Based on the scientific evidence, physical therapy is generally safe when practiced by a qualified physical therapist; however, not every treatment program will work for all patients, and complications are possible. For instance, postoperative patients who are taking pain medications—especially pain medications administered transdermally or subcutaneously—may need to have their medications adjusted, and physical therapy can sometimes aggravate preexisting conditions. There have been reports of persistent pain and fractures of unknown origin associated with physical therapy, and physical therapy can sometimes lengthen the duration of pain or limit a patient’s range of motion.
Patients undergoing chest or another kinds of physical therapy may have an increased metabolic rate, heart rate, blood pressure and oxygen consumption. For some low-birth-weight premature infants and young child, physical therapy techniques such as passive motion and chest percussion therapy may increase the likelihood of bone fractures. In the elderly, walking backward during physical therapy may result in falls, which can sometimes have serious consequences.