title: Merging and Fractionation of Muscle Synergy Indicate the Recovery Process in Patients with Hemiplegia: The First Study of Patients after Subacute Stroke.
abstract: Loss of motor coordination is one of the main problems for patients after stroke. Muscle synergy is widely accepted as an indicator of motor coordination. Recently, the characteristics of muscle synergy were quantitatively evaluated using nonnegative matrix factorization (NNMF) with surface electromyography. Previous studies have identified that the number and structure of synergies were associated with motor function in patients after stroke. However, most of these studies had a cross-sectional design, and the changes in muscle synergy during recovery process are not clear. In present study, two consecutive measurements were conducted for subacute patients after stroke and the change of number and structure of muscle synergies during gait were determined using NNMF. Results showed that functional change did not rely on number of synergies in patients after subacute stroke. However, the extent of merging of the synergies was negatively associated with an increase in muscle strength and the range of angle at ankle joint. Our results suggest that the neural changes represented by NNMF were related to the longitudinal change of function and gait pattern and that the merging of synergy is an important marker in patients after subacute stroke.
authors.affiliation: Department of Physical Therapy, Faculty of Health Science, Gumma Paz College, Gunma, Japan.
authors.forename: Yu
authors.identifier: 0000-0003-2882-9884
authors.initials: Y
authors.lastname: Hashiguchi
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Ohata
authors.affiliation: Kansai Rehabilitation Hospital, Osaka, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kitatani
authors.affiliation: Fujita Health University Hospital, Aichi, Japan.
authors.forename: Natsuki
authors.initials: N
authors.lastname: Yamakami
authors.affiliation: Department of Rehabilitation Sciences, Kansai University of Welfare Science, Osaka, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakuma
authors.affiliation: Kuretake Special Support School, Kyoto, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Osako
authors.affiliation: Aijinkai Rehabilitation Hospital, Osaka, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Aga
authors.affiliation: Oita Tobu Hospital, Oita, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Watanabe
authors.affiliation: Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shigehito
authors.initials: S
authors.lastname: Yamada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography / Q000379:methods; D005260:Female; D006429:Hemiplegia / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D020127:Recovery of Function / Q000502:physiology*; D020521:Stroke / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*