Development of a personalized musculoskeletal human shoulder

This work was supported by the project n. 38 Virtual human body model for prevention, therapy and rehabilitation of shoulder disease realised within the frame of the Program INTERREG V-A: Cross-border cooperation between the Czech Republic and the Federal State of Germany Bavaria, Aim European Cross-border cooperation 2014-2020. The realisation is supported by financial means of the European Regional Development Fund (85% of the costs) and the state budget of the Czech Republic (5%).The aim of this study is to contribute to the development of personalized musculoskeletal human shoulder model for the prevention, therapy and rehabilitation strategies. Namely, we participate in the development of the virtual shoulder model in the AnyBody Modeling System (AMS). This model consists of bones that are interconnected via kinematic joints, muscles with corresponding tendons and ligaments. The bones are considered as rigid bodies. Each muscle with corresponding tendon is represented with several virtual elements in the model that are usually referred to as lines of action. These lines are considered as hill-type models and allows for the active motion of the model as a whole. An important task in the model development is setting realistic muscle paths in order to predict accurate acting forces and moments. To achieve that, artificial obstacles are used in the AMS model to avoid unreal muscle shapes and excessive sliding. Namely, the torus obstacle method is used. It means that for each muscle line, tori obstacles are defined. The path is then given as a shortest connection of muscle attachments, closely wrapping the torus surface. Hence, the key issue of the model development is to define proper position and radii of each torus obstacle. These parameters differ in general for different individuals. The aim of this study is to develop methodology for setting the parameters of tori obstacles based on magnetic resonance imaging (MRI) of a particular shoulder. That is, patient-specific approach is adopted