VALSE: Integration of Neuromodulation and Exoskeleton Systems for Mobility in Individuals With Chronic Spinal Cord Injury

The purpose of this clinical study is to evaluate the preliminary safety and feasibility of using the VALSE system, which combines spinal cord stimulation with the TWIICE robotic exoskeleton, to support motor recovery and reduce reliance on laboratory-based equipment during rehabilitation in participants with traumatic spinal cord injury. The TWIICE exoskeleton is integrated through the NR system, a platform developed by EPFL. The goal is to assess the clinical safety and practical application of this combined neuroprosthetic approach in a small number of participants, in order to guide future refinements of the device and protocol, support the development of scalable interventions integrating spinal stimulation with robotic assistance, and inform strategies for delivering rehabilitation in more accessible, real-world environments.

Inclusion Criteria: * Currently enrolled participants who have completed the relevant phase of their parent study at CHUV: BoxSwitch (NCT05942339, after the optimisation phase), Think2Go (NCT06243952, after the rehabilitation phase, or STIMO-BSI (NCT04632290, after the calibration and training phase of the optional extension with system upgrade), * Must have a functional neuromodulation system, * Must be at least 18 years old, * Must be suffering from non-progressive traumatic spinal cord injury, sustained at least 12 months before signing the consent form, * Must weigh less than 100 kg, * Must have a standing height between 160 and 190 cm, * Must be able to grasp and lift bilateral crutches in a seated position, * Must have stable medical, physical and psychological condition as considered by the investigator, * Must be able to understand and interact with the study team in French or English, * Must agree to comply in good faith with all conditions of the study and to attend all scheduled appointments, * Must provide Informed Consent as documented by signature prior to any study-related procedures. Exclusion Criteria: * Must not be diagnosed with severe osteoporosis/penia: Dual Energy X-ray Absorptiometry (DEXA) results indicating a t-score below -3.5 at either the femoral neck or the total proximal femur. Dual Energy X-ray Absorptiometry (DEXA) results indicating a bone mineral density (BMD) \< 0.60 gm/cm2 at any knee region (distal femur, proximal tibia) * Must not have deep vein thrombosis in lower extremities within the past 6 months. * Must not have experienced lower extremity fractures within the last two years. * Must not have current pressure ulcer of the arms, trunk, pelvic area, or lower extremities * Must not present with a flexion contracture \>15° at the hip or knee * Must not have severe concurrent medical conditions that contraindicate moderate to intense exercise (e.g., uncontrolled hypertension, coronary artery disease, congestive heart failure). * Must not have heterotopic ossification that impairs joint mobility * Must not be implanted with a life-supporting medical device (devices implanted in the parent study are not considered life-supporting), * Must not be pregnant, * Must not be the investigator himself, his/her family members, employees, or other dependent persons.