Revised NIOSH Equation for Manual Lifting: A Method for Job Evaluation

T he National Institute for Occupational Safety and Health (NIOSH) developed the Work Practices Guide for Manual Lifting in 1981 to assist safety and health practitioners in evaluating lifting and lowering jobs in the sagittal plane (USDHHS, 1981). Because the 1981 equation could only be applied to a limited number of lifting jobs, it was revised in 1991. The 1991 lifting equation reflects new findings, provides procedures for evaluating asymmetrical lifting jobs and objects with different types of hand-container couplings, and offers new procedures for evaluating a large range of work durations and lifting frequencies. The objective is to prevent or reduce the occurrence of lifting and lowering overexertion injuries and low back pain among workers.