Evaluation of personal weight transfer devices in agricultural stooped work

Abstract

Of the many types of Work-related musculoskeletal disorders, low back disorders (LBDs) are the most prevalent, and alone are a major health and socioeconomic problem. While a tremendous amount of attention has been focused on manual materials handling (MMH), lifting, and whole-body vibration, the LBD risk factor of bending and twisting of the spine has been relatively neglected. Frequent and/or sustained bending of the spine, often referred to as tooped postures, are dominant in several jobs having very high reports of low back pain. In agriculture, harvesting the majority of fresh fruits and vegetables still require workers to assume stooped postures. Other agricultural tasks (e.g., hand weeding) and many construction tasks (e.g., rebar tying) also require the workers to assume stooped postures. Finding feasible interventions to reduce the likelihood for developing LBDs among workers who are exposed to prolonged periods of stooped work will result in substantial reductions in worker disability, lost work time, and medical and other compensation costs. A pilot laboratory study conducted by the PI has shown that several personal weight transfer devices (designed to transfer loads from the back to the hips and upper legs) show a promise in reducing muscular load on the back and provided an indication that these devices may be an effective and feasible approach for reducing the high prevalence of LBDs among workers who assume prolonged stooped postures. Hence, the specific aims for this project are: 1) Conduct biomechanical, controlled harvesting studies to investigate how personal weight transfer devices affect the musculoskeletal system, 2) evaluate design and comfort issues, as well as various practical concerns related to the use of personal weight transfer devices. Incorporate changes that address these issues and concerns into modified (field-ready) weight transfer devices, 3) conduct a field cross-over intervention study among strawberry harvesters to evaluate the effectiveness of the modified weight transfer device in reducing low back symptoms during harvesting. Demonstrate the devices' feasibility for harvesting other crops, and 4) if the previous aims show that personal weight transfer devices considerably reduce the loads on the low back and the self-reported low back symptoms during stooped work, disseminate the findings throughout the agriculture and construction industries to help in the efforts of controlling LBDs due to stooped work. The study focuses on the agriculture/forestry/fishing sector identified in the National Occupational Research Agenda (NORA); however, stooped work is prevalent in other industries, especially construction and mining. Hence, results of this study may be translated to help the construction and mining sectors. The aims of this study address several of the 17 priority research topics identified in the production agriculture/forestry/fishing sector, including: 1) reducing the number of unintentional injuries, 2) education/outreach to increase the knowledge of effective occupational safety and health interventions for agricultural workers, 3) development of better methodologies for exposure and morbidity surveillance in agriculture, and 4) intervention to reduce adverse safety and health events in migrant/seasonal farmworkers. Stooped work is performed in almost every state, and therefore, the implications of this study should translate to other regions that have crops requiring stoop labor (e.g., fresh tomatoes in Florida and tobacco in Southeastern states). (AU)