Burden, Body Region Distribution, and Ergonomic Stressor Correlates of Self-Reported Work-Related Injury Among Municipal Solid Waste Collectors in the Gambia: A Cross-Sectional Study of Two Urban Councils

Objective We examined self-reported work-related injury and its association with ergonomic stressors among municipal solid waste collectors in The Gambia. Methods In a 2020 cross-sectional survey at Brikama Area Council (n=98) and Kanifing Municipal Council (n=107), we modelled the number of anatomical regions with a reported injury over 12 months (0 to 9) against a six-item ergonomic stressor count (0 to 6), using Poisson regression with robust standard errors; binary outcomes used modified Poisson regression. The outcome is an injury-site count, not a musculoskeletal disorder measure. Reporting followed STROBE. Results Work-related injury was reported by 93.2% of workers (95% CI 88.9 to 95.9) and injury in three or more regions by 78.0% (71.9 to 83.2; mean 4.27, SD 2.18). Each additional stressor was associated with a 14% higher region count (adjusted count ratio 1.14, 1.09 to 1.20; p<0.001), with predicted counts rising from 2.26 to 5.03 regions across the stressor range and a stronger association at longer tenure (interaction p<0.001). Gradients were broad, not anatomically specific, strongest at the head (prevalence ratio 1.46, 1.20 to 1.78) and tooth (1.34, 1.12 to 1.60), regions with no plausible ergonomic mechanism. The E-value was 1.55 (limit 1.39). Conclusion A higher stressor count was associated with injury at more anatomical regions. Because exposure and outcome were self-reported at a single time point and equally strong at anatomically implausible and load-bearing regions, the association cannot be interpreted as an ergonomic dose-response effect. This identifies a heavily burdened, unstudied workforce and motivates measurement with validated instruments.