Lifting Height as the Dominant Risk Factor for Low-Back Pain and Loading During Manual Materials Handling: A Scoping Review

OCCUPATIONAL APPLICATIONS There is an increased risk of developing low-back pain when lifting objects closer to the floor when compared to lifting at waist height. These results support the key message of “store-it-off-the-floor,” which small businesses can easily implement to identify and control lifting hazards in their workplaces. Since the majority of the workforce is comprised of small businesses, ergonomic solutions (e.g., store-it-off-the-floor) should be designed to take into account the special challenges small businesses often face when trying to implement musculoskeletal disorder prevention activities, such as limits on time, knowledge, and budget. TECHNICAL ABSTRACT Background: Manual materials handling is a common hazard for workplace injuries such as low-back pain. Although the risk factor of lifting height has been shown in the literature to be a large contributor to low-back injury incidence, currently there have been no attempts to consolidate this information into a form suitable for knowledge dissemination. Purpose: The purpose of this study was to summarize the effects of lifting height on low-back loading and the risk of developing low-back pain. Methods: Three electronic databases (PubMed, Scopus, and Ergonomic Abstracts) were searched to find studies that could document the effect of lifting at various heights on low-back loading. Results: In total, 35 studies had outcome measures that were included in the analysis and interpretation for this article. Lifting from the floor was reported to produce up to twice the amount of spinal loading as lifting from a more desirable location, such as elbow height. This evidence supports a focus on avoiding lifting from low heights: below the knee and especially from the floor. Lifting from the floor also magnified the deleterious effects of manual materials handling on workers with low-back pain symptoms, older workers, workers with knee osteoarthritis, and workers with a high body mass index. Conclusions: The results of this review support a knowledge dissemination campaign targeting lifting from the floor as both a method for hazard identification and as the basis of controls in workplaces with little ergonomics knowledge, or in small business.