A Model of Length Increases of the Pectoralis Major Muscle to Provide Rehabilitation Precautions for Patients after Mastectomy.

A common complication of breast cancer treatment is the development of shoulder stiffness on the affected side. Rehabilitation interventions exist, but scientific guidelines for safe early motion are lacking. A 3-dimensional model of the shoulder and the pectoralis major muscle was used to interactively generate the total muscle excursion during the simulated motions. From these simulation results it can be concluded that women can externally rotate the shoulder in isolation and fall within the "safe" guidelines for pectoralis major muscle increase. Flexion and extension can also be safely accomplished. However, combined motions, such as abduction with external rotation will fall outside of the "safe" region