Low Load Resistance Training Using Blood Flow Restriction for People With Multiple Sclerosis

The Primary Aim of this research study is to determine the feasibility of 8 weeks of physical therapy strengthening exercises using blood flow restriction (BFR) in people with multiple sclerosis (MS) who have moderate-to-severe walking problems. BFR training involves placing a cuff on the leg being exercised in order to restrict blood flow. The cuff is attached to a specialized device that automatically detects the appropriate amount of pressure to place on the limb. Testing will occur before and after the 8-week treatment period.

Specific Aim 1: Determine the feasibility of BFR by assessing recruitment rate, retention, adherence, satisfaction, and safety.

Hypothesis: Feasibility will be demonstrated by: 1) enrolling 20 participants in 8 months, 2) retaining at least 16 (80%) participants, 3) 80% adherence to intervention, 4) 90% satisfaction with intervention, and 5) no serious adverse events related to the intervention.

Specific Aim 2: Determine changes in knee and hip extension, hip abduction, and ankle plantarflexion muscle strength after the 8-week intervention.

Hypothesis: Following intervention there will be clinically important within-group strength changes that correspond to established minimal detectable change values and which can be characterized as having at least a moderate effect size as defined by Cohen's d.

Exploratory Aim: Explore changes in functional mobility (30-Second Sit-to-Stand, Berg Balance Scale, Timed 25-Foot Walk. 10-day average activity level) and self-report measures (12-Item MS Walking Scale, Modified Fatigue Impact Scale, MS Impact Scale-29, and Patient-Specific Functional Scale) after the 8-week intervention.

Inclusion criteria

• Adults ages 18-70
• Neurologist-confirmed diagnosis of multiple sclerosis
• Expanded Disability Status Scale (EDSS) 6.0 to 7.0

• EDSS 6.0: unilateral assistance (cane or crutch) required to walk at least 100 meters with or without resting
• EDSS 6.5: Bilateral assistance (cane or crutch) required to walk at least 20 meters with or without resting
• EDSS 7.0: unable to walk 5 meters even with aid, essentially restricted to wheelchair; wheels self and transfers alone; up and about in wheelchair some 12 hours a day

Exclusion criteria

• EDSS 7.5 or greater: Restricted to wheelchair for all mobility, unable to walk more than a few steps, even with walking aid
• EDSS 5.5 or less: Able to walk more than 100 meters without walking aid or rest
• Unable to provide consent or follow simple directions
• Prior history of Deep Venous Thrombosis/ Pulmonary Embolism
• History of peripheral vascular disease, thrombophilia or other clotting disorders
• Patient report of easy bruising
• Any comorbid conditions or pain that substantially affects physical function or would interfere with the participant's ability to safely complete rehabilitation (e.g. neurologic, vascular, cardiac problems, orthopedic, or ongoing medical treatments) as determined by a neurologist of physical therapist
• Severe lower extremity spasticity as defined as Modified Ashworth scale > 2
• Currently undergoing supervised resistance training with a physical therapist or other exercise professional
• Use of Blood Flow Restriction currently or in the previous 3 months prior to enrollment
• MS-related exacerbation or changes to their disease-modifying drug therapy in the month prior to enrollment
• Inability to tolerate pressure cuff during baseline assessment