Human is exposed to whole-body vibration either in sitting, standing or recumbent position. Many studies had been carried out to study the vibration responses and develop the mathematical modelling in sitting and standing vertical position. According to previous studies, the resonant frequencies of the human body were identified to be in the range of 4-6 Hz and 8-12 Hz in the vertical position. Recumbent whole-body vibration also plays an important role as many situations in our everyday life are related to recumbent whole-body vibrations such as riding a train, ambulance transporting a patient or even sleeping. However, the studies of recumbent whole-body vibration are very lacking. Therefore, the main objective of this study is to develop a mathematical model to identify the response when a human body is subjected to recumbent whole-body vibrations. In this study, a nine degree of freedom mathematical model was developed, and the responses of the body were analyzed using Matlab Simulink. The overall resonant frequency of the body was found to be 1.4 Hz. Meanwhile, the head and neck had two resonant frequencies, which were 1.3 and 3.28 Hz for the head, and 1.4 and 3.4 Hz for the neck. This newly developed mathematical model can be used as a fundamental model to predict the response of any recumbent whole-body vibration.