To determine whether the combination of non-invasive spinal cord stimulation together with gait rehabilitation reduces spasticity and facilitates recovery of lower limb motor strength and gait function in patients with incomplete SCI, as well as studying the underlying physiopathological changes following incomplete SCI and its modulation by non-invasive stimulation techniques.

Methodology: This task will involve the clinical and functional assessment of patients completing gait training with and without tSCS as defined in T4.2 to demonstrate the effects of tSCS and define the most favorable parameters. During this task, the assessments that will be completed will be defined by IG and then carried out according to the methodology that is set and agreed upon. Assessments will need to evaluate several factors:

• The American Spinal Cord Injury Association Impairment Scale (ASIA) and the International Standards for Neurological Classification of Spinal Cord Injury (ISNSCI)38 will be used to determine level and severity of SCI and to evaluate sensory and motor deficit.
• For gait outcome measures, 10 meters walking test (10MWT) and Walking Index for SCI (WISCI) II will be assessed.
• For spasticity evaluation, Modified Ashworth modified score (MAS) will be used.
• Neurophysiological studies may be included to study: 1) spinal cord excitability using F and H wave, 2) corticospinal conduction using transcraneal magnetic stimulation for MEP recording, and 3) muscle activity using surface EMG recording of lower limb muscles.

Inclusion Criteria:

• Male or female more than 18 years old;
• With a stable traumatic o nor traumatic incomplete motor cervical or thoracic SCI;
• Time since SCI more than 6 months;
• American Spinal Injury Association Impairment Scale (AIS)-D who could realize gait at least 6 meters with or without technical help;
• Capacity for compression the nature of the study and signed informed consent.

Exclusion Criteria:

• Unstable medical condition (cancer, acute infections, etc.);
• Severe spasticity (≥ 3 score on the Modified Ashworth scale (MAS)),
• Peripheral nerve affectation;
• Ulcers on the electrode applied area;
• Intolerance of tSCS.