Multidisciplinary evaluation of patients with hemophilia Spain, El Salvador and Bolivia. It aims to analyze and evaluate the skeletal muscle of patients affected with hemophilia Spain, El Salvador and Bolivia; describe deficit mobility and muscular strength, depending on the degree of injury, age, presence of inhibitors and the development of physical activity; identify the relationship between the functional deficit by clinical assessment performed with the use of validated measurement scales, the assessment of the degree of injury to specific scales of hemophilia; detect biomechanical alterations of the lower limbs and their impact on gait in patients with hemophilia; and evaluate the factors that influence the perception of illness and quality of life of patients with hemophilia.