Functional Electrical Stimulation Cycling for Managing Mobility Disability in People With Multiple Sclerosis

Walking speed will be assessed using the timed 25-foot walk (T25FW) test. Participants will walk as quickly and safely as possible across a 25-foot distance (2 trials; average reported in m/s).

Walking endurance will be assessed using the 2-minute walk (2MW) test. Participants will walk as fast and as far as possible in an accessible hallway (1 trial, distance traveled recorded in meters).

Agility will be assessed using the Timed Up-and-Go (TUG) test. Participants will rise from a chair, walk 3 meters, turn around, walk back to the chair and return to a seated position (2 trials, time recorded in seconds for both trials)

Patient-rated impact of MS on walking will be captured using the Multiple Sclerosis Walking Scale-12 (MSWS-12). The MSWS-12 is a 12-item questionnaire that assesses the impact of MS on daily functioning with scores ranging from 0 to 100, where higher scores indicate greater walking impairment.

The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) battery involves three cognitive tasks: the oral version of the Symbol Digit Modalities Test (SDMT), the California Verbal Learning Test II (CVLT-II), and the revised Brief Visualspatial Memory Test (BVMT-R). The SDMT is a timed thinking task that involves associating numbers with symbols. Participants will be asked to provide as many correct numbers as possible in 90 seconds. The CVLT-II is a test of verbal memory and involves recalling a list of words read aloud by an examiner. The participant will be read a list of 16 words and asked to recall as many words as possible. The BVMT is a test of visual memory which involves recalling and manually drawing a series of 6 abstract designs as accurately as possible. The SDMT is performed once, while there are five trials of the CVLT-II and three trials of the BVMT in the BICAMS battery. Higher scores on all three tests indicate better cognitive function.

The Paced Auditory Serial Addition Test (PASAT) involves single numerical digits being presented to a participant every 3 seconds. The participant must add each new digit to the one immediately preceding it. There are 61 numbers presented in total and the total number of correct responses is recorded. Higher scores indicate better cognitive function.

Fatigue impact will be assessed using the Modified Fatigue Impact Scale (MFIS). The MFIS is a 21-item questionnaire with three subscales (physical, cognitive, and psychosocial), that assess the impact of fatigue on daily functioning over the past 4 weeks. Total MFIS scores are calculated by summing responses for all 21 items, with higher scores indicating greater impact of fatigue. Subscales are calculated based on a subset of items. Scores range from 0-36, 0-40, and 0-8 for physical, cognitive, and psychosocial subscales, respectively, with higher scores indicating greater fatigue.

Fatigue severity will be assessed by the Fatigue Severity Scale (FSS). The FSS is a nine-item questionnaire that assesses perceived fatigue over the past 7 days. Total FSS scores are calculated as a mean of the nine items. Scores on the FSS range from 1-7, where higher scores indicate more severe fatigue.

Pain will be assessed using the McGill Pain Questionnaire (MPQ). The MPQ is a 15-item questionnaire which assesses levels of pain experienced by the participants during a 4-week period. The overall score is calculated by summing responses from each item and can range from 0-45, where higher scores indicate greater severity of pain.

Symptoms of anxiety and depression will be assessed using the 14-item Hospital Anxiety and Depression Scale (HADS). The HADS has two subscales (i.e., anxiety and depression) which each contain 7-items, of which a subset are reserve-scored, and then summed into total scores that range from 0-21. Higher scores on each subscale indicate more frequent symptoms of anxiety and depression.

Health-related quality of life will be assessed using the 29-item Multiple Sclerosis Impact Scale (MSIS-29). The MSIS-29 is a measure of physical and psychological health-related QOL. The physical subscale contains 20 items and the psychological subscale contains nine items. Scores from the physical and psychological subscales are computed to range from 0-100, with higher scores indicating a greater physical and psychological impact of MS on daily activities.

Participation in activities of daily living will be assessed using the abbreviated Late-Life Function and Disability Instrument (LLFDI). The LLDFI contains 15-items within three subscales: basic lower extremity function, advanced lower extremity function, and upper extremity function. Each subscale contains 5-items and scores range from 5-25. A composite score is generated by summing all three subscale scores, and ranges from 15-75, with higher scores indicating fewer functional limitations.