Evaluation of Tomato Farmworker Ergonomics using Electromyography

BACKGROUND AND SIGNIFICANCE. Various studies have identified physical risk factors for musculoskeletal disorders (MSDs) associated with hand harvesting of crops, due to repetitive motions, lifting or carrying of heavy loads, and working in flexed trunk postures. A paucity of research exists on ergonomic risks to tomato farmworkers. The available studies have estimated risk based on self-reports of injury and semi-quantitative measures. METHODS. A partnership between East Tennessee State University (ETSU) and a migrant health center (Rural Medical Services) has identified some of the occupational health needs of this population. With the aid of surface electromyography (sEMG), an objective-quantitative tool, a more refined understanding of ergonomic health risks for this population will be developed. The purpose of this study is to evaluate the muscle load and fatigue induced on the anterior deltoid and upper trapezius muscles during three tasks: driving stakes into the ground, tying of tomatoes to stakes, and hoisting of a 35-pound bucket full of tomatoes. Space for a mock test plot, where the study will be conducted, is available at the ETSU’s Valleybrook facility. Muscle activity recordings will be obtained from 15 tomato farmworkers. Spectral analysis and the amplitude probability distribution function (APDF) will be used to assess fatigue and muscle load respectively. A repeated measures ANOVA will be employed in the study. ANTICIPATED RESULTS. Findings of this study should show that localized muscle loading increases muscle fatigue. Neuromuscular demand should vary, depending on the type of task performed. Stake pounding may show a higher neuromuscular demand than the other tasks. AIM 1. Evaluate the magnitude of muscle activity during three simulated tomato-field tasks and measure the intensity of movement during the stake pounding task. AIM 2. Compare estimates of muscle fatigue and muscle load induced on the anterior deltoid and upper trapezius muscles during three simulated tomato-field tasks