The first is the extent of the damage. A shoulder that has dislocated for the first time without a tear of the labrum or fracture of the bone may not need anything more than a period of immobilization. The labrum is the dense fibrocartilage ring that is firmly attached to the shoulder socket. It makes the shallow socket deeper to help further stabilize the shoulder.

But if surgery is anticipated, then strict immobilization may be required. This period of rest will help the soft tissues lay down scar tissue to start the healing process of torn ligaments and other inelastic fibers.

The sling usually holds the arm in a position of internal rotation across the body. But at least one study tried immobilizing patients in a position of external rotation (the opposite direction). The results were just as good as if the arm had been internally rotated. And another study compared immobilization with no immobilization. They found no difference between the groups in terms of recurrence of dislocation and final outcome.

There's still much we don't know about the best treatment for a first-time shoulder dislocation. More studies are needed to find out if activity level, age, or gender makes a difference in how the arm is treated. We don't really know how long the sling must be worn for the best results (or if wearing one is even needed).

Until more details are known, it may be best to follow the standard treatment procedure advised by your health care provider.