The machine that generates ultrasound is composed of a transmitter head and a current generator, and produces an output power of less than three watts. The treatment generally lasts a maximum of ten or fifteen minutes, and there are two possible ways of application: with the fixed head or the moving head. The first mode is used when the area to be treated is rather limited, such as a calcaneal spur; the second way, instead, is used for less circumscribed areas. The fixed head is blocked and held firmly by means of a mechanical arm, while the moving head, also called the massage head, requires the physiotherapist to slide the handpiece over the patient's skin, possibly rubbing it. Ultrasound is particularly effective for the treatment of capsulitis, tendonitis, bursitis, arthrosis, organized hematoma, joint inflammation, scar tissue, inflammation and periarticular calcifications, especially in the first phase. To give an example, several studies show that thanks to the application of ultrasound, the tibia fracture heals in a time reduced by forty percent compared to the norm.The contraindications, vice versa, are especially valid for varicose veins, articular prostheses, osteoporosis with high turnover, neoplastic tissues, thrombophlebitis and pregnancies, as well as presence of fragments of metallic nature. Thanks to ultrasound therapy, osteopathy and physiotherapy allow to solve various disorders in a simple and rapid manner. The approach turns out to be decidedly sweet, and naturally puts the respect of the entire anatomical structure first. For what concerns the whiplash, for example, the ultrasound intervenes on the area subject to an unexpected and abrupt shift, and solves the problem without painful treatments.The application techniques are essentially two: immersion or by contact. The first case is used when the areas to be treated are very painful or too small: the organ affected by the pathology is immersed in water at a temperature of thirty-seven degrees. The technique for contact, however, involves the use of electrodes, mobile or fixed, which come into contact with the skin, separated - if necessary - from a gel). For the contact mode the times range from a minimum of five to a maximum of ten minutes, while for the application of the dive mode it takes at most fifteen minutes (but care must be taken to avoid that the water temperature drops: in that case, the effectiveness of the therapy is reduced). Although the positive effects of ultrasound in physiotherapy are physically proven, it should be noted that the actual efficacy, in the presence of bone, muscle or tendon disorders or bruises, inflammations and fractures, depends on several factors, which can not always be quantified. We refer, for example, to the frequency of application and the number of sessions, to the correctness of the modalities and to the frequency of the waves.