Modeling Hand Trajectories during Sequential Reach Movements in a Pulley Threading Task

Modeling of human motion is common in ergonomic analysis of industrial tasks and can help improve workplace design. We propose a method for modeling the trajectories of hand movements in the frontal plane during a sequential reach task that involves threading string through a system of pulleys. We model the motions as a combination of two consecutive phases, one where the hand is reaching between pulleys and another when the hand is engaged in threading a target pulley. Hand trajectories were modeled separately for each phase by fitting basis-splines to the observed data. Predicted trajectories were computed using task parameters as the input and compared to average trajectories from the 12 participants who completed the study.