The Examination of Movement of the Glenohumeral Joint by a Bony Landmark for the Analysis of Throwing

Abstract

At present, there is no way to evaluate gleno-humeral joint using a motion analyzer. We examined the measurement of the movement of the gleno-humeral joint from the body markers and went on the movement analysis of the throwing shoulder. The body markers of the scapula were set at 5 places. The differences were examined in 3 different elevated positions combined with 4 different directions. The relation between the angle of the glenoid fossa and the minimally different points were measured in the horizontal plane and the scapular plane. The angle of the glenoid fossa in X-ray films was compared with the estimated angle from the body markers. Finally, the ball release points of the throwing were examined in cases with SLAP lesion. The minimum difference between bony landmarks and the markers in each position were the coracoid process and acromion. The dispersion in these 2 points of 95% confidence intervals was within the range under 4. At the ball release, the gleno-humeral joint was horizontally extended in cases with a SLAP lesion. It became possible that the movement of glenoid fossa was analyzed by choosing the acromion and coracoid process as landmarks of the scapula.