Breast cancer is the most frequently occurring cancer, assuming that it accounts for 29% of all new cancers in women (European Cancer Information System). The number of long-term survivors is increasing rapidly due to improving accuracy of the detecting methods, the early diagnosis and advances in cancer treatment. The International Consortium for Health Outcomes Measurement Initiative described upper limb (UL) function as the health outcome that matters most for breast cancer survivors (BCS). 50% of BCS at 6 months post-radiotherapy suffer from of decreased UL function, i.e. difficulties in performing activities of daily living with the upper limb. Patients experiencing UL dysfunctions and other problems are less likely to be physically active. Given that physical inactivity is associated with an increased risk of mortality after breast cancer, taking away the barriers to physical activity (e.g. UL dysfunctions) is very important. Identifying these factors contributing to chronic UL dysfunction is important in terms of identifying targets for prospective evaluation and specific treatment approaches at specific time points during breast cancer treatment. There is a need to rethink the follow-up strategy (besides the treatment of the cancer itself) and develop a clinical care pathway consisting of multifactorial screening instruments to identify women and men who are in need of extra rehabilitation efforts and specific rehabilitation goals to alleviate symptoms and side effects experienced by breast cancer survivors. This clinical care pathway should cover all aspects of the International Classification of Function, Disease and Health (ICF), a biopsychosocial framework that conceptualizes a person's level of functioning and bodily structures, activity and participation and contextual factors (including personal and environmental factors). The present study aims to identify the factors, during and after breast cancer treatment, contributing to persistent Upper Limb (UL) dysfunctions.