recoveriX PRO system is a Brain-Computer Interface (BCI) device that combines Motor Imagination (MI), with Functional Electrical Stimulation (FES) and Virtual Reality (VR) as feedback devices. The user wears an electroencephalography (EEG) cap that registers the neural activity during the mental practice. This system allows the user to control the feedback devices (FES +VR) with the MI.

The goal of this clinical trial is to know the safety and clinical effectiveness of recoveriX-based treatment for improving gait functions in stroke patients. Researchers will compare the functional results obtained by recoveriX system, to the standard treatment based in FES + VR + MI without monitoring the EEG activity.

The questions to answer are:

1. Will stroke patients who undergo recoveriX therapy significantly improve their gait ability?
2. Is the functional improvement (gait speed) achieved with the BCI treatment superior to the standard MI+FES+VR treatment?
3. Is the recoveriX-based therapy as safe as the standard treatment?

Participants will have to perform a complete assessment to evaluate their functionality before and after the intervention (motor skills, walking ability, impact of the disease in daily living activities).

Patients in the BCI group will receive 25 sessions (3 sessions per week) of BCI training with FES and VR feedback (24 sessions in total).

Patients in the control group will receive 25 sessions (3 sessions per week) of FES + VR therapy. Patients in the control group will receive the same instructions as the experimental but will not wear the EEG cap.

Inclusion Criteria:

• 6-months or more post stroke
• With a restriction of the lower extremities preventing the persons from activities of daily life
• Participants must be German speaking.
• Demonstrate intact cognition to provide informed consent and follow instructions.
• Be able to perform TUG and 10MWT (3 times).

Exclusion Criteria:

• Debilitating conditions or vision impairment that would impede full participation in the study.
• Other neurological conditions affecting the motor system or the compliance to the therapy (for example Polyneuropathy or Musculoskeletal Diseases).
• Uncontrolled epilepsy or seizures
• Significant circulatory disturbances of the stimulated extremities
• Inability to independently maintain the seated position (without assistance) for about 60 minutes.
• Pregnant
• Active or passive implanted medical devices such as pacemakers which do not allow the use of FES.
• Implanted metallic fragments in the upper and lower extremities which can limit the use of FES.
• Under the influence of anesthesia or similar medication.
• With fractures or lesions in the extremity to be stimulated.
• Inadequate control of a BCI system.
• Sensory disorders which can significantly affect the patient's ability to feel pain and to react to unsuitable proprioceptive stimuli.
• Botulinum toxin treatment of his/her paretic lower limb during this study