Biomechanical Investigation of Empirical Optimal Trajectories Introduced for Snatch Weightlifting

The optimal barbell trajectory for snatch weightlifting has been achieved empirically by several researchers. They have studied the differences between the elite weightlifters’ movement patterns and suggested three optimal barbell trajectories (type A, B, and C). But they didn’t agree for introducing the best trajectory. One of the reasons is this idea that the selected criterion by researchers might not be appropriate. Therefore we build a biomechanical model based on inverse dynamic approach to evaluate each trajectory while considering a specific mechanical criterion. We calculate the optimal motion of each trajectory that minimizes the actuating torques by using dynamic programming approach. We solve an example problem for a specific weightlifter that lifts a 100 (kg) barbell. According to our criterion, we recommend the pattern type C as the best trajectory. The most important result of this simulation is the cost assigned to each trajectory which gives us the ability to evaluate the trajectories clearly. This method is an appropriate tool for coaches to examine each trajectory for any specific weightlifter and make a good decision for selecting the best trajectory.