A wearable electromyography-controlled functional electrical stimulation system improves balance, gait function, and symmetry in older adults

Article type: Research Article

Authors: Park, Hye-Kang^a | Jung, Joonyoung^b | Lee, Dong-Woo^b | Shin, Hyung Cheol^b | Lee, Hwang-Jae^{c; 1} | Lee, Wan-Hee^{d; *}

Affiliations: [a] Department of Physical Therapy, Graduate School, Sahmyook University, Hwarang-ro, Nowon-gu, Seoul, Korea | [b] Human Enhancement and Assistive Technology Research Section, Artificial Intelligent Research Laboratory, Electronics and Telecommunications Research Institute, Gajeong-ro, Yuseong-gu, Daejeon, Korea | [c] Department of Health Sciences and Technology, Samsung Advanced Institute for Health Science and Technology (SAIHST), Samsung Medical Center, Sungkyunkwan University, Irwon-ro, Gangnam-gu, Seoul, Korea | [d] Department of Physical Therapy, Sahmyook University College of Health Science, Hwarang-ro, Nowon-gu, Seoul, Korea

Correspondence: [*] Corresponding author: Wan-Hee Lee, Department of Physical Therapy, Sahmyook University College of Health Science, 815, Hwarang-ro, Nowon-gu, Seoul, 01795, Korea. Tel.: +82 2 3399 1633; Fax: +82 2 3399 1639; E-mail: [email protected].

Note: [1] Co-corresponding author.

Abstract: BACKGROUND: Wearable technologies have been developed for healthy aging. The technology for electromyography (EMG)-controlled functional electrical stimulation (FES) systems has been developed, but research on how helpful it is in daily life has been insufficient. OBJECTIVE: The purpose of this study was to investigate the effect of the EMG-controlled FES system on muscle morphology, balance, and gait in older adults. METHODS: Twenty-nine older adults were evaluated under two randomly assigned conditions (non-FES and FES assists). Muscle morphology, balance, gait function, and muscle effort during gait were measured using ultrasonography, a physical test, a gait analysis system, and EMG. RESULTS: The EMG-controlled FES system improved gait speed by 11.1% and cadence by 15.6% (P< 0.01). The symmetry ratio of the bilateral gastrocnemius was improved by 9.9% in the stance phase and 11.8% in the swing phase (P< 0.05). The degrees of coactivation of the knee and ankle muscles were reduced by 45.1% and 50.5%, respectively (P< 0.05). Balance improved by 6–10.7% (P< 0.01). CONCLUSION: The EMG-controlled FES system is useful for balance and gait function by increasing muscle symmetry and decreasing muscle coactivation during walking in older adults.

Keywords: Aging, wearable technology, muscle symmetry, gait function

DOI: 10.3233/THC-212849

Journal: Technology and Health Care, vol. 30, no. 2, pp. 423-435, 2022