Rehabilitation after arthroscopic shoulder surgery is crucial to recovery. Patients who do not receive adequate therapy are less likely to recover their full range of motion. Most patients who undergo rehab also experience decreased shoulder pain and improved strength. The conventional method is immobilization of the shoulder for four to six weeks before rehabilitation is begun. A different school of thought is that patients benefit from earlier, more aggressive therapy. Most authorities call for an individualized approach, taking into account people’s conditions and other factors. Advocates of early immobilization believe that tissues require healing time before they are stressed. Studies have produced conflicting evidence. Research involving rats indicated that early, aggressive rehab enhances the strength of surgical repairs. A study of rats failed to reveal the same results. Patients sometimes suffer new rotator cuff tears during their rehab. Those undergoing therapy for repairs of large tears are especially vulnerable. Some therapists are concerned that starting rehab too soon, or doing it too strenuously, might heighten the risk. While this may seem logical, no studies have produced data proving a connection between aggressive rehab and the likelihood of recurring tears. Early, aggressive rehab typically features the use of passive-motion devices, which permit patients to move their arms and shoulders without exerting any effort. Proponents of early therapy cite research suggesting that it results in less shoulder pain and stiffness. Patients in one study also reported greater improvements in range of motion than those who began therapy later. In another trial, early rehab enabled patients to regain more function in their shoulders. Still, as one researcher noted, “no definite consensus exists” among authorities that the two methods produce significantly different outcomes. Whichever approach is employed, accepted protocols are followed. Physical therapists know when, and for how long, to carry out treatments and exercises. They weigh biological and biomedical factors in designing individual plans. Patients are guided through three stages of recovery: the initial phase, featuring considerable shoulder pain and inflammation; the “proliferative” period, a time of healing as new cells grow; and the “maturation and remodeling” phase. Some studies have attempted to determine whether active rehab or passive motion is better during each of the stages. Unfortunately, the evidence either way is not conclusive. In monitoring the progress of patients receiving rehab, therapists use tests created by the American Shoulder and Elbow Surgeons, and the University of California-Los Angeles. Other measurements are the Constant score; the Simple Shoulder Test; and the Disabilities of the Arm, Shoulder and Hand score. The tests assess patients’ range of motion, as well as the extent to which their shoulder function is restored. In deciding whether to pursue early and aggressive rehab, or start later with a more cautious approach, surgeons and therapists consider individual factors. The types of therapy, and when they are administered, vary according to patients’ ages and medical conditions. For some people, the tissues at the point of their repairs are too fragile for strenuous rehab. Others can start using passive-motion devices soon after surgery. Specially designed treatments are recommended for patients who sustain recurring rotator cuff tears.