Movement variability in people experiencing chronic musculoskeletal shoulder pain compared to healthy controls: A cross-sectional study

Abstract

Chronic musculoskeletal (MSK) shoulder pain is a common condition that restricts people to execute activities of daily life. People experiencing pain move differently in terms of movement variability. At the upper extremity, differences in movement variability between persons with pain and healthy controls as well as the relationship between movement variability and pain intensity are unclear. This study aims to investigate the difference in movement variability at the glenohumeral (GH) and scapulothoracic (ST) joints during the performance of reaching tasks between participants experiencing chronic MSK shoulder pain and healthy controls, and to investigate the relation between pain intensity and movement variability. Inertial sensors were used to record 3D movements of the GH and ST joint. Only one GH joint movement showed more movement variability in participants with chronic MSK shoulder pain in the expected forward reach. Furthermore, more movement variability was seen in three different ST joint movements during the expected forward reach. Finally, three movements showed a correlation between pain intensity and movement variability. Movement variability differs in people experiencing MSK shoulder pain. Although there seems to be a trend towards greater movement variability at the shoulder in people experiencing pain, more research is needed.