Muscle and joint-contact loading at the glenohumeral joint after reverse total shoulder arthroplasty

Abstract

The purposes of this study were to determine the contributions of each shoulder muscle to glenohumeral joint force during abduction and flexion in both the anatomical and post-operative shoulder and to identify factors that may contribute to the incidence of glenoid component loosening/failure and joint instability in the shoulder after reverse shoulder arthroplasty (RSA). Eight cadaveric upper extremities were mounted onto a testing apparatus. Muscle lines of action were measured, and muscle forces and muscle contributions to glenohumeral joint forces were determined during abduction and flexion of the pre-operative anatomical shoulder and of the shoulder after arthroplasty. Muscle forces i..