Postural instability is a particularly incapacitating disorder, where loss of motor independence by Parkinson´s Disease (PD) patients marks a significant stage of disease onset. Evidence suggests that deficits in automatic motor control, sensory integration and attention are associated with lack of balance in PD. Physiotherapy, together with medication, plays an important role in the treatment of this state, although no consensus has been reached on the best treatment modality. The aim of this randomized controlled trial protocol is to evaluate the effects of balance training with rhythmical (BRT), which is a motor program to improve balance associated with rhythmical auditory cues (RACs)

A total of 150 PD patients at H&Y stages II-III and asymptomatic for depression and dementia are enrolled in a single-blind randomized study. Randomization is achieved via a computer-generated random-sequence table. All patients should also present a fall history.They will be assigned into one of three groups, and their balance and gait will be assessed before and after 10 training sessions, and after 4 and 30 weeks subsequent to the end of the training. Balance will be assess by Mini BESTest (MBESTest), BERG Test (BBS) and Postural Stress Test (PST). Gait will be evaluate by the Timed Up and Go test (TUG). Independence in Activities of Daily Living (ADLs) will be assess through interviews; and UPDRS, through motor performance. The BRT group received a motor program to improve balance associated with RACs, the MT group performed motor training with the same aims as those in the BRT group but without RACs, and the control group (CG) was trained only in orientations. The exercise program specific to balance is of 5 weeks' duration with two sessions per week, 45 minutes each, and consists of general physiotherapy exercises. Each session is divided into five warm-up minutes-30 minutes for the main part and 10 minutes for the cool down. The training progresses and intensifies each week depending on the individual's performance. The subjects should be able to execute 10 repetitions of the exercise sequences correctly to progress to the next movement.

The training progressed and increased in intensity on each week. On the first week, before the training, each exercise was explained and demonstrated by the physiotherapist, who demanded special attention on the most difficult aspects of movement execution. The subjects performed 05 repetitions (5 RM) of each exercise.

On the first phase the patients may present some mistakes and might need specific information to correct the movement that is on execution. The exercises will be repeat in the next sessions in order to consolidate learning. The subjects must have been capable of associating the corrections to the exercises that will proposs on the first week. In each group repetition, for both groups, the physiotherapist will use a verbal command before each movement change, anticipating it and requesting attention to the most difficult ones. Only the GBRT will be oriented to focus on the rhythmical auditory cues. On the second week, the subjects will perform a series of 10 repetitions (10 RM) and on the third week, 2 series of 10 repetitions (20RM). On the fourth week, subjects must have been able to execute 20RM of the exercise sequences with an increase in speed.

Inclusion Criteria:

• All of the subjects will be diagnosed by neurologists from the Movement Disorders Ambulatory Clinic of the University of São Paulo Faculty of Medicine Clinics Hospital, according to the UK Brain Bank criteria [36] and should be at H&Y classification stage II or III, with a Mini Mental Status Examination (MMSE) [37] score of above 24.
• All patients should also present fall history.
• They should have the capacity to ambulate independently indoors without aid.

Exclusion Criteria:

• These are the presence of neurological, orthopedic or cardiopulmonary problems, an unstable medication regime, and an inability to understand or adhere to the protocol because of, for example, cognitive, auditory or visual problems.
• Patients receiving physical therapy training will also be excluded from the training.