ANALYSIS OF COMPLEX sEMG DATA IN AGRICULTURAL ERGONOMICS: AN ETSU and Murray state Collaboration

PI: Ken Silver, ETSU

Abstract:

SIGNIFICANCE. Musculoskeletal disorders (MSDs) are associated with hand harvesting of crops, due to repetitive motions, lifting or carrying of heavy loads, and working in awkward postures, especially flexion of the trunk. A paucity of research exists on tomato farmworkers. The available studies have estimated risk based on self-reports of injury and semi-quantitative measures.

BACKGROUND. In the summer of 2018, a 2100 sq. ft. tomato test plot was constructed at ETSU’s Valleybrook facility to study muscle activity in workers engaged in cultivation tasks, using surface electromyography. sEMG is an objective-quantitative tool, intended to yield a refined understanding of ergonomic health risks. The muscle load and fatigue induced on the anterior deltoid and upper trapezius muscles were measured in three tasks: driving stakes into the ground, tying of tomatoes to stakes, and hoisting of a 35-pound bucket full of tomatoes. The 15 participating tomato farmworkers were recruited through the longstanding partnership between East Tennessee State University (ETSU) and a migrant health center (Rural Medical Services). An amplitude probability distribution function (APDF) was used to assess the muscle load. Normalized root mean square amplitude levels were used to determine muscle activity.

PRELIMINARY RESULTS. Higher mean muscle activity recordings were observed in the stake pounding task compared to the two other tasks. Low and moderate levels of physical activity were found across all three tasks; only the tying task showed evidence of some vigorous activity. The three tasks showed a higher level of moderate to peak load compared to the static load on the anterior deltoid and upper trapezius muscles with highest levels showing in stake pounding task.