All patients (hip and knee) upon admission to the Orthopedic Department of the DRS (Rizzoli Sicily Department), throughin the pre-operative setting will undergo an assessment of mobility level, dynamic stability and co-ordination: Test UP and GO, Il Four Square Step Test, Stabilometric Analysis. After admission to the DRS Rehabilitation Medicine Department, hip and knee will receive an evaluation, which is currently used, consisting of: History of fall risk through multidimensional assessment, Compilation of ICF(International Classification of Functioning, Disability and Health) and Barthel Index. The following ratings will also be added: Compiling the Morse scale, Pharmacological history, CIRS (Cumulative Illness Rating Scale)

Participants have been instructed to get up from a chair, walk up to a sign marked on the floor 3 meter ahead on the chair, turn around in their own circles, walk up to the chair and sit down. The time of performance is measured in seconds and lower values indicate better balance control and lower fall risk.

This test evaluates the dynamic balance of patients. The test involves the execution of a pre-established series of steps (forward, lateral, backward) within four squares. The time taken to complete one clockwise and one counterclockwise revolution is taken as a reference parameter.

The 15-second threshold helps us assess the risk of falling in the population being studied.

Times longer than 15 seconds are associated with a higher risk of falling. The young population is around 6-7 seconds.

The index, has it to establish the patient's degree of independence. It is made up of 10 items that include the municipalities daily activities (ADL Activities of Daily Living). Each item is assigned a score, the sum (maximum 100) indicates the degree of autonomy of the patient in carrying out the activities of daily life, the higher the score, the greater the autonomy of the subject.

It is a standardized tool used in the medical field to measure the patient's health as objectively as possible. The tool is clinical in nature and requires the physician to evaluate and measure the clinical and functional severity of 14 categories of disease. For each of these pathologies a severity value must be defined, based on the clinical history, the physical examination and the symptoms declared by the patient. The scale has a cumulative score, which can range from 0 to 56. According to its developers, the maximum score is not compatible with the patient's life.