Ergonomic Evaluation of Manual Weeding Practice and Development of an Ergonomic Solution

Agricultural workers performing manual weeding are exposed to high risks of musculoskeletal disorders to the lower back. Hand weeding exposes workers to sustained static loading to spinal soft tissues, which can lead to the initiation of a cycle of inflammatory response. Assessment of injury risks and investigation of current and new methods of manual weeding are the focus of this study. Nine subjects (7 males and 2 females) participated in this study. Trunk kinematics were monitored while workers performed four weeding tasks using different methods; long- and short-handled weeding (hoe and weed Puller), hand weeding, and a newly developed “Eater”. The Eater consists of two conveyor belts working simultaneously in an intermesh design to simulate the pulling and grabbing action of the hands. Hoe weeding is considered a less hazardous alternative to hand weeding with regards to back injuries but, our results showed otherwise. The worker's sagittal position with the hoe weeding was not significantly different from the short-handled tool. Also, workers weeding with the hoe displayed the highest trunk velocities. On the other hand, the Eater showed promising results by significantly reducing biomechanical risk factors. However, productivity results are not as promising.