Affiliations: Division of Safety Research, National Institute for Occupational Safety and Health, Morgantown, WV, USA
Corresponding author: Christopher Pan, Dcvision of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd., MS-G800, Morgantown, WV, 26505, USA. Tel.: +1 304 285 5978; Fax: +1 304 285 6047; E-mail: [email protected]
Abstract: Voluntary body movement can import a perturbation to the postural stability/balance of a human body. Heavy manual material handling such as drywall lifting may increase this perturbation. The objective of this laboratory-based study was to quantify workers' postural stability while lifting drywall sheets through kinetic and kinematic analyses, and to identify the drywall lifting methods that caused the least perturbation on workers' balance. Sixty male construction workers participated in this study. A simulated drywall-lifting workstation was built and all subjects performed one of the four randomly assigned lifting methods. Kinetic and kinematic measurements were synchronized and collected using a piezoelectric force platform and a five-camera motion analysis system. Both center-of-pressure (COP) and center-of-mass (COM) data were analyzed to assess workers' postural stability. Univariate analyses and principal component analyses (PCA) were used to analyze 13 COP-based and 21 COM-based variables. Results from the univariate analyses and PCA significantly indicated that the three horizontal lifting methods created less perturbation than the vertical lifting method. Based on the results of this study and prior studies, it is concluded that horizontal lifting with both hands on top of the drywall appears to be the best work practice to reduce manual drywall handling hazards associated with fall potential and overexertion injuries.
Keywords: drywall, lifting, kinematics, kinetics, center-of-pressure, center-of-mass, construction