The goal of this interventional study is to assess differences in the metabolic consumption, the cardiorespiratory effort, the cardiac autonomic adaptation, and fatigability during ADL, such as standing from a chair and walking while wearing an electrically powered exoskeleton in different modes of supports in subjects with neurological diseases with moderate to severe walking impairments.

In people with severe gait impairments due to neurological diseases walk recovery is one primary goal, since achieving independent ambulation is a major contributing factor to their quality of life. Beyond walking, other very common Activities of Daily Living (ADL), such as postural transitions (which requires an integrity of the autonomic control mechanisms of blood pressure) and stair climbing (which requires the necessary strength in the lower limbs to lift one's own body weight) should be guaranteed by any rehabilitative intervention. Although physiotherapy treatments have proven effectiveness in improving gait and balance, conventional overground walking training may be very difficult or even impossible for patients with moderate to severe gait problems and limited cardiovascular capacity due to a too high energy demand (exercise intensity) (Calabrò 2022).

Wearable powered exoskeletons could be used to provide overground robotic assisted gait training (RAGT). Indeed, RAGT has shown clinically significant improvements in gait and balance outcomes and could be considered a valid approach to enhance gait function in people with severe gait impairments due to neurological diseases(Bowman 2021).

Little is known about the impact of robotic training on cardiovascular parameters and the metabolic / energy cost of walking with a wearable powered exoskeleton compared to unassisted overground walking in population with neurological diseases. It is possible that exoskeletons allow walking while keeping cardiorespiratory effort under control with a lower metabolic cost.

Moreover, people with severe gait impairments can suffer from disturbed cardiac autonomic control during exercise which affects exercise tolerance and balance during orthostatic challenges, such as the sit-to-stand maneuver. Indeed, to recommend RAGT in people with neurological diseases with moderate to severe gait impairments, the impact of the cardiac autonomic tone on sit-to-standing and walking with an exoskeleton should be investigated.

The use of an assisted as needed exoskeleton in clinical practice with population with moderate-severe neurological disabilities could increase their locomotor function by reducing the impact on metabolic consumption and cardiorespiratory effort compared to conventional overground walking training without an exoskeleton. Moreover, cardiovascular autonomic dysfunction (CAD), if any, should not be worsened by walking with an exoskeleton compared to conventional overground walking training, and should not constitute an impediment in the adaptation of the cardiovascular adaptation (especially of blood pressure) to the postural transitions.

The goal of this interventional study is to assess differences in the metabolic consumption, the cardiorespiratory effort, the cardiac autonomic adaptation, and fatigability during ADL, such as standing from a chair and walking while wearing an electrically powered exoskeleton in different modes of supports in subjects with neurological diseases with moderate to severe walking impairments.

Inclusion Criteria:

• Able to perform 4 minutes of back-and-forth locomotion with assistance or resting periods;
• Height between 160 and 195 cm;
• Weight not exceeding 100 kg;
• Diagnosis of Multiple Sclerosis with moderate to severe disability (5,5 < EDSS < 8,0);
• Diagnosis of stroke or traumatic brain damage (1 ≤ FAC ≤ 3);
• Diagnosis of spinal cord injury with neurological level of injury<T2 (3 ≤ WISCI II ≤ 16) with a Asia Impairment Score B, C or D.
• Able to perform 4 minutes of back-and-forth locomotion with assistance or resting periods;
• Able to use walker;

Exclusion Criteria:

• Impairments in the upper limbs that do not allow the user to hold the crutches/walker.
• Skin injuries in the areas where the exoskeleton is in contact with the user.
• Fractures not solved or bone pathologies in lower limbs in which the use of the exoskeleton could be risky (advanced osteoporosis).
• Psychiatric or cognitive problems that can interfere with the correct use of the device.
• Important muscle/joint retractions in lower limbs (Modified Ashworth Scale > 3).
• Any medical conditions that could interfere with the autonomic cardiovascular control (e.g severe diabetes).
• Use of beta blocker drugs.
• Presence of severe cardiovascular diseases.