The primary purpose of this interventional study is to examine the overall motor learning capacity from exposure to repeated perturbations among ambulatory people with multiple sclerosis (MS). This project will advance our understanding of learning new motor skills from exposure to external perturbations. If it is proven that people with MS can learn motor skills from perturbation training, the findings from this study will pave a theoretical foundation for applying perturbation training as a promising fall prevention intervention for people with MS.

Falls present a significant health risk for people with multiple sclerosis (PwMS). Perturbation training has emerged as a promising strategy to prevent falls. This type of training, which is based on sensorimotor adaptation and motor learning, capitalizes on the central nervous system's (CNS) ability to develop new motor skills. With repeated exposure to large-scale slip or trip perturbations, participants can quickly learn how to better respond to falls. The primary benefits of this training include improved dynamic stability control, both proactively and reactively, by adjusting the body's center of mass (COM) relative to its base of support (BOS).

Sixty-four individuals with relapsing-remitting multiple sclerosis (MS) will be randomly assigned to one of two groups: Group A (training) and Group B (control). Both groups will first participate in an acquisition session. Group A will undergo a training procedure blending slips, trips, and unperturbed walking on a treadmill. In contrast, Group B will walk on the treadmill for the same duration without any perturbations. Immediately following the acquisition session, both groups will experience an unexpected slip and trip while walking over ground (with the order of the slip and trip randomized). Three and six months later, both groups will complete two retention sessions. Each retention session will involve experiencing a treadmill slip and trip (treadmill reslip and retrip) and an overground slip and trip (overground reslip and retrip), with the order randomized. Responses to these perturbations will be measured using the outcomes of fall or non-fall, dynamic stability, leg muscle reaction times, and recovery step length. Additionally, real-life prospective falls and near falls will be monitored for both groups over the six months following the acquisition session.

This project will advance our understanding of learning new motor skills from exposure to external perturbations. If it is proven that people with MS can learn motor skills from perturbation training, the findings from this study will pave a theoretical foundation for applying perturbation training as a promising fall prevention intervention for people with MS.

Inclusion Criteria:

1. Clinically confirmed multiple sclerosis
2. At least 45 years old
3. Able to walk independently at least 25 feet
4. Able to stand independently for at least 30 seconds
5. Patient Determined Disability Steps score between 0 and 4
6. Free from pregnancy
7. Montreal Cognitive Assessment score of 23 or higher

Exclusion Criteria:

1. Previous experience with perturbation training
2. T-score from the dual x-ray absorptiometry (DXA) scan of less than -2.5
3. Coexisting psychiatric disorders or other neurological conditions, severe medical illness, or cardiovascular diseases
4. Participants have had a relapse in the past 8 weeks

Both the participants and outcome assessors will be blinded to each participant's group assignment. However, the researchers who conduct the training will not be blinded.