Obesity is a growing health concern worldwide and musculoskeletal disorders (MSD) are the leading cause of injury, disability, and work-related sickness absence globally. A systematic literature review and meta-analysis was undertaken to investigate the effects of increased body weight on the biomechanical, physiological, and psychophysical responses to manual handling. Methods

A literature search was conducted on five electronic databases (EBSCO Health, SCOPUS, OVID (AMED), ProQuest, Google Scholar) that followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines. Studies were included if they investigated a manual handling activity comparing responses of obese/overweight adults to those with a healthy body weight. Included studies had to report on at least one biomechanical, physiological, or psychophysical outcome measure. The Joanna Briggs Institute (JBI) Critical Appraisal Tool was used to assess risk of bias (RoB) and methodological quality. A narrative synthesis of the findings was conducted and where possible, a meta-analysis was performed using random-effects models. Results

Eighteen cross-sectional studies met the inclusion criteria. Participants were predominately male (22% female) and were primarily classified into obese, overweight, or healthy body weight based on their body mass index (BMI). A task involving symmetrical box lifting was the most frequently performed activity. Pooled estimates of effect sizes suggest obesity increases the horizontal reach distance when lifting, and repetitive lifting leads to higher heart rates compared with healthy weight participants. There was moderate evidence of increased moments and compression forces in the lower spine. Factors unaffected by obesity were knee flexion and perceived estimates of the maximum acceptable weight of lift (MAWL). Conclusions

Differences in the kinematics and kinetics of lifting between obese or overweight handlers and those of a healthier weight, suggest that approaches to preventing and managing work-related musculoskeletal conditions should consider a worker’s body weight when designing workplaces, work practices, and training. To develop appropriate interventions, more high-quality studies are needed involving a range of industry and service sector handling tasks.