Biodynamic modeling of hand-arm system to predict vibration transmission along with hand gripping force

Aiming at the problem of hand and arm vibration, a hand-arm model is proposed to calculate the vibration transmitted to the hand and arm by the steering wheel of a forklift with different gripping forces. The model consists of the shoulder, upper arm, forearm, and hand, connected by joints with stiffness and damping. The hand model consists of a palm and five fingers, with the distal, middle, and proximal ends of each finger connected by rotating joints. Moments are applied to the joints of the hand to simulate the active muscle forces of gripping the handle. The model material parameters are adjusted to match the contact pressure and vibration of the hand and arm when gripping the handle reported in the literature. The calibrated model is then applied to predict the vibration transmission of the arm system of a working forklift steering wheel. The results show that the established model considering gripping forces and hand-handle contact conditions can predict the vibration transmission of the vehicle driver’s arm system.