title: Strengthening evidence for exercise advice in spondyloarthritis
Creators: name: Millner, JR
Publisher: name: University of Tasmania
Year: 2019

description: ‘Axial spondyloarthritis’ (axSpA) is a term describing a group of immune-mediated rheumatologic diseases - the archetypical condition being ankylosing spondylitis (AS). The diseases predominately cause pain and stiffness of the spine, and can lead to spinal fusion. Although they can now be well managed, they are not curable - and since the usual age of onset is early adulthood, can be associated with a high burden of disease. Exercise has long been considered an essential ‘cornerstone’ of management, with general recommendations about regular exercise included in all recognised management guidelines. However, significant questions remain regarding specific exercise type, dosage and safety, and how exercise prescription should be tailored to the individual for optimal effect. The first part of this thesis seeks to assess the current literature for exercise interventions in AS and provide guidance to health professionals, by the development of an evidence-based consensus statement. The process included systematic reviews, with meta-analysis where sufficient evidence was available, for the topics of: assessment; monitoring; safety; exercise type; physical activity; concurrent medications; setting and adherence. Specific recommendations were generated by an expert panel for each topic, and are presented as a framework which facilitates adjustment according to assessment findings, that is, an individually tailored approach. A further knowledge gap is around the role of exercise designed to improve muscle fitness, that is, strength, power, endurance or motor control in axSpA. Early findings suggest there are pathophysiological changes in muscles with axSpA and the lumbar paraspinal muscles are almost always symptomatic. Therefore, more information about morphology and pathophysiological changes (such as inter-muscular adipose tissue (IMAT)) of these muscles could inform future exercise trial design. The second part of this thesis presents an exploratory pilot study investigating the size, symmetry and quality of the paraspinal muscles in a cross-sectional sample of people with axSpA. The most important finding from the magnetic resonance imaging (MRI) measures, was that there was significant fatty infiltration in both multifidus and erector spinae muscles, with a distribution that was largely symmetrical and most prominent at the lower lumbar levels. These findings support the need to investigate interventions targeting paraspinal muscle fitness. In summary, the first set of evidence-based recommendations to guide exercise advice in AS, including important considerations such as safety, were developed. They are designed to be clinically useful, by incorporating a framework which can be adapted according to individual needs. Information on morphometric muscle changes, and associated strengthening (resistance) exercise trials, are an identified knowledge gap. The pilot study findings of increased IMAT in a symmetrical distribution in the lower lumbar paraspinal muscles, may contribute to improved understanding of disease, and support the concept of evaluating an exercise program designed to improve paraspinal muscle fitness in axSpA.