Ergonomic Postural and Biomechanical Analysis of Manual Weeding Operation in Agriculture Using Digital Human Models

摘要

The agricultural land of India is approximately 181.95 million ha (55.3% of entire area) where the majority of the landholding (i.e. 78.92%) are in the category of a small and marginal group. Weed control is one of the most challenging and labour-intensive operations in agriculture utilizing about 20% of human energy and 25% of labour requirement. Further weeds alone reduce about 50-70% in crop yields. Manual weeding operation is most widely used by small and marginal landholding. Manual operation is associated with different types of health hazards, such as musculoskeletal disorders (MSD), pain in various body parts, injury, etc., among farmworker due to ignorance of the capabilities and limitations (anthropometric and biomechanical characteristics) of the potential user group in the design of tools and equipment. Moreover, practising manual and wheel hoe weeding required more human energy, i.e. vary from 300 to 400 man-h/ha and 50 to 125 man-h/ha, respectively. The present study attempted to evaluate existing manual weeding using wheel hoe in the digital environment, using digital human modelling (DHM) for the prevention of work-related musculoskeletal disorders. The DHM has become commonly used for human-centred product design. The DHM tools have the potential to analyse and improve the product before it's ever launched. Therefore, the emphasis in this paper is to investigate the postural and biomechanical behaviour in manual weeding practices for the various user group (i.e. 5th—95th percentiles) of Arunachal Pradesh. The outcome of the postural analysis found to be more discomfort rating for the larger group of population (i.e. 50th-95th percentiles) for male workers in wheel hoe operation. Further, the compressive forces on L4-L5 lumbar spines showed higher values for wheel hoe for both male and female. A similar type of approach using DHM for others existing agricultural tools and equipment would improve human comfort, safety and overall productivity.