Gait rehabilitation with treadmill has been reported to be useful in patients with Parkinson's disease. In the last years, interest in robotic devices for gait training has grew up for patients with different neurological disorders, since they minimize demands on physical therapists and may provide a more reliable and constant treatment.

The aim of this study is to evaluate if robotic gait training with Lokomat® can improve walking more than conventional gait training with treadmill in patients affected by Parkinson's disease.

Inclusion Criteria:

• patients affected by PD with a disease stage < III according to Hoehn and Yahr's classification and age < 75 years;
• absence of motor fluctuations;
• able to ambulate independently;
• no treadmill training for at least 6 months before the study.

Exclusion Criteria:

• current levodopa therapy started more than 6 months before enrollment;
• medical or neurological pathology that contributed significantly to gait dysfunction, as musculoskeletal disease, severe osteoarthritis, peripheral neuropathy, previous lower limb joint replacement, cardiovascular disease (recent myocardial infarct, from less than 4 weeks or uncontrolled hypertension, with blood pressure > 180/110 at rest);
• hearth failure (NYHA >=3);
• orthostatic hypotension;
• body weight over 100 kg;
• respiratory disease;
• dementia;
• depression;
• uncorrected visual disturbances.
• patients that have undergone deep brain stimulation.