INTRODUCTION: Mental practice (MP) and action observation (AO) are characterized as cognitive strategies that contribute to motor planning and learning in diverse populations. Individuals with Parkinson's Disease (PD) are recent targets, since, with disease progression, they need external strategies to aid in motor organization. However, there is still no evidence of the efficacy of MP and AO in the gait of PD. OBJECTIVES: To compare the effects of physical practice preceded by MP and AO on gait performance in individuals with Idiopathic PD (IPD). METHODS: A controlled, randomized, single-blind clinical trial with 66 individuals with IPD, aged between 50 and 75 years, without cognitive deficit and in the moderate phase of the disease will be performed. For the inclusion and characterization of the sample, the following instruments / equipment will be used: (1) Identification form (sociodemographic, clinical and anthropometric aspects); (2) Mini Mental State Examination and Montreal Cognitive Assessment (cognitive level); (3) Hoehn and Yahr Scale (level of physical disability); (4) Revised Movement Imagery Questionnaire (sharpness of the mental image); (5) Qualisys Motion Capture Systems® (gait kinematics); (6) Emotiv Epoc + (electroencephalographic activity); (7) Unified Parkinson's Disease Rating Scale - UPDRS (motor function and activities of daily living); (8) Timed Up and Go Test - TUG Test (mobility); and (9) Parkinson's Disease Questionnaire - PDQ-39 (quality of life).Participants included will be randomly assigned to two groups: experimental (n = 33), who will participate in MP + AO and physical gait practice; and control group (n = 33), who will participate only in the physical practice of gait. Both groups will be submitted to 12 training sessions (3x / week, for 4 weeks) and will be reevaluated 10 minutes, 7 days and 30 days after the last training session with respect to items (4), (5), (6) and (8) of the evaluation. Primary outcomes will be velocity, stride length and range of motion of the hip and the secondary ones will be sharpness of the mental image, electroencephalographic activity and performance in the TUG Test. The normality in the data distribution will be verified through the Shapiro-Wilk test. The "t" test and the Mann-Whitney test will be used to verify the homogeneity of the groups in the baseline. A repeated measures ANOVA will verify the interaction between the groups at the moments observed.

No additional information.

Inclusion Criteria:

• Diagnosis of PD according to the report of a neurologist;
• Age between 50 and 75 years;
• In the moderate stage of the disease (between stages 2 and 3 of the Hoehn and Yahr Scale);
• Use of antiparkinsonian medication;
• Do not present cognitive deficits, according to the Mini Mental State Examination - MMSE. The cutoff point will be defined considering the individual's schooling (Illiterates: 18; With school instruction: 24);
• Ability to imagine motor acts in kinesthetic mode (according to the Revised Movement Imagery Questionnaire - MIQ-R). The cut-off point will be 20 for the kinesthetic modality, indicating that it is at least "a little easy to feel" the kinesthetically imagined movement;
• Have not undergone stereotaxic surgery.

Exclusion Criteria:

• Individuals with other associated neurological diseases;
• Individuals with musculoskeletal disorders, not related to the disease, but that impair gait;
• Individuals with hemodynamic instability before or during training;
• Individuals with uncorrected visual or auditory changes;
• Individuals who do not understand some stage of the training protocol.