The Experts below are selected from a list of 660 Experts worldwide ranked by ideXlab platform

Akira Saito - One of the best experts on this subject based on the ideXlab platform.

  • Muscle synergies are consistent across level and uphill treadmill running
    Scientific Reports, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    This study aimed to identify Muscle synergies of the lower limb during treadmill running on level and inclined ground. Eight subjects ran on a treadmill at three speeds (2.5, 3.3, and 4.1 m/s) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including deeper Muscles such as vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying a non-negative matrix factorization algorithm, and relative co-activations across Muscles and the temporal recruitment pattern were identified by Muscle synergy vector and synergy activation coefficient, respectively. The scalar product between pairs of synergy vectors and synergy activation coefficients during level and uphill running conditions were analyzed as a similarity index, with values above 0.8 recognized as similar. Approximately 4 Muscle synergies controlled the majority of variability in 10 EMGs during running, and were common between level and uphill conditions. At each running speed, inter-condition similarity was observed in synergy vector (r > 0.83) and synergy activation coefficients (r > 0.84) at each type of synergy. These results suggest that types of synergy are consistent between level and uphill running.

  • similarity of Muscle synergies extracted from the lower limb including the deep Muscles between level and uphill treadmill walking
    Gait & Posture, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    Abstract This study aimed to examine Muscle synergies involving the deeper Muscles of the lower limb during level and uphill treadmill walking. Seven men and five women walked on a treadmill at three speeds (60, 80, and 100 m/min) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying non-negative matrix factorization, and the relative co-activation across Muscles and the temporal information of synergy recruitment were identified by the Muscle synergy vector and synergy activation coefficient, respectively. Correlation coefficients between a pair of synergy vectors during level and uphill walking were analyzed as a similarity index, with the similarity criterion at r  = 0.76. Changes in synergy activation coefficients between the walking conditions were evaluated by cross-correlation analysis. The mean number of synergies ranged from 3.8 to 4.0 across all conditions, and they were not significantly different between level and uphill walking conditions. Similarity between walking conditions was high ( r  > 0.76) for three Muscle synergies, but not for one synergy that mainly consisted of the quadriceps femoris. The inter-condition similarity of the synergy activation coefficients was high for the four synergies, and a significant lag time for synergy 2 , which consisted mainly of the activity of medial gastrocnemius, was found at 60 and 80 m/min. The Muscle synergies extracted from the lower limb involving the deeper Muscles appear to be consistent during level and uphill treadmill walking.

Yoshinobu Ohira - One of the best experts on this subject based on the ideXlab platform.

  • region specific responses of Adductor Longus Muscle to gravitational load dependent activity in wistar hannover rats
    PLOS ONE, 2011
    Co-Authors: Takashi Ohira, Akihiko Ogura, Fuminori Kawano, Naoya Nakai, Masahiro Terada, Yoshinobu Ohira
    Abstract:

    Response of Adductor Longus (AL) Muscle to gravitational unloading and reloading was studied. Male Wistar Hannover rats (5-wk old) were hindlimb-unloaded for 16 days with or without 16-day ambulation recovery. The electromyogram (EMG) activity in AL decreased after acute unloading, but that in the rostral region was even elevated during continuous unloading. The EMG levels in the caudal region gradually increased up to 6th day, but decreased again. Approximately 97% of fibers in the caudal region were pure type I at the beginning of experiment. Mean percentage of type I fibers in the rostral region was 61% and that of type I+II and II fiber was 14 and 25%, respectively. The percent type I fibers decreased and de novo appearance of type I+II was noted after unloading. But the fiber phenotype in caudal, not rostral and middle, region was normalized after 16-day ambulation. Pronounced atrophy after unloading and re-growth following ambulation was noted in type I fibers of the caudal region. Sarcomere length in the caudal region was passively shortened during unloading, but that in the rostral region was unchanged or even stretched slightly. Growth-associated increase of myonuclear number seen in the caudal region of control rats was inhibited by unloading. Number of mitotic active satellite cells decreased after unloading only in the caudal region. It was indicated that the responses of fiber properties in AL to unloading and reloading were closely related to the region-specific neural and mechanical activities, being the caudal region more responsive.

Hiroshi Akima - One of the best experts on this subject based on the ideXlab platform.

  • Muscle synergies are consistent across level and uphill treadmill running
    Scientific Reports, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    This study aimed to identify Muscle synergies of the lower limb during treadmill running on level and inclined ground. Eight subjects ran on a treadmill at three speeds (2.5, 3.3, and 4.1 m/s) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including deeper Muscles such as vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying a non-negative matrix factorization algorithm, and relative co-activations across Muscles and the temporal recruitment pattern were identified by Muscle synergy vector and synergy activation coefficient, respectively. The scalar product between pairs of synergy vectors and synergy activation coefficients during level and uphill running conditions were analyzed as a similarity index, with values above 0.8 recognized as similar. Approximately 4 Muscle synergies controlled the majority of variability in 10 EMGs during running, and were common between level and uphill conditions. At each running speed, inter-condition similarity was observed in synergy vector (r > 0.83) and synergy activation coefficients (r > 0.84) at each type of synergy. These results suggest that types of synergy are consistent between level and uphill running.

  • similarity of Muscle synergies extracted from the lower limb including the deep Muscles between level and uphill treadmill walking
    Gait & Posture, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    Abstract This study aimed to examine Muscle synergies involving the deeper Muscles of the lower limb during level and uphill treadmill walking. Seven men and five women walked on a treadmill at three speeds (60, 80, and 100 m/min) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying non-negative matrix factorization, and the relative co-activation across Muscles and the temporal information of synergy recruitment were identified by the Muscle synergy vector and synergy activation coefficient, respectively. Correlation coefficients between a pair of synergy vectors during level and uphill walking were analyzed as a similarity index, with the similarity criterion at r  = 0.76. Changes in synergy activation coefficients between the walking conditions were evaluated by cross-correlation analysis. The mean number of synergies ranged from 3.8 to 4.0 across all conditions, and they were not significantly different between level and uphill walking conditions. Similarity between walking conditions was high ( r  > 0.76) for three Muscle synergies, but not for one synergy that mainly consisted of the quadriceps femoris. The inter-condition similarity of the synergy activation coefficients was high for the four synergies, and a significant lag time for synergy 2 , which consisted mainly of the activity of medial gastrocnemius, was found at 60 and 80 m/min. The Muscle synergies extracted from the lower limb involving the deeper Muscles appear to be consistent during level and uphill treadmill walking.

Ryosuke Ando - One of the best experts on this subject based on the ideXlab platform.

  • Muscle synergies are consistent across level and uphill treadmill running
    Scientific Reports, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    This study aimed to identify Muscle synergies of the lower limb during treadmill running on level and inclined ground. Eight subjects ran on a treadmill at three speeds (2.5, 3.3, and 4.1 m/s) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including deeper Muscles such as vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying a non-negative matrix factorization algorithm, and relative co-activations across Muscles and the temporal recruitment pattern were identified by Muscle synergy vector and synergy activation coefficient, respectively. The scalar product between pairs of synergy vectors and synergy activation coefficients during level and uphill running conditions were analyzed as a similarity index, with values above 0.8 recognized as similar. Approximately 4 Muscle synergies controlled the majority of variability in 10 EMGs during running, and were common between level and uphill conditions. At each running speed, inter-condition similarity was observed in synergy vector (r > 0.83) and synergy activation coefficients (r > 0.84) at each type of synergy. These results suggest that types of synergy are consistent between level and uphill running.

  • similarity of Muscle synergies extracted from the lower limb including the deep Muscles between level and uphill treadmill walking
    Gait & Posture, 2018
    Co-Authors: Aya Tomita, Kohei Watanabe, Ryosuke Ando, Akira Saito, Hiroshi Akima
    Abstract:

    Abstract This study aimed to examine Muscle synergies involving the deeper Muscles of the lower limb during level and uphill treadmill walking. Seven men and five women walked on a treadmill at three speeds (60, 80, and 100 m/min) and two grades (level and 10% grade). Surface electromyographic (EMG) signals were recorded from 10 Muscles of the lower limb, including vastus intermedius, Adductor magnus, and Adductor Longus. Muscle synergies were extracted applying non-negative matrix factorization, and the relative co-activation across Muscles and the temporal information of synergy recruitment were identified by the Muscle synergy vector and synergy activation coefficient, respectively. Correlation coefficients between a pair of synergy vectors during level and uphill walking were analyzed as a similarity index, with the similarity criterion at r  = 0.76. Changes in synergy activation coefficients between the walking conditions were evaluated by cross-correlation analysis. The mean number of synergies ranged from 3.8 to 4.0 across all conditions, and they were not significantly different between level and uphill walking conditions. Similarity between walking conditions was high ( r  > 0.76) for three Muscle synergies, but not for one synergy that mainly consisted of the quadriceps femoris. The inter-condition similarity of the synergy activation coefficients was high for the four synergies, and a significant lag time for synergy 2 , which consisted mainly of the activity of medial gastrocnemius, was found at 60 and 80 m/min. The Muscle