Modeling Trend and Dispersion of Movements by an Alternative, Biokinematic Approach

Correct simulation of human movement behavior and its variability is one of the most challenging goals in Human Modeling. Likewise body shape and posture, dynamic properties of movements are essential for ergonomic workplace design. This paper presents an alternative approach, which is based on modeling empiric, kinematic measures rather than theoretical skeletal models. For this, experiments were carried out and the position of 15 anthropometric landmarks of subjects at a console workplace (e.g. air traffic controller) were captured, resulting into a total of 3.360 movements. Methods of Functional Data Analysis (FDA) were applied for a continuous analysis. It was found that a constant change of acceleration (or force) during the ballistic phase and a constant velocity during the goal-directed phase of the movement fits sufficiently for modeling position of effector (fingertip). For joint angles a constant change of acceleration during the whole movement was found to be sufficiently exact. Further FDA-Analyses hinted at an existing “general movement function” for the ballistic movement phase which is permanent and only modified in order to reach a specific target.