Anti-Gravity Treadmill Training Improves Walking in a Person with Severe Multiple Sclerosis

Background: Walking dysfunction has a large impact on quality of life for people with multiple sclerosis (PwMS). Gait training has been shown to improve walking function, but PwMS with severe disability require a controlled environment to safely train. Lower body positive pressure (LBPP) treadmills provide the safety, task-specificity, repetition, feedback, body-weight support (BWS) shown to be critical for modifying walking function.

Objectives: To present data demonstrating changes in walking function and muscle-related impairment in one person with severe MS who participated in a pilot study examining the efficacy of LBPP treadmill training.

Methods: One person with MS (Expanded Disability Status Scale Score 7.0) trained for approximately 25-minutes, 2 times/week, for 8-weeks on the AlterG Anti-Gravity Treadmill (AlterG Inc, Fremont, CA). Walking speed (Timed 25-Foot Walk Test (T25FWT)), walking endurance (Two-Minute Walk Test (2MWT)), lower extremity (LE) strength (hand-held dynamometry), balance confidence (Activities Balance Confidence Scale (ABC)), fatigue (Modified Fatigue Impact Scale (MFIS)), and medial gastrocnemius (MG) muscle endurance and oxidative capacity were measured pre and post-intervention. MG muscle endurance was measured using accelerometer-based mechanomyography during 9-minutes of twitch electrical stimulation. MG oxidative capacity was measured using Near-Infrared Spectroscopy, and was was calculated as the rate of recovery of oxygen metabolism (O2Hb) following 15-20 seconds electrical stimulation.

Results: T25FWT decreased by 3.74 feet/sec (25%), 2MWT improved by 65-meters (212%), overall LE strength increased by 6.5lbs (3%), ABC improved by 71.4%, MFIS increased by 10%, muscle endurance increased from 13.5% to 45.09%, and oxidative capacity increased from 0.73 min^-1 to 1.08 min^-1. 

Conclusions: The participant demonstrated improved walking endurance, muscle-specific endurance and oxidative capacity, and balance confidence after training on the LBPP treadmill, suggesting that changes in muscle-specific impairment and confidence may be related to improvements in walking function. She reported a slight increase in fatigue likely due to an increase in participation in exercise and walked slower at the completion of the training, which may be the result of increased attention to walking quality. Further investigation is warranted to understand the efficacy of gait training in the LBPP treadmill environment.