The Revised NIOSH
Lifting Equation (RNLE) Applications Manual guides users on how to use the RNLE, which is also available as a
mobile app. The app facilitates the calculations of RNLE for identifying the risk of low back disorders associated with manual lifting tasks. This 2021 manual is an updated version of the Applications Manual for the Revised NIOSH
Lifting Equation (RNLE) published in 1994. This update of the RNLE manual corrects typographical errors in the previous version and is reformatted to be searchable and 508 compliant. Specific changes are summarized on page xi. Publication of the RNLE in 1994 generated substantial interest among researchers and field safety professionals, and has contributed to improved risk assessments for manual
lifting jobs. A notable improvement included validating the task variables used to compute the Recommended Weight Limit (RWL). Additional studies validated the
Lifting Index (LI) as a measure of risk for workers performing manual
lifting jobs. Based on the findings from these studies, the LI calculated from the RNLE is well-regarded as a valid and practical tool for assessing the risk of low back disorders associated with most twohanded manual
lifting tasks. In addition, surveys have shown that certified professional ergonomists in the United States and many other English-speaking countries recognize the RNLE as an effective ergonomic risk assessment tool. The RNLE has contributed greatly to ergonomic risk assessments and prevention of work-related low back disorders. It has served as the basis for standard setting by the International Organization for Standardization (ISO) for their standard 11228-1 as well as the industry trade associations, Automotive Industry Action Group and Society of Automobile Engineers, for their Ergonomic Guidelines for Small Lot Delivery Operations. As a direct result of the wide application of the RNLE in assessing manual
lifting tasks, many other LI values, such as the sequential LI,
variable LI, and cumulative LI have been developed and validated by the research community. The 1994 version of the manual will be archived online by NIOSH as a permanent record. For citation of the RNLE applications manual, use the citation suggestion provided in the updated manual. Finally, the significant contributions of the late Dr. Thomas R. Waters and the late Dr. Arun Garg to the development of the RNLE and their efforts to validate associated outcomes of the RNLE are gratefully acknowledged. The RNLE is anticipated to continue serving workers and employers well by contributing to the prevention of low back disorders, which are common and costly musculoskeletal health problems in the workplace.
