These technologies enabled the precise capture of body movements and anatomical details. Based on this data, an anatomically accurate model of the human structure was constructed. The geometric components of the model include the torso, pectoralis major muscle, breast adipose tissue, arm bones, shoulder muscles and joints. The material properties of the shoulder straps were determined through rigorous tensile testing. A detailed contact model between the breasts and the sports bra was established to simulate realistic interactions. The experiment considered eight parameter levels for shoulder strap length to assess its impact. The finite element model was validated by comparing pressure values obtained from experimental pressure sensors placed on the shoulder straps and shoulders with those derived from the finite element simulations. This validation process ensured the model’s accuracy and reliability. Subsequently, the study utilized the biomechanical contact model to analyze the interaction between the sports bra shoulder straps and shoulder rotation.