physical therapy or physiotherapy, treatment of disorders of the muscles, bones, or joints by means of physical agents—heat, light, water, manual and electronic massage, and exercise. Stroke, arthritis, fractures, and nerve damage are common conditions treated. The type of treatment needed is prescribed by a physician and carried out by trained physiotherapists. The therapist attempts to prevent pain or further damage and may also train different muscles to compensate for ones that have been damaged. Whirlpool baths are valuable in treating injuries and chronic inflammatory conditions. Ultrasound and short-wave diathermy may be employed for some disorders. Massage (a passive form of exercise) provides stimulation of nerves and prevents muscular atrophy in body areas disabled by paralysis or rheumatic disorders. Active exercises are also prescribed as treatment for various conditions. Physiotherapy is important in sports, not only as part of the conditioning program but also in treating injuries.