The target of this clinical trial is Freezing of Gait symptom (FoG), and associated falls. The project is aimed to evaluate the effects of an innovative experimental protocol to treat Parkinson (PD) Patients with FoG. This new physiotherapy protocol is based on the recovery of the correct mental representation of the movement, through Action Observation. A method that can facilitate the process of re-learning correct motor strategies, and at the same time avoid the phenomena of external cues dependency. Our version of the Action observation method uses video-clips of gait exercises. In these video-clips the audio part was obtained with the sonification of the kinematics of the body movements. We postulate that action observation, through the activation of the mirror system, is able to reactivate stored motor programs concerning walking ability, which can be used to facilitate recovery of defective motor control and overcome freezing of gait. Moreover, given that patients with PD and FoG may have major shortages of attention resources, a multisensory approach (audio-visual) would help to further reduce the attention load, facilitating learning processes. Therefore half of participants received an experimental protocol with Action Observation plus signification while the other half received a traditional protocol combining visual and auditory cues.