Inclusion Criteria:  Diagnosis os severe Acquired Brain Injury (sABI) Trunk Control Test score greater or equal to 48 Motricity Index Lower Limb score greater or equal to 18 Clinical stability Patient/Caregiver ability to understand ans sing the informed consent  Exclusion Criteria:  Disorder of consciousness (mininally concious state or vegetative state) severe visual impairment (central or peripheral, prior or acquired after the scute event) presence of severe cognitive impairment presence of global aphasia or presence of severe apraxia