Provisional Recommended Weight Limits for Manual Lifting During Pregnancy

Abstract

Objective The National Institute for Occupational Safety and Health (NIOSH) Revised Lifting Equation (RNLE) was adapted to derive recommended weight limits (RWLs) for pregnant workers and to develop corresponding guidelines for clinicians. Background In the past three decades there has been a large increase in the number of women employed outside the home and remaining in the workforce during pregnancy. Practical authoritative guidelines based on accumulated evidence are needed to inform allowable work activity levels for healthy pregnant workers. Method Empirically based lifting criteria established by NIOSH to reduce the risk of overexertion injuries in the general U.S. working population were evaluated for application to pregnant workers. Our evaluation included an extensive review of the literature linking occupational lifting to maternal and fetal health. Decision logic and supporting literature are presented, along with computational details. Results Provisional RWLs for pregnant workers were derived from the RNLE, along with guidelines for clinicians. The guidelines advise against pregnant workers lifting below midshin and overhead. Conclusion Based on our review of the available evidence, we present lifting thresholds that most pregnant workers with uncomplicated pregnancies should be able to perform without increased risk of adverse maternal and fetal health consequences. Except for restrictions involving lifting from the floor and overhead, the provisional guidelines presented are compatible with NIOSH lifting recommendations adopted in the early 1990s for the general working population. Application Implementation of these provisional guidelines could protect millions of female workers in the work-place from fetal and maternal lifting-related health problems.

Clinical guidelines for occupational lifting in pregnancy: evidence summary and provisional recommendations

“…Details on the decision rules applied in the development of these provisional guidelines and the technical aspects of the RWL computations are available in a companion paper. 66 …”

Assessment of manual material handling in a tile and ceramic factory using the National Institute for Occupational Safety and Health‎ equation in 2016

“…The RNLE has been introduced as a useful tool for the estimation of exposure to biomechanical stressors to low back pain and LI is a scale of biomechanical stressors for low back pain caused by lifting and lowering of loads in sub-tasks and CLI is an estimate of the stressors associated with all tasks. In fact, LI and CLI showed a significant exposureresponse relationship for low back pain (19)(20)(21)(22). CLI for jobs (in the range of 3.34-5.99) in all three production lines showed that these jobs are physically stressful for all healthy workers.…”

“…As CLI values in all three product lines exceeded 3 (high-risk), the load lifting was very stressful and there was an increased risk of occurrence of low back pain caused by lifting loads for nearly all of the work forces. Researchers have reported a significant relationship between the risk of occurrence or prevalence of LBP, and LI or CLI of greater than 1.0 (20,(23)(24)(25). In comparison with CLI values of less than 1.0, odds ratio of selfreported LBP has been reported as 5.1 to 6.5 for CLI > 2.0 (26).…”

Evaluation of the Impact of the Revised National Institute for Occupational Safety and Health Lifting Equation

“…Additionally, several researchers proposed procedures to improve the reliability and quality of the measurements needed for using the RNLE (Lu, Waters, Werren, & Piacitelli, 2011; Okimoto & Teixeira, 2009; Waters, Lu, Werren, & Piacitelli, 2011). A number of studies added recommendations on patient lifting and lifting by pregnant women (Waters, Baptiste, Short, Plante-Mallon, & Nelson, 2011; Waters, MacDonald, Hudock, & Goddard, 2014). Two new variations were proposed for computing the LI (i.e., sequential LI and variable LI) for jobs involving rotations and variable lifting, respectively (Colombini, Occhipinti, Alvarez-Carsado, & Waters, 2013; Waters, Lu, & Occhipinti, 2007).…”