The objective of this research is to combine the use of inertial systems with virtual reality in pedalling exercises in a pilot study with subjects with ataxia or hemiparesis. In particular, it is intended to evaluate the validity of the system as a physical training tool for pedalling exercises aimed at providing motivational visual stimuli and biofeedback based on pedalling cadence to improve the exercise experience and promote adherence to the subject's treatment.

Primary objectives:

• To study the estimation of pedalling cadence performed by the system/platform in subjects with hemiparesis or ataxia..
• To study the usability, credibility and intrinsic motivation characteristics of the platform

The objective of this research is to evaluate patient adherence to pedalling-based exercise training using visual feedback and virtual reality pedalling cadence analysis. In addition, the usability, credibility and adherence promotion characteristics of the virtual reality platform will be studied.

Study phases:

The procedure will be carried out in the following phases detailed below:

Phase 1: Sample recruitment and participant information. Participants are recruited according to the inclusion and exclusion criteria. The subject is informed about the experimentation in which he/she is going to participate, its duration and the technical characteristics to be used in the study. characteristics to be used in the study. The data to be collected in the form of standardized questionnaires are explained to the subject. Personal data will not be collected. If the subject is suitable for participation, he/she will be asked to sign the corresponding informed consent form. Finally, 3 appointments with the patient will be arranged in accordance with the general schedule of the the general schedule of the experiment.

Phase 2: Familiarization practice with the instrumentation. These will be aimed at acquiring basic skills in the use of the synchronized use of the virtual reality environment synchronized with the pedalling task.

Phase 3: Experimentation and data acquisition.

A.1. Pre-assessment: The participant's motor skills are evaluated based on the application of physical assessment metrics by the physician. The metrics are the "Timed Up-and-Go" (TUG) test and the "6-minute walking" test. Participants with no visual defects, mild cognitive impairment and lower limb motor skills could be selected if they also meet the inclusion/exclusion criteria.

A.2. Validation session of the usability of the Virtual Reality Platform in patients with Ataxia or Hemiparesis. (Approx. 40 minutes) The intervention consists of a pedalling exercise performed on a bicycle or static pedalling station while synchronizing the physical activity with the visual feedback of the virtual reality application. Two pedalling sets of 10 minutes each are performed, with 5 minutes of rest between sets.

A.3. Objective Evaluation: Once the exercise task of the first session is completed, the participant is asked to rate its usability rating: System Usability Rating Scale (SUS), Credibility and Expectancy Questionnaire (CEQ) and Intrinsic Motivation (Intrinsic Motivation). (Intrinsic Motivation Inventory, IMI) of the virtual reality application.

A.4. Subsequent evaluation: The participant's motor skills were evaluated after the three pedalling sessions, based on the pedalling sessions, based on the application of physical assessment metrics carried out by the physician.

Inclusion Criteria:

• Must had been prescribed pedalling exercise as treatment for lower limb rehabilitation caused by stroke, traumatic brain injury, neuro-motor disorders, and neuro-degenerative diseases.
• Must be able to perform a pedalling session with virtual reality technology.

Exclusion Criteria:

• An insufficient cognitive state, in particular, presence of dementia or mild cognitive impairment.
• An unbound bone fracture.
• Severe disorders of vision and/or audition (inability to perceive visual and/or auditory information coming from virtual reality)
• Those whose clinical record ruled out any incompatibility with the use of a virtual reality system.

Twenty participants met these criteria (15 males and 5 females, mean aged=61.10, SD=12.62) diagnosed with (6) ischemic strokes, (1) hemorrhagic stroke, (1) thalamic stroke, (1) internal capsule stroke (3) traumatic brain injury (TBI), (1) Parkinson syndrome, (1) mixed axonal neuropathy with sensory demyelination, (1) progressive multifocal leukoencephalopathy, (1) secondary obstructive hydrocephalus, (1) angioma avernosus hemorrhage, (1) hemiprotuberancial hemorrhage - cavernoma, (1) ataxia and (1) cerebral artery aneurysm.