Validation of a New Objective Function to Optimize Body and Barbell Trajectory During Snatch Weightlifting By Using Temporal Finite Element Formulation and Experimental Data

In this study, we present the optimum body and barbell trajectory by using combination of two well-known objective functions as total torque and total power for biomechanical model of weightlifter via minimax optimization and temporal finite element formulation. The results were validated using the experimental data, which has been acquired by infrared camera. The experimental and analytical trajectories and actuated joint torques were compared to determine the optimum objective function for total torque, total power and minimax combination of them. All dynamic parameters have been calculated based on the Lagrangian formulation and rewritten based on temporal finite element. The optimal body and barbell trajectory has been obtained using a new objective function as minimax combination of total torque and total power. The constraints were maximum tolerated torque as weightlifter physiology, extremum of joint angles as weightlifter anatomy and balance maintenance equations as balance of weightlifter. The experimental barbell and joints trajectories, velocities and accelerations have been acquired by using the markers on the athlete's body, infrared camera and motion analyzer system. The experimental actuated joint torques calculated by forward dynamics. It has been shown that the generated trajectory using the proposed objective function has better convergence to the experimental trajectory.