Effect of high level grip-and push force and elevated arm posture on the zh-axis hand-arm impedance

In this study, we investigated the effect of grip forces, push forces and two arm postures on the biodynamic response of the human hand-arm system for vibration excitation along the forearm axis. Knowledge about the biodynamic response, in this case the mechanical impedance, is important for understanding the dynamic human-machine interaction and developing human models. The current state of research lacks information about the effect of high grip forces, push forces, and an overhead hand-arm posture on the mechanical impedance. In this study, we measured the mechanical impedance of 30 subjects with an electromechanical shaker in translational direction along the forearm axis. We investigated the influence of grip-forces (30 & 135 N), push-forces (50 & 110 N), arm postures (shoulder flexion 0° & 90°) as well as the respective effect sizes in the range of 10–500 Hz. The investigated factors have a significant influence (p