Muscle moment and angle of hip, knee and ankle joints in a seven- link model of backpack sprayer operator

Background and Aim: Carriage of backpack sprayers is an inevitable part of agricultural operations that increases the risk of injury along with undesirable changes in walking mechanics. The purpose of this study is to formulate the muscle moment changes in the hip, knee and ankle for the backpack sprayer operator body. Methods: In this study, a seven-link sprayer operator model is designed and the moment changes in the hip, knee and ankle joints are evaluated. Data are obtained using Plot-digitizer software. Excel software is used to fit the third degree curve on the data. Results: In the hip joint, the moment is reduced by changing the angle from zero to 15°. At the end of the swing phase, the moment applied to the hip joint increases with increasing the angle up to 30°. In the beginning of the swing phase, the knee joint starts to open at -55°. At the end of the swing phase, the knee joint releases up to -5 ° and the moment applied to the knee joint increases slowly. The moment applied to the ankle joint increases by changing the ankle angle from -7.5° to 7.5°. Conclusion: According to the results of this study, amount of moment changes of hip, knee and ankle joint affect the force applied to the backpack sprayer operator body. With the knowledge of the moment changes of joints, practical solutions can be provided to reduce amount of damage to these joints.