Safe Lifting Limits for Pregnant Workers
Recently an employer asked for manual lifting guidelines for pregnant workers. The reason for their question was because a female employee who was in her first trimester of what appeared to be a healthy, normal pregnancy came to them with a note from her physician stating she should not exceed lifting 20 lbs for the remainder of her pregnancy. They’ve had several pregnant workers in the past who never brought such a note to them so they wondered if there were new weight limit guidelines or if was a physician that was being very cautious. Since this company had a number of positions that required manual moving and lifting of materials which were performed by male and female employees, having two or more female employees on weight restrictions for several months due to pregnancy would impact their scheduling and work assignments.
In researching this topic I came across two manual lifting guidelines for healthy pregnant workers. The first is from the American Medical Association (AMA) which has been in existence since 1984. The AMA guidelines define recommended weight limits “that healthy employees with normal uncomplicated pregnancies should be able to perform . . . without undue difficulty or risk to the pregnancy.” The table below
The second are guidelines recently proposed and released in a study published in the February issue of Human Factors. The recommended weight limits during pregnancy come from values derived from the Revised NIOSH Lifting Equation (RNLE) that had been adapted to include the anatomic changes that occur during pregnancy. According to the study, the most important biomechanical changes in pregnancy are:
- Changes in anthropometric characteristics
- Increased joint laxity and it’s potential to effect spinal stability
- Changes in balance control
The clinical guidelines are displayed in the picture below. It incorporates the recommended weight limits based on specific pregnancy assumptions. Please see the referenced study for details on all of their pregnancy considerations.
The authors of the study also provide a list of lifting task condition restrictions that would apply to the RNLE and in parenthesis apply to the above clinical guidelines for pregnancy.
*Please note that the study’s guidelines are proposed only and have not be formally endorsed or accepted by any medical organization as of this date.
The AMA guidelines and the proposed clinical guidelines based on the RNLE can serve as the basis for employers to evaluate the manual lifting requirements of specific tasks and/or positions to see if it exceeds the limits listed above.
References:
Waters, T., MacDonald, L., Hudock, S., and Goddard, D., Provisional Recommended Weight Limits for Manual Lifting During Pregnancy, Human Factors, February 2014, vol. 56, no. 1, pp. 203-214.