Ergonomic Evaluation of Pruning in Simulated Greenhouse Conditions

Greenhouse is a space-efficient structure for farming. The workers stretch their bodies to perform operations away from the body and at different heights. The present study aimed to assess the physiological and postural discomfort because of the varied working heights and horizontal distances and also attempts to suggest suitable interventions to overcome them. The current study investigated the physiological and subjective measures of exertion while working at different heights (elbow height, shoulder height and above shoulder height) and horizontal distances (30, 45, 60, and 75 cm) with two different pruning tools under simulated laboratory conditions. All the physiological parameters and responses against different conditions were recorded from six male participants and analyzed as per experimental requirements. The outcome of the present study demonstrated that physiological cost and subjective measure of exertion varied significantly with the variation in heights and horizontal distances. Heart rate, oxygen consumption, energy expenditure, and perceived exertion were significantly higher “above the shoulder height” than elbow and shoulder height. Similarly, all the measured physiological parameters and Rating of Perceived Exertion (RPE) exhibited a gradual increase with increasing the distance from the worker’s body. The study also revealed a differential effect of tools used while performing the pruning work. Further, the multiple regression analysis helped to predict Relative Cardiac Cost from RPE and other evaluated physiological parameters. Overall, findings from the current study concluded that conventional pruning activities need workspace optimization and ergonomic intervention to select pruning tools and achieve the desired productivity with minimum Musculoskeletal Disorders (MSDs).