Journal & Authors
The study, published in the International Journal of Occupational Medicine and Environmental Health (2026), was conducted by researchers Liu C, Zhang D, Si W, Li Z, Jiang S, Yin L, and Ren Z. The open-access paper is licensed under a Creative Commons Attribution (CC BY) agreement, making it freely available for distribution. The research focuses on biomechanical factors related to low back pain (LBP) in occupational settings, specifically examining how lumbar spine movement direction during lifting and posture affects spinal loading and LBP risk.
Study Design & Participants
This systematic review analyzed 10 studies published between 2017 and 2025, selected from databases including PubMed, Scopus, and Web of Science. The inclusion criteria required studies involving adult workers performing occupational lifting or posture tasks, with data on lumbar spine movement direction, biomechanical loading, or LBP outcomes. The studies originated from multiple countries, including the United States, France, Belgium, Iran, Switzerland, Brazil, and Malaysia. Participants ranged from 7 to 204 individuals, with most focusing on healthy adults, though some compared individuals with and without LBP. The research encompassed experimental laboratory studies, modeling/simulation, and observational cross-sectional studies, examining tasks such as squat lifting, stoop lifting, prolonged standing, and asymmetrical movements.
Key Findings
The review found that lumbar spine movement direction during work tasks significantly influences spinal loading and LBP risk. Biomechanical evidence indicated that squat lifting reduced shear forces at lower vertebral levels but increased overall musculoskeletal effort, while stoop lifting produced higher shear loads at the L5/S1 level. Lifting with a lordotic (inward-curving) spine posture elevated both compressive and shear forces. Individuals with LBP exhibited altered neuromechanical strategies, such as reduced lumbar flexion and increased pelvic compensation. Field studies linked repetitive manual handling and constrained postures to higher LBP prevalence, with asymmetrical movement, inadequate strength, and fatigue also contributing to injury risk. The authors emphasized that the direction and quality of lumbar spine motion during work-related activities are modifiable risk factors for LBP, suggesting that ergonomic interventions and behavioral training could help reduce spinal loading and prevent workplace-related back pain.
Limitations
The review acknowledged several limitations. Study designs varied widely, with differences in exposure definitions, outcome measures (e.g., compression forces, shear forces, LBP prevalence), and measurement tools (e.g., EMG, motion capture, modeling), making a meta-analysis infeasible. Laboratory studies, while controlled, lacked ecological validity, whereas field studies faced challenges with self-reported outcomes and variable environmental controls. Additionally, many studies had small sample sizes and focused primarily on healthy populations, limiting generalizability to broader working groups, including older adults or those with preexisting conditions. The authors noted that these factors constrain the ability to draw definitive conclusions about the relationship between lumbar spine movement and LBP risk.
Conclusion
The study highlights the importance of lumbar spine movement direction as a modifiable risk factor for occupational low back pain. While the findings suggest that ergonomic adjustments and training programs could mitigate spinal loading, the authors caution that further research is needed to address the heterogeneity in study designs and populations. The review underscores the need for targeted interventions to improve workplace ergonomics and reduce LBP risk among workers engaged in lifting and posture-dependent tasks.