Functional Electrical Stimulation Plus High Intensity Interval Training at Home

Combining Functional Electrical Stimulation With High Intensity Interval Training at Home

People living with SCI may experience loss of sensation, movement and regular body function. One way to address these impairments is activity-based therapy (ABT), which includes movement-based activities that promote the muscle-brain connection below the level of injury. A technology often used during ABT is functional electrical stimulation (FES), which is an electrical stimulus applied to nerves or paralyzed muscles through sticky gel pads placed on the skin. The purpose of this multi-method pilot study is to look at the safety, interest in and acceptance of an at-home, virtual training program that combines FES with high intensity interval training (HIIT). Up to 24 individuals with SCI will be enrolled in the study. The study activities will span over 34 weeks, from pre-training tests to the 12-week follow-up tests.

Study Overview

• Status: Not yet recruiting
• Conditions: Spinal Cord Injuries (SCI)
• Intervention / Treatment: Other: FES+HIIT@Home

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Kristin E Musselman, PhD; Phone Number: 6190 416-597-3422; Email: kristin.musselman@utoronto.ca
• Study Contact Backup: Name: Katherine Chan, MSc; Phone Number: 6199 416-597-3422; Email: katherine.chan@uhn.ca

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M4G 3V9
      • KITE Research Institute, Toronto Rehabilitation Institute-University Health Network
      • Contact: Kristin E Musselman, PhD; Phone Number: 6190 416-597-3422; Email: kristin.musselman@utoronto.ca
      • Contact: Katherine Chan, MSc; Phone Number: 6199 416-597-3422; Email: katherine.chan@uhn.ca
      • Principal Investigator: Kristin E Musselman, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Be an adult (i.e., ≥18 years old) with a SCI at T12 or above as individuals with a lower motor neuron condition are considered poor candidates for FES.
2. Have a SCI rated as American Spinal Injury Association Impairment Scale A, B, C or D. If no recent (i.e., in past six months) AIS rating is available in the medical record, the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) exam (Rupp et al. 2021) will be completed by the research team.
3. Be >1 year post-injury, in the case of traumatic SCI, or >1 year post-onset of neurological symptoms, in the case of a non-progressive, non-traumatic cause of SCI.
4. Be able to attend 8 assessment sessions and three education sessions at the Lyndhurst Centre or Rumsey Cardiac Rehab, as well as 36 FES+HIIT@Home sessions and one education session on Microsoft Teams.
5. Be ambulatory or use a manual wheelchair.
6. Be able to don/doff electrodes independently or with support from a family member or other caregiver.
7. Have physician clearance to participate in high intensity interval training (i.e., no contraindications to HIIT).
8. Have an emergency contact who can be reached by the research team during FES+HIIT@Home sessions.
9. Able to understand spoken English.

Exclusion Criteria:

1. Presents with contraindications to FES (i.e. implanted electronic device, radiation in past six months, active deep vein thrombosis, pregnancy) (Houghton et al. 2010).
2. Presents with cognitive deficits that would prevent independent use of an FES device.
3. Has irritated and/or damaged skin in areas where the electrodes will be applied.
4. Has a cardiovascular morbidity that would limit exercise tolerance, as identified through pre-intervention cardiorespiratory fitness testing (e.g., complex arrhythmias).
5. Participant receives a Botox injection or begins a new therapy or exercise program during the first 20 weeks of the study (i.e., prior to the post-intervention assessments).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: FES+HIIT@Home; Functional electrical stimulation combined with high intensity interval training at home

