An analytical approach to determine the in situ forces in the glenohumeralligaments

The purpose of this study was to use an analytical approach to determine th e forces in the glenohumeral ligaments during joint motion. Predictions fro m the analytical approach were validated by comparing them to experimental delta. Using a geometric model, the lengths of the four glenohumeral ligame nts were determined during anterior-posterior loading simulations and forwa rd flexion-extension. The corresponding force in each structure was subsequ ently calculated based on length data via load-elongation curves obtained e xperimentally. During the anterior loading simulation at 0 deg of abduction , the superior glenohumeral ligament carried up to 71 N at the maximally tr anslated position. At 90 deg of abduction, the anterior band of the inferio r glenohumeral ligament had the highest force of 45 N during anterior loadi ng. These results correlated well with those found in previous experimental studies. We believe that this validated analytical approach can be used to predict the forces in the glenohumeral ligaments during more complex joint motion as well as assist surgeons during shoulder repair procedures.