Modelling / Simulation

Document Type



This study aimed to investigate the effect of breast mass and motion on lumbar flexor / extensor moments during running. Kinematic and kinetic data were collected for a female participant running at 2.6 m/s. An MRI scan was used to calculate breast mass and centre of mass location. An OpenSim model was customised with two point-mass segments added to the torso to represent the breasts. Three model variations were constructed (combined breast and torso mass; separate breast and torso mass without breast motion; separate breast and torso mass with breast motion). Findings show that neglecting breast motion causes peak lumbar extensor moments to be underestimated by ~3.4%, compared with a combined breast and torso mass model. These results highlight the importance of including breast motion in female specific MSK models, during activities such as running.