Other: FES+HIIT@Home; The FES+HIIT@Home intervention will be 16 weeks in duration. During the first four weeks of the FES+HIIT@Home intervention (i.e., weeks 3-6), participants and caregivers who will be assisting will receive education and hands-on training with FES and HIIT exercises. Each participant will receive a two-channel FES device to keep (i.e., Chattanooga® Continuum). During weeks 7-18, participants will complete 36 online, group-based FES+HIIT@Home sessions (i.e., three 1-hour sessions/week for 12 weeks) that are led by trainers over Microsoft Teams. Sessions will include warm-up exercises (10 minutes), three task-specific exercises (15 minutes/exercise) and cool-down exercises (5 minutes). Each task-specific exercise will be performed in 30-second "all out" bouts with a 1.5-minute rest after each bout.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Enrollment rates	Number of participants screened per month (plus reasons for exclusion) and the number of participants enrolled per month	During enrollment
Adherence	Session attendance (plus reasons for absences) and assessment attendance (plus reasons for omissions)	From enrollment until the end of the study at 34 weeks
Feasibility of FES+HIIT@Home	Number of sessions in which each participant achieves the targeted "all out" RPE (and HR for those with lower thoracic SCI)	During the FES+HIIT@Home intervention
Attrition	Number of participants who drop out of the study and the reasons for drop out	From enrollment until the end of the study at 34 weeks
Safety of FES+HIIT@Home	Number of minor and serious adverse events	From enrollment until the end of the study at 34 weeks
Function for participants unable to stand	Function will be assessed with the Function in Sitting Test (FIST-SCI) for participants unable to stand. The FIST-SCI assesses postural control during functional sitting activities. Items are rated on the amount of assistance required to accomplish each task on a 5-point scale of 0 (complete assistance - patient cannot perform the task at all) to 4 (independent - patient completely autonomous in performing the task). Scores can be summed for a total score ranging from 0 to 56.	From enrollment to the end of the 12-week follow-up at 34 weeks
Function for participants able to stand	Function will be assessed with the mini-Balance Evaluation Systems Test (mini-BESTest) for participants who are able to stand. The mini-BESTest assesses a variety of functional activities in standing and walking. The Mini BESTest is scored on a 3-level ordinal scale (0 to 2). Scores can be summed for a total score between 0 and 28.	From enrollment until the end of the study at 34 weeks
Muscle Strength	Isometric strength of the trunk, upper limb and lower limb muscles will be evaluated with manual muscle testing (MMT) and/or hand-held dynamometry. Testing positions will be standardized, following guidelines of the ISNCSCI, as appropriate, and strength scored on a 0 to 5 scale. Muscles with a MMT score of ≥4 will also be assessed with hand-held dynamometry, which is a valid assessment method that has greater sensitivity to detect changes in the strength of stronger muscles. Three peak force values will be collected per muscle group and the mean value normalized by body weight.	From enrollment until the end of the study at 34 weeks
Penn Spasm Frequency Scale	The Penn Spasm Frequency Scale is a valid and reliable self-report measure that evaluates an individual's perception of spasticity frequency (on a 5-point scale from 0 (no spasms) to 4 (spontaneous spasms occurring ≥10 times/hour)) and severity (on a 3-point scale from 1 (mild) to 3 (severe)). A spasm severity rating will not be provided if spasm frequency is 0.	From enrollment until the end of the study at 34 weeks
Spinal Cord Assessment Tool for Spastic Reflexes	The Spinal Cord Assessment Tool for Spastic Reflexes is a short clinical exam of three spastic motor behaviors in the lower limb of individuals with SCI: clonus, flexor spasms and extensor spasms. The reactions observed for each motor behavior will be rated on a 4-point ordinal scale and summed for a total score (/9).	From enrollment until the end of the study at 34 weeks
Exercise Self-efficacy Scale	Exercise self-efficacy will be assessed with the SCI Exercise Self-efficacy Scale, which assesses confidence in performing exercise. Participants will rate their confidence, on a scale from 1 (not always true) to 4 (always true), for ten statements related to carrying out regular exercise and physical activity. Reponses are summed for a total score (/40).	From enrollment until the end of the study at 34 weeks
Cardiorespiratory fitness	VO2peak (mL/kg/min), will be evaluated with a maximal graded exercise test. Breath-by-breath gas samples will be collected and averaged over 20 seconds via a calibrated metabolic cart to determine V̇O2peak.	From enrollment until the end of the study at 34 weeks
Arterial stiffness	Pulse wave velocity (PWV, m/s) will be obtained between the common carotid and common femoral arteries (cfPWV). cfPWV (m/sec) will be calculated using the equation: (0.8 × D)÷Δt, where D is the distance between measurement sites and Δt is the pulse transit time.	From enrollment until the end of the study at 34 weeks
Description of the contexts that impact outcomes of FES+HIIT@Home	To describe the contexts (e.g., virtual setting, group sessions) that impact outcomes from the perspectives of people with SCI	After 24 sessions (or 8 weeks) of the FES+HIIT@Home intervention and at the 12-week follow-up at 34 weeks
Description of the mechanisms that impact outcomes of FES+HIIT@Home	To describe the mechanisms (e.g., FES, HIIT, education) that impact outcomes from the perspectives of people with SCI	After 24 sessions (or 8 weeks) of the FES+HIIT@Home intervention and at the 12-week follow-up at 34 weeks

Collaborators and Investigators

• Sponsor: University Health Network, Toronto
• Investigators: Principal Investigator: Kristin E Musselman, PhD, University Health Network, Toronto

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): July 1, 2028
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: August 11, 2026
• First Submitted That Met QC Criteria: August 14, 2026
• First Posted (Actual): August 19, 2026

Study Record Updates

• Last Update Posted (Actual): August 19, 2026
• Last Update Submitted That Met QC Criteria: August 14, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: functional electrical stimulation; high intensity interval training; home-based rehabilitation
• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Trauma, Nervous System; Spinal Cord Diseases; Spinal Cord Injuries
• Other Study ID Numbers: 26-5324

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The de-identified, quantitative datasets will be shared through the Open Data Commons for Spinal Cord Injury (odc-sci.org) and supplementary files will be made available in the publications.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No