Radiology allows to define etiologies of tendon injuries and authorize a most suitable treatment. For that reason, the use of the sonography has been developed from several years and has four main purposes to define the type of injury and to orient the treatment: to confirm the real existence of the tendon tear, to need the exact location the same one, to determine the gravity of the lesion, and finally, to evaluate its acute or chronic character. In this paper, we will try to define the normal pattern of the tendon and describe the more frequent lesions of the shoulder or the ankle: complete or partial tear, tendinopathy, dislocation and enthesopathy.