Abstract
Nonlinear systems are not susceptible to research with a reductionist approach. In this sense, the complexity theory provides an alternative approach to quantify the importance of contextual factors in patients with musculoskeletal pain. The use of positive (placebo) or negative (nocebo) contextual factors in the therapeutic setting could largely account for the non-specific component of treatment efficacy, directly affecting the quality of patients’ health-related outcomes (e.g., pain, disability, or satisfaction). In recent years, there has been a better understanding of the effects of contextual factors. However, the knowledge and awareness of them is limited and heterogeneous among physical therapists, reducing their translational value in the field of physiotherapy. The purpose of this essay is to describe the management of patients with musculoskeletal pain from the complexity theory perspective.