Development of anatomical dynamic model of shoulder joint and surrounding tissue

Abstract

The shoulder joint represents the most unstable and complex structure in all of human joints. Shoulder movement involves complex interactions between skeletal system and soft tissues. Understanding these mechanical interactions is important for improving the motor skill in sports and preventing shoulder disorders, such as a dislocation. Musculoskeletal simulation can reveal various mechanical information in human body as non-invasive tools. Several studies have reported that human parts were modeled using finite element method to analyze deformation of soft tissues, and modeled as rigid bodies in multi-body simulation system to reveal the dynamic motion behavior. However, soft tissues related to shoulder joint (e.g., joint capsules and rotator cuff) have not been previously modeled in dynamics simulation system. The aim of this study was to construct anatomical dynamic simulation model of shoulder joint and surrounding tissues by cadaveric specimens. The bones were modeled as rigid bodies using CT scanning of the single cadaver. The joint capsules and rotator cuff were modeled as spring-damper-mass system to connect rigid bone models. The result of dynamics simulation showed the detailed behavior of shoulder joint by contracting rotator cuff muscles.