This slightly slackens the inferior fibres of the glenohumeral ligament, allowing an abduction of 90°. Combining abduction with 30° flexion in the plane of the scapula causes a delay in the tightening of the ligament resulting in a maximum abduction of 110°.
This slightly loosens the inferior fibers of the glenohumeral ligament, allowing for 90° abduction. Combining abduction with 30° flexion in the scapular plane causes a delay in ligament tightening, resulting in a maximum abduction of 110°.