Kinematic and kinetic evaluation of a throwing model using motion primitives

A human model of a dynamic overarm throwing motion is evaluated in this work with novel motion primitives including determinants, key frames, and ground reaction force (GRF) profiles. The kinematic and kinetic data of overarm throwing from five subjects are used for motion primitives. The evaluation process uses combined qualitative key frames (picture-based) and quantitative analyses to capture the differences in the experimental and generated throwing motion. The model shows potential application in simulating human-like throwing strategies and humanoid motion planning and control. Significant correlation between the generated and experimental GRFs with R² = 0.90 and 0.82 were found for the right and left feet, respectively, and the total vertical GRF calculated from the model was approximately equal to the weight of the avatars. The generated right shoulder flexion, shoulder rotation, and right elbow flexion showed near perfect correlation with R² values larger than 0.90, while the right shoulder abduction, left hip abduction, and left hip rotation showed moderate correlations with R² values between 0.25 and 0.55. Due to strategy differences, the generated left hip flexion and left knee flexion showed weak correlations with R² values equal to 0.17 and 0.03, respectively.