In recent years, functional assessment has become an alternative to the traditional medical method of evaluating disabilities. This discipline stands out because of its global approach towards the individual, analysing aspects related to the physical, social, emotional and behavioural dimensions of the patient. In contrast to subjective tests which offer only limited information to clinical professionals, biomechanical techniques are proposed as a complementary tool, being characterised by their objectivity and rigour in evaluation procedures. This allows the study of how pathology and pain affect the functional state of the patient, at the same time it serves as a tool for checking the effectiveness of the most appropriate treatments for the patient.