What this trial measures

• Safety: occurrence of adverse eventsLast week of training (Month 4)

  Non-serious adverse events may include transient muscle soreness, fatigue, mild dizziness, temporary loss of balance corrected by the helper buddy, or minor joint discomfort during home exercise. These events do not require medical intervention and are reported during weekly check ins or directly to study staff. Serious adverse events include any event resulting in injury requiring medical care, hospitalization, life-threatening symptoms, severe cardiovascular responses (chest pain, uncontrolled shortness of breath, hypertensive crisis), oxygen desaturation below safety thresholds, or falls causing significant injury. The helper buddy is instructed to stop activity immediately, call emergency services when necessary, and notify the research team. All adverse events are monitored throughout screening, assessments, and training sessions, and are reviewed by the PI with prompt IRB reporting as required.

• AdherenceEnd of training (Month 4)

  Adherence will be monitored by tracking completion of all scheduled home training sessions, weekly Zoom check ins, and timely completion of progression evaluations and questionnaires. Participants are expected to complete 2 sessions per week for 4 months, and adherence will be defined as completing at least 75 percent of planned sessions. Attendance logs, helper buddy confirmation, and participant self reports are reviewed weekly by study staff to document adherence and address barriers to participation.

• Change in Physical Function measured by Short Physical Performance BatteryBaseline, 1 week post-training

  The Short Physical Performance Battery (SPPB) is a validated measure of lower extremity physical function that includes three components: standing balance, gait speed, and repeated chair stands. Balance is assessed using side by side, semi tandem, and tandem stances; gait speed is measured over a short walking distance; and strength/mobility is evaluated using five repeated chair rises. Scores from each component are combined into a 0-12 total score, with higher scores indicating better physical function. For this study, the SPPB is administered remotely over Zoom with camera positioning and helper buddy support to ensure safety during all standing and mobility tasks.

• Change in Walking Function: Dynamic Gait Index (DGI)Baseline, 1 week post-training

  The Dynamic Gait Index (DGI) is a clinical measure of functional gait performance that assesses an individual's ability to adapt walking to varying task demands. The test includes eight walking tasks such as changing gait speed, head turns, pivot turns, stepping over obstacles, and stair climbing. Each task is scored on a 0-3 scale, with a maximum total score of 24; higher scores indicate better dynamic gait stability. In this study, the DGI is administered remotely with helper buddy supervision to ensure safety during all gait tasks.

• Change in Walking endurance: Timed 25-Foot WalkBaseline, 1 week post-training

  The Timed 25-Foot Walk is a standardized measure of gait speed and lower extremity mobility in persons with neurological conditions. Participants are instructed to walk 25 feet as quickly and safely as possible, and the time to complete the distance is recorded in seconds. Faster times indicate better ambulatory function. In this study, the Timed-25 Foot Walk is administered remotely over Zoom with appropriate camera positioning and helper buddy supervision to ensure safety during the walking task.

• Change in information processing speedBaseline, 1 week post-training

  The Symbol Digit Modalities Test evaluates information processing speed, attention, and visual scanning. Participants are shown a key that pairs simple symbols with numbers and are asked to verbally report the number corresponding to each symbol presented on the screen as quickly and accurately as possible within a fixed time period. The test takes approximately 5 minutes to complete. The Symbol Digits Modalities score is calculated as the total number of correct symbol-number pairings completed within the time limit, with scores typically ranging from 0 to approximately 110. Higher scores indicate faster processing speed and better performance, while lower scores reflect greater difficulty with information processing.

• Change in verbal learning and memoryBaseline, 1 week post-training

  The California Verbal Learning Test-II assesses verbal learning and memory. Participants hear a list of words read aloud by the examiner and are asked to recall as many words as possible immediately after each presentation. This procedure is repeated across five learning trials using the same word list. The task takes approximately 7-10 minutes. The score used for BICAMS is the total number of words correctly recalled across the five learning trials, with possible scores ranging from 0 to 80. Higher scores indicate better verbal learning and memory, while lower scores indicate greater difficulty with learning and recalling verbal information.

• Change in visuospatial learning and memoryBaseline, 1 week post-training

  The Brief Visuospatial Memory Test-Revised evaluates visuospatial learning and memory. Participants are briefly shown a display of simple geometric figures arranged in a specific pattern. After the figures are removed, participants are asked to reproduce the figures and their locations from memory. This process is repeated across three learning trials and takes approximately 5 minutes. The Brief Visuospatial Memory Test-Revised score used for Brief International Cognitive Assessment for Multiple Sclerosis is the total recall score across the three trials, with possible scores ranging from 0 to 36. Higher scores indicate better visuospatial learning and memory, while lower scores reflect greater visuospatial memory impairment.

• Change in Dual-task balance costBaseline, 1 week post-training

  Dual-Task Balance Cost (Limits of Stability + Letter-Number Sequencing) Dual-task balance cost is assessed by combining the Limits of Stability test with a concurrent Letter-Number Sequencing task. Participants perform controlled reaching movements in multiple directions while simultaneously generating an alternating number-letter sequence. Balance performance (reach distance and control) and cognitive accuracy are recorded under both single-task and dual-task conditions. Dual-task cost is calculated as the relative change in balance performance when the cognitive task is added. This assessment is conducted remotely over Zoom with helper buddy supervision for safety.

• Change in Community Mobility: University of Alabama Birmingham (UAB) QuestionnaireBaseline, 1 week post-training

  The Life-Space Questionnaire assesses real-world community mobility by capturing how far and how often a person moves through different life-space levels, ranging from within the home to travel outside the local community. Scores reflect the frequency, independence, and distance of mobility over the past four weeks, with higher scores indicating greater community mobility. In this study, the questionnaire is completed remotely via REDCap or Zoom based on participant preference.

• Change in Community Mobility: AccelerometerBaseline, 1 week post-training

  Community mobility is objectively measured using a wearable ActiGraph accelerometer worn for 7 consecutive days for at least 12 hours per day. The device captures step counts, activity levels, and movement patterns that reflect real-world mobility outside the laboratory or home. Data are downloaded and analyzed to quantify overall mobility and time spent in different activity intensities. Participants receive the device by mail and return it using a prepaid shipping label.

• Change in Quality of Life: Multiple Sclerosis Impact Scale (MSIS-29)Baseline, 1 week post-training

  Quality of life is assessed using the Multiple Sclerosis Impact Scale (MSIS-29), a validated self-report questionnaire measuring the physical (20 items) and psychological (9 items) impact of MS on daily functioning. Scores reflect the extent to which MS affects mobility, activities, mood, and overall well-being, with higher scores indicating greater impact. The MSIS-29 is completed remotely via REDCap or during a Zoom session based on participant preference.

• Change in Balance Confidence: Activities-Specific Balance Confidence (ABC)Baseline, 1 week post-training

  Balance confidence is measured using the Activities-Specific Balance Confidence (ABC) Scale, a validated 16-item questionnaire assessing an individual's confidence in performing common daily activities without losing balance. Participants rate their confidence from 0 to 100 percent for each activity, with higher scores indicating greater balance self-efficacy. The ABC Scale is completed remotely via REDCap or during a Zoom session according to participant preference.