Altered upper limb motor behavior in breast cancer survivors and its relation to pain: A narrative review.

Breast cancer is the most commonly diagnosed cancer among women and many women suffer from persistent physical and psychological complaints following their cancer treatment. Altered motor behavior at the shoulder region and upper limb, that is, alterations in movement patterns, spatiotemporal movement characteristics and muscle activation patterns, is a common physical consequence of breast cancer treatment, that can have a clear impact on daily life functioning and quality of life. Furthermore, altered upper limb motor behavior is suggested to relate to upper limb pain, which is very commonly reported in breast cancer survivors (BCS). This review, prepared according to the SANRA guidelines, looks into the current understanding of alterations in motor behavior at shoulder and upper limb in BCS, by discussing the factors related to this altered behavior. In this, we specifically focus on the relation between motor behavior and pain. Results of our search show that cancer treatment modality is predictive for shoulder range of motion. Furthermore, single prospective studies show depressive symptoms, living alone, being non-white and low physical activity levels as predicting factors for reduced shoulder range of motion. Pain as factor related to altered motor behavior is only assessed in cross-sectional research, limiting its interpretation in context of being cause or consequence of motor behavioral adaptations, and on the underlying mechanism explaining their relation. It is concluded that studies which explain the mechanisms how and in which subgroup of BCS motor behavioral alterations are associated with pain at the upper limb, are necessary in future.