Conservative treatment of anterior shoulder luxation includes immobilization in internal rotation. This has been increasingly debated, but imaging techniques in supine position do not reflect the influence of gravity. To examine glenoid labrum dynamics, the shoulders of 15 healthy subjects were imaged in standing position at different (0, 15, 30) degrees of external rotation using the Upright MRI. The functional length of the anterior labrum was measured. Due to an increasing tension of the anterior capsule, functional labrum length increased the more, the more the humerus was externally rotated. The results underline the usefulness of the Upright MRI and support the concept of immobilization in the position of external rotation.