['The major complication in nonconforming total shoulder replacement (TSR) is glenoid loosening and is attributed to posteriorly directed humeral head translations. Whether the posterior translations observed clinically are induced by radial mismatch is unclear. The objective of our study was to explain the posterior glenohumeral translations observed clinically after TSR by determining the glenohumeral translation and contact force as a function of radial mismatch. We hypothesized that the posterior direction of glenohumeral translation during scaption would be related to the radial mismatch and that the joint contact force would increase as the radial mismatch increased.', 'A 6-degrees-of-freedom computational model of the glenohumeral joint was developed. We determined the muscle forces, joint contact force, and glenohumeral translation for radial mismatches from 1 mm to 20\xa0mm with the shoulder positioned from 20° to 60° of scaption.', 'As the radial mismatch increased, the contact location of the humeral head moved posteriorly and inferiorly. The middle deltoid force decreased by 3%, while the supraspinatus and infraspinatus muscle forces increased by 9% and 11%, respectively. The joint contact force remained relatively constant.'] Does nonconforming glenoid increase posterior glenohumeral translation after a total shoulder replacement?