Researchers are helping Kelly Davis and others with multiple sclerosis walk with the aid of exoskeletons. From left: Marcie Kern, PT; Davis; UTHealth Physical Medicine and Rehabilitation Chairman Gerard Francisco, MD; and TIRR Memorial Hermann CEO Carl Josehart. Photograph courtesy of Dwight Andrews, McGovern Medical School at UTHealth.
Walking with a wearable robotic exoskeleton may enable people with multiple sclerosis (MS) to walk more efficiently by reducing the energy and muscle activity needed to walk, according to research presented at the Association for Academic Physiatrists Annual Meeting held in Sacramento, California, February 16-20.
Researchers from The University of Texas Health Science Center at Houston (UTHealth); TIRR Memorial Hermann, Houston; and Texas Woman’s University recently studied a 33-year-old woman with relapsing-remitting MS who had a score of 6.0 on the Expanded Disability Status Scale (EDSS). The EDSS quantifies disability in patients with MS based on a scale from 0 (no disability) to 10 (death due to MS). The participant received 12 training sessions in exoskeleton-assisted walking and was then asked to perform a series of tests at the end of her training: a Timed Up and Go (TUG) test, a 25-foot walking test at both a self-selected and fast pace, and a six-minute walk test (6MWT). For all tests, the researchers assessed the amount of energy expended as well as the muscle activity in both the upper and lower body. The results of these tests were compared to the results of the same tests completed at the end of the study without the exoskeleton.
During the 6MWT, the participant maintained an approximately 6 percent lower heart rate and required 7.5 percent less oxygen to complete the test in the exoskeleton when compared to walking without it. However, during the 25-foot walking test at a fast speed, the participant’s heart rate was 10 percent higher and oxygen consumption was 3 percent higher when wearing the exoskeleton. Finally, the researchers noticed all muscles in the lower body-with the exception of the semitendinosus, one of three hamstring muscles-showed less activity during the 25-foot walking test at a self-selected speed and the 6MWT when assisted by the exoskeleton. And, similar to energy expended, muscle activity increased during the 25-foot walking test at a fast pace in the exoskeleton. When attempting the TUG test, the participant found it difficult to operate the exoskeleton.
“To promote walking for people with MS, we need to be creative and develop novel strategies. Wearable exoskeletons offer the feasibility of assisted overground walking and may be effective assistance devices to promote efficient walking and better quality of life,” said Shuo-Hsiu “James” Chang, PT, PhD, assistant professor at UTHealth, researcher investigatory at the TIRR Memorial Hermann NeuroRecovery Research Center, and lead investigator in the study. “In our research center, we have another ongoing exoskeleton study that is designed to develop an algorithmic-based evaluation and treatment approach for wearable exoskeleton-assisted rehabilitation that focuses on physiological changes and gait in patients with stroke, spinal cord injuries, and MS. We expect the results will help us to understand better how we can utilize exoskeletons and design effective exoskeleton-assisted rehabilitation programs.”
