Methods: A cross-sectional survey was conducted in South Africa, Ghana and Vietnam during 2012. It investigated water carrying methods and health status. Because areas of self-reported pain were correlated we undertook factor analysis of sites of reported pain, to interpret patterns of pain reporting. Regression analysis using Generalised Estimating Equations (GEE) investigated water carrying as a risk factor for general health and self-reported pain.
Findings: People who previously carried water had increased relative risk of reporting pain in the hands (RR 3.62, 95%CI 1.34-9.75) and upper back (RR 2.27, 95%CI 1.17-4.40), as did people who currently carry water (RR hand pain 3.11, 95%CI 1.34-7.23; RR upper back pain 2.16, 95%CI 1.25-3.73). The factor analysis results indicate that factor 1, ‘axial compression’, which is correlated with pain in the head and upper back, chest/ribs, hands, feet and abdomen/stomach, is associated with currently (0.30, 95%CI 0.17-0.43) or previously (0.21, 95%CI 0.01-0.42) carrying water. Factor 2, ‘soft tissue strain’, which is correlated with pain in the neck, shoulders/arms, lower back and hips/pelvis or legs, is marginally negatively associated with currently (-0.18, 95%CI-0.32 - -0.04) carrying water. The factor ‘axial compression’ was more strongly associated with carrying water containers on the head.
Conclusions: Participants who reported a history of current or past water carrying more frequently reported pain in locations most likely to be associated with sustained spinal axial compression in the cervical region. Given the fact that cervical spinal conditions are globally one of the more common causes of disability, our findings suggest that water carrying, especially by head loading is a major contributing factor in musculoskeletal disease burden in low income countries. Our findings support the proposed indicator for monitoring SDG6.1: “Percentage of population using safely managed drinking water services at home“ (our emphasis).