention and intervention strategies.
Construction-industry; Construction-materials; Construction-workers; Manual-lifting; Manual-materials-handling; Materials-handling; Ergonomics; Injury-prevention
Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., Morgantown, WV 26505
Bittner-AC Jr.; Champney-PC; Morrissey-SJ
Advances in Occupational Ergonomics and Safety: XVth Annual Conference of the International Society for Occupational Ergonomics and Safety, Fairfax, Virgina, June 4 - 7, 2001