Ryosuke Kitatani1, Koji Ohata2, Yumi Aga3, Yuki Mashima4, Yu Hashiguchi5, Masanori Wakida6, Ayaka Maeda2, Shigehito Yamada2. 1. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Japan Society for the Promotion of Science, Tokyo, Japan. Electronic address: kitatani.ryosuke.88x@st.kyoto-u.ac.jp. 2. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 3. Aijinkai Rehabilitation Hospital, Osaka, Japan. 4. Department of Rehabilitation, Kansai Medical University Hirakata Hospital, Osaka, Japan. 5. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Japan Society for the Promotion of Science, Tokyo, Japan. 6. Department of Physical Therapy, Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan; Department of Rehabilitation, Kansai Medical University Hirakata Hospital, Osaka, Japan.
Abstract
OBJECTIVE: The objective of this study was to investigate the descending neural drive to ankle muscles during gait in stroke patients using a coherence analysis of surface electromyographic (EMG) recordings and the relationships of the drive with clinical functions. METHODS: EMG recordings of the paired tibialis anterior (TA), medial and lateral gastrocnemius (MG and LG), and TA-LG muscles were used to calculate intramuscular, synergistic, and agonist-antagonist muscle coherence, respectively, in 11 stroke patients and 9 healthy controls. Paretic motor function, sensory function, spasticity, ankle muscle strength, and gait performance were evaluated. RESULTS: Paretic TA-TA and MG-LG beta band (15-30 Hz) coherences were significantly lower compared with the non-paretic side and controls. TA-LG beta band coherence was significantly higher on both sides compared with controls. Paretic TA-TA beta band coherence positively correlated with gait speed, and paretic TA-LG beta band coherence negatively correlated with paretic ankle plantar flexor muscle strength. CONCLUSIONS: The intramuscular and synergistic muscle neural drives were reduced during gait on the paretic side in stroke patients. The agonist-antagonist muscle neural drive was increased to compensate for paretic ankle muscle weakness. SIGNIFICANCE: Descending neural drive reorganization to agonist-antagonist muscles is important for patients with paretic ankle muscle weakness.
OBJECTIVE: The objective of this study was to investigate the descending neural drive to ankle muscles during gait in strokepatients using a coherence analysis of surface electromyographic (EMG) recordings and the relationships of the drive with clinical functions. METHODS: EMG recordings of the paired tibialis anterior (TA), medial and lateral gastrocnemius (MG and LG), and TA-LG muscles were used to calculate intramuscular, synergistic, and agonist-antagonist muscle coherence, respectively, in 11 strokepatients and 9 healthy controls. Paretic motor function, sensory function, spasticity, ankle muscle strength, and gait performance were evaluated. RESULTS: Paretic TA-TA and MG-LG beta band (15-30 Hz) coherences were significantly lower compared with the non-paretic side and controls. TA-LG beta band coherence was significantly higher on both sides compared with controls. Paretic TA-TA beta band coherence positively correlated with gait speed, and paretic TA-LG beta band coherence negatively correlated with paretic ankle plantar flexor muscle strength. CONCLUSIONS: The intramuscular and synergistic muscle neural drives were reduced during gait on the paretic side in strokepatients. The agonist-antagonist muscle neural drive was increased to compensate for paretic ankle muscle weakness. SIGNIFICANCE: Descending neural drive reorganization to agonist-antagonist muscles is important for patients with paretic ankle muscle weakness.