Walking difficulties are common symptoms after stroke, significantly reducing quality of life. Walking recovery is therefore one of the main priorities of rehabilitation. Wearable powered exoskeletons have been developed to provide lower limb assistance and enable training for persons with gait impairments by using typical physiological movement patterns. Exoskeleton were originally designed for individuals without any walking capacities, such as subjects with a complete spinal cord injury. Recent systematic reviews suggested that lower limb exoskeletons could be valid tools to restore independent walking in subjects with residual motor function, such as persons post-stroke.The aim of the study was to identify the end-users needs and to develop a user-centered-based control system for the TWIN lower limb exoskeleton to provide an efficient post-stroke rehabilitation of gait. The investigators thus carried out the development and validation through evaluation sessions performed on healthy clinical experts and persons with stroke to evaluate TWIN-Acta usability, acceptability, and barriers of usage. A phase two includes a pilot study of efficacy of using the TWINActa for gait rehabilitation for persons with stroke.

The aim of the study was to identify the end-users needs and to develop a user-centered-based control system for the TWIN lower limb exoskeleton to provide post-stroke rehabilitation. The investigators thus carry out the development and validation of TWIN-Acta: a novel control suite for TWIN, specifically designed for gait rehabilitation of persons post stroke through use of typical physiological movement patterns.

The study will be carried out in two phases. In the first user-centered developmental phase data on usability, acceptability, and limitations to system usage will be collected from clinical experts and persons with stroke through questionnaires and semi-structured interviews.This developmental phase will follow a user-centered approach: it will be based on focus group sessions with clinical and biomechanical experts to define the design specifications for the new control modality of the exoskeleton; consequently evaluation sessions consisting of physical testing of the TWIN-Acta will be carried out by healthy clinical experts and persons with stroke to evaluate TWIN-Acta usability, acceptability, and barriers of usage.

In the second phase of the study a pilot study including 20 sessions of gait rehabilitation of persons at least three month post stroke will be carried out in clinic with the TWIN exoskeleton including the TWIN-Acta control suite.

Outcomes will be verified at baseline and following the intervention through feasibility measures, patient reported outcomes, clinical measures of gait ability and through EMG and 3D gait analysis. The quantitative values will be compared to data of healthy controls walking in the exoskeleton in one session but not receiving any intervention.

Inclusion Criteria:

• Healthy subjects

  • Age 30-75 anni;
  • 50 kg ≤ weight ≤90 kg
  • 150 cm ≤ height ≤ 192 cm
  • Thigh length: 355 ÷ 475 mm;
  • Length of tibia: 405 ÷ 485 mm;
  • Width pelvis: 690 ÷ 990 mm;
  • Shoe number: 36 ÷ 45

• Subjects with stroke

  • Age 30-75 anni;
  • 50 kg ≤ Weight ≤90 kg
  • 150 cm ≤ Height ≤ 192 cm
  • Thigh length: 355 ÷ 475 mm;
  • Length of tibia: 405 ÷ 485 mm;
  • Pelvic width: 690 ÷ 990 mm;
  • Shoe number: 36 ÷ 45;
  • Stroke diagnosis at least 3 months and within 24 months;
  • First unilateral haemorrhagic or ischemic stroke classified as complete or partial infarction of the anterior circulation and infarction of the lacunar circulation (Oxford Stroke Classification: TACS -Total Anterior Circulation Stroke, PACS - Partial Anterior Circulation Stroke, LACS -Lacunar Stroke). These criteria may include hemiplegia, hemianopia, motor and/or sensory deficits, and disturbance/impairment of superior cortical and subcortical function;
  • FAC (Functional Ambulation Category) 1, 2 and 3 (subjects with ambulation dependent on supervisor or continuous or intermittent physical assistance);
  • At least MRC (Medical Research Council) of the triceps surae equal to 1 or greater (required to produce the biofeedback tone or for exoskeleton control).

Exclusion Criteria:

• Healthy subjects

  • Prosthetic implants
  • Musculoskeletal, neurological, cardiovascular and pulmonary disorders that may impair gait;
  • State of pregnancy or breastfeeding.

Exclusion criteria

• Subjects with stroke

  • Mini Mental State Examination < 23/30;
  • Clinical records of visuospatial and ideomotor apraxia, behavioral disorders (e.g. depression, aggression), neglect, major visual impairment and severe osteoporosis;
  • Non stabilized fractures;
  • Cranial injury;
  • Other diseases attributable to cardio-respiratory problemsi;
  • State of pregnancy or breastfeeding;
  • Previous or concurrent neoplastic malignancy;
  • Chronic inflammatory diseases with joint involvement of the lower limbs;
  • Serious spasticity (Ashworth>3);
  • Pelvic fractures and unstable column;
  • Significant limitations of passive ROM of hips and knees;
  • Problems with skin integrity at the interface surfaces with the device or that would prevent sitting.