Recognizing the viscoelastic safe area of work shoe sole in the sitting posture with vibration transmissibility in the vertical direction

Abstract Work shoe soles are a useful tool for decreasing the amplitude of vibration transmissibility to the human body for subjects exposed to foot-transmitted vibration (FTV) in the workplace. The main objective of this paper is to identify the viscoelastic safe area of work shoe soles in the sitting posture using a biomechanical model. To identify the model parameters, twelve young males participated in the experimental test. Moreover, to identify the viscoelastic parameters of the shoe sole model, three different work shoe soles, i.e., soft sole (Shore scale: A25), fairly soft sole (Shore scale: A42), and hard sole (Shore scale: A70), were used, whose mechanical parameters were extracted by establishing the experimental test based on vibration transmissibility. Afterward, the viscoelastic safe area of work shoe soles was determined based on vibration power absorption (VPA) for subjects exposed to vibration. The numerical simulation demonstrates that the soft shoe soles can decrease the maximum value of VPA up to two times compared to barefoot conditions. Furthermore, the maximum value of VPA in the hard sole is up to 14% more than that of the soft sole. Furthermore, the experimental test shows that the amplitude of vibration transmissibility to the hard sole is 15% more than that of the soft sole (p