Lower limb contribution to the dynamic response of the seated man

The aim of this study was to assess the effect of the lower limbs in transmitting vibration to the whole body of the seated man. Design of a biodynamic dummy, i.e. a mechanical system aimed at reproducing the dynamic behavior of the seated man and used to assess suspension seat efficiency, requires consideration of all parameters playing a key part in vibration transmission. To date, no study has been able to quantify the effect of considering knee- and pelvis-related movement on the dynamic response of the seat/subject system. The results of this study showed that, in the worst case, this effect plays about 15% part in this response. It was also demonstrated that lower limb effect is characterized essentially by additional damping which may be interpreted as associated with friction between subject and seat or internal damping in the joints.