Analysis of biomechanical stresses during drywall lifting

Constant lifting of massive and bulky drywall sheets creates overexertion h azards among drywall installers. The objective of this study was to gain un derstanding of the biomechanical stresses imposed on the workers while lift ing drywall sheets. A video analysis was performed to identify current dryw all lifting techniques. Computer simulations of these techniques for liftin g drywall sheets of 60, 80, and 100 lb were then conducted to estimate the biomechanical loadings on the workers. Four lifting methods were determined to be the most commonly used drywall lifting techniques. The University of Michigan Three-Dimensional Static Strength Prediction Program (3DSSPP(TM)) was used for the simulations. It was found that all four lifting technique s produced considerable biomechanical stresses at the workers' shoulders, t orsos, and hips. Only a limited percentage of the male population has suffi cient strength capability to perform the task. The estimated L5/S1 and L4/L 5 disc compression forces were consistently high, ranging from 655 to 1363 Ib for various loads and postures analyzed. Results from this study provide d evidence regarding the biomechanical stresses associated with drywall lif ting. Further studies are recommended to identify less stressful drywall li fting methods and to develop safe assistive devices to reduce overexertion injuries.