Spondyloarthritis on the Move: Biomechanical Benefits or Harm.

PURPOSE OF REVIEW: Physical activity is beneficial in several diseases including spondyloarthritis despite mechanical stress being suggested as a trigger of disease onset or activity. Moreover, there is no clear answer as to where physiological loading of the joints ends and pathological overloading begins. The aim of this review is to provide an overview of what is known about exercise and biomechanical loading in spondyloarthritis. RECENT FINDINGS: Recent studies focused on the impact of mechanical loading in healthy individuals and spondyloarthritis patients, demonstrating an overlap between the groups and pointing out possible beneficial and detrimental activities. The discovery that several animal models of inflammatory arthritis are dependent on mechanical stress helps unraveling the involved molecular pathways. There is a knowledge gap between the beneficial effect of exercise reported in clinical trials and the harm seen in observational studies and animal models. Imaging studies provide a first step in joining these two opposites by highlighting a wide-ranging spectrum between healthy and diseased joints. Future research is warranted on specific interventions in well-defined patient populations and in animal models in order to understand the pathogenesis. Targeted exercise therapy and prevention should be considered specific goals.