ARC-IM Therapy To Support and Promote Recovery of Ambulatory Functions in People With Subacute and Chronic Spinal Cord Injury

Assess the preliminary safety of ARC-IM Therapy in participants with subacute and chronic SCI.

The ASIA ISNCSCI is a clinical examination used to assess the motor and sensory impairment and severity of a spinal cord injury.

The 10MWT assesses walking speed in meters per second over a short duration. It measures the time taken by the subjects to walk 10 meters. The test will be performed twice, at self-selected and at maximum velocity. Participants can use their habitual assistive device. The test will be conducted both with and without stimulation.

The 6MWT assesses endurance by measuring the distance in meters a participant walks in 6 minutes. Participants can use their habitual assistive device and can take as many standing breaks as they need, but the timer will not be paused. This test will be conducted both with and without stimulation.

The TUG evaluates functional mobility. Participants begin seated, then stand up, walk 3 meters, turn around, walk back, and sit down. The time taken to complete the sequence is recorded. Assistive devices may be used if necessary. The test will be conducted both with and without stimulation.

The WISCI II assesses the extent and nature of assistance a person with SCI requires to walk, using an ordinal scale of 20 levels, ranging from the most severe impairment (level 0) to the least severe impairment (level 20). The level is determined based on the use of assistive devices, braces, and the physical assistance of one or more persons. The test will be conducted both with and without stimulation.

The SCI-FAI assesses functional walking ability. It is an observational gait assessment that includes 3 key domains of walking function, where 0 is the minimum and worst outcome: gait parameters (maximum score of 20 points), assistive device (each limb scored individually - maximum score of 14 points), and temporal distance (maximum score of 5 points). The test will be conducted both with and without stimulation.

Multifactorial gait analysis that relies on high-precision recordings of whole-body kinematics and kinetics of each gait cycle will be performed. The test will be conducted both with and without stimulation.

The GAS is used to evaluate the participant's progress toward one or more personalized goal(s), which are individually defined by the participant. Each goal is scored on a standardized scale ranging from -2 (outcome is much less than expected) to +2 (outcome is much more than expected), allowing to assess to which extent the goal is met. The form will be completed for both with and without stimulation condition.

The BBS assesses static and dynamic balance through 14 tasks, such as standing, reaching, and turning. Each item is scored on a 5-point scale (0-4) with higher scores meaning better ability to perform the assessed activity. Item scores are then summed, with a maximum score of 56. The use of assistive devices is not allowed. The test will be conducted both with and without stimulation.

Independent use of the ARC-IM Lumbar System by study participants will be evaluated through analysis of the ARC-IM stimulation usage log.

Integration of ARC-IM Therapy within the standard-of-care for subacute SCI will be evaluated by quantifying its use within standard clinical mobility rehabilitation procedures. This will be achieved by extracting and comparing data of the Stimulation Usage Log and Participant's Calendar Log.

Effect of ARC-IM Therapy on the modulation of the spinal cord will be evaluated through electrophysiological assessments that will quantify the muscle responses to EES and adaptation of these responses over time.

Effect of ARC-IM Therapy on trunk stability will be evaluated using the FIST-SCI. The FIST-SCI assesses sitting balance. It evaluates sensory, motor, proactive, reactive, and steady state balance factors based on 14 items, each scored on an ordinal scale from 0 to 4, where 0 means complete assistance is needed to perform the task successfully, and 4 means can complete the task independently and successfully. The test will be conducted both with and without stimulation.

Effect of ARC-IM Therapy on muscle tone will be evaluated using the MAS. The MAS assesses spasticity in a participant's upper and lower limb, by rating the resistance of a muscle to passive movement at a single joint on a 6-point nominal scale, where 0 means no increase in tone, and 5 means affected parts are rigid in flexion or extension. The clinical examination will be performed both with and without stimulation on different days at similar times. Antispastic medication and time points of test/medication intake will be documented.

Effect of ARC-IM Therapy on muscle tone will be evaluated using the SCATS. The SCATS assesses 3 types of spastic motor behaviors in SCI patients - clonus, flexor spasms, and extensor spasms. The clinical examination will be performed both with and without stimulation. Antispastic medication and start time of the test will be documented for inter-test reliability.

Effect of ARC-IM Therapy on quality of life will be evaluated with the SCI-QoL SF. The SCI-QoL SF is a PROM for individuals with SCI. It is divided into 4 domains (emotional health, physical-medical health, social participation, physical functioning) with a selection of 22 subdomains. Each subdomain has several items. The participant rates each item with a number between 1 and 5 according to the extent to which the statement it contains applies to them. Each subdomain is scored separately. The higher the score, the higher the participant's perceived quality of life.

Effect of ARC-IM Therapy on quality of life for chronic SCI participants will be evaluated with the EQ-5D-5L questionnaire. The EQ-5D-5L is a PROM that describes the patient's health state for five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems, slight problems, moderate problems, severe problems and extreme problems.

Effect of ARC-IM Therapy on the subjective change of overall status will be evaluated with the PGI-C. The PGI-C is a single-item questionnaire to measure the change of clinical status, injury severity, or injury improvement, and evaluate the response of a condition to the given therapy. It is a 7-point scale where the participant rates his/her improvement or deterioration on a scale from "1 = very much improved" to "7 = very much worse".

Effect of ARC-IM Therapy on functional independence in daily living will be evaluated with the SCIM III score. The SCIM III is a disability score that addresses functional ability in daily living in people with SCI. Three specific areas are assessed: self-care (0-20 points), respiration and sphincter management (0-40 points), and mobility (0-40 points). The form will be filled out as per stimulation use of the participant in his/her daily life activities for with or without stimulation condition. Total score ranges between 0 and 100 points, with higher scores reflecting greater independence.

The SUS is a standardized post-usability test questionnaire comprised of 10 Likert-scale questions used to evaluate the usability of the investigational system. To collect the SUS score, participants rate how strongly they agree or disagree with statements on a 1 (strongly disagree) to 5 (strongly agree) scale.

Effect of ARC-IM Therapy on pain will be evaluated with the EPAF. The EPAF is used for classification of existing pain problems in people with SCI. The clinical assessment form consists of 12 items and follows the international guidelines and recommendations for the clinical documentation and assessment of pain in SCI. One overall form will be completed summarizing with and without stimulation condition.

Effect of ARC-IM Therapy on bone mineral density will be evaluated using DEXA. Participants will lie in a supine position during the scan, following standardized protocols.

Effect of ARC-IM Therapy on muscle mass will be evaluated using QCT-Scan. The QCT-Scan is used to assess muscle mass by providing high-resolution cross-sectional images of the thigh and the trunk. It allows for precise measurement of muscle volume and composition. Participants will undergo the scan in a supine position, and standardized protocols will be used to ensure consistency across time points.

The Additional User Feedback is a form designed to collect qualitative feedback from participants regarding their interaction with the ARCIM Lumbar System. It includes rating items to evaluate satisfaction (from "not satisfied at all" to "very satisfied") and open-ended questions addressing ease of use, satisfaction with system components such as battery life, charging time, connection stability, and overall comfort during use.