The Effects of Muscle Activity on Human Kinematics and Muscle Response Characteristics – Volunteer Tests for the Validation of Active Human Models

The purpose of this study was to provide biomechanical data for the improvement and validation of active human models. A drop test setup was developed for the measurement of dynamic soft tissue characteristics in dependence of the muscle activation state. The tests revealed different energy dissipation properties for relaxed and activated muscle tissue. For the investigation of the influence of muscle activity on human kinematics a low-impact volunteer pendulum test was designed. The posture maintenance of seated subjects was tested by frontal, lateral and rearward pendulum impacts to the upper torso. The kinematics was recorded with an optical movement analysis system and muscle responses were detected via EMG. Smaller displacements of the head and upper torso were observed in tests with pre-activated muscles. The obtained data were used in the validation of a finite element human body model (HUMOS).