###### Abstract  
The objective of this systematic review is to investigate the various approaches that have been undertaken in finite element analysis (FEA) of human-seat interactions and synthesize the existing knowledge. With advances in numerical simulation and digital human modeling, FEA has emerged as a powerful tool to study seating comfort and discomfort. FEA employs various biomechanical factors to predict the contact stress and pressure distribution in a particular seat design. Given the complexity of human-seat interaction, several modeling and processing steps are required to conduct realistic FEA. The steps of how to perform an FEA simulation on human-seat interactions, the different models used, the model mesh compositions, and the material properties are discussed and reviewed in this paper. This can be used as a guideline for future studies in the context of FEA of human-seat interactions. finite element analysis (FEA); seating comfort; body-seat system modeling: human model +  
and the object, which represents the (dis)comfort and points of maximum stress that can generate pressure ulcers. Although the FEM method has great potential in providing a means for computationally simulating real-world physical interaction between a human body and seat/bed, the computational cost of performing the matrix inversions on very fine and complex mesh structures is quite high. For this reason, another approach is to parameterize the seat/bed design for comfort by focusing on the pressure distribution as it is considered to have the clearest association with seat/bed comfort, and thus, parameters relating to the pressure distribution, such as peak pressure and contact area, have been used as indications of the comfort level of a seat/bed. The use of multibody biomechanical modeling and contact mechanics is considered to be a faster method than FEM for simulating the human body and seat/bed pressure distribution. Despite the recent advances in finite element methods, FEA of human-seat interactions remains challenging. This stems from the many complicated steps that need to be taken to appropriately model the geometrical and material properties of the different layers of the human body, e.g., skeletons, muscles, and skin. Once a suitable human model is obtained, appropriate modeling of the human-seat contact, representation of the boundary conditions, and experimental validation of the FEA results need to be addressed. To the authors' best knowledge, the existing commercial software do not offer a validated human-seat model. A few finite element models, such as THUMS [7], GHMBC [8], and PIPER [9], have been recently developed to study crash safety in the automotive industry. There are several other models presented in the literature for comfort/discomfort and pressure ulcer studies. However, there is no consensus on the level of detail, the different layers of the human body to be modeled, and the material properties of each layer. Moreover, the advantages and disadvantages of the different existing methods are not clear. One review paper [10] reviewed the different approaches used for FEA of human-seat interactions, but it was limited to pressure ulcer studies on the buttock and thigh area. Full-body studies, especially the important topic of backrest comfort, and a comparison of the different methods and their advantages and disadvantages have not been discussed. To address the above gap, the current study aimed to conduct a systematic review of the existing literature on FEA of human-body seat interactions to synthesize the existing knowledge on this topic. We investigated _what are main steps involved in FEA of human body-seat interactions to predict the static pressure distribution, and what are the different methods that have been used to approach each one of these steps_? By answering these questions via a systematic review, we generated a set of recommendations for conducting similar studies in the future. We also present possible future research directions.