An Investigation of the Effect of Hand-Arm Posture and Grip Force on Vibration Transmission Rate of Human Hand-Arm System

Agricultural machinery is important for agricultural production. But the action of operating this machinery will inevitably produce the hand-arm vibration, thereby posing a threat to operators’ health. The study of the vibration transmission rate (VTR) of the hand-arm system will be conducive to reduce the harm. However, there is a lack of research that focuses on Chinese people. Based on it, the purpose of this study is to investigate the VTR of the human hand-arm system in China. A self-developed test handle was utilized to measure the VTR of the hand-arm systems of seven Chinese adult males under different conditions of two hand-arm postures and three grip forces. The results demonstrated that when the vibration frequency was less than 40 Hz, the VTR of the hand-arm system at the elbow angle of 90º was significantly higher than those at the elbow angle of 180º. But when the frequency was higher than 40 Hz, the hand-arm posture appeared to have no significant effect on the VTR. Furthermore, within a specific frequency range, the increase in grip force would result in the more effective transmission of vibration energy to the hand-arm system. This study not only provides a reference for protecting the occupational health of agricultural machinery operators, but also contributes to the design and optimization of agricultural machinery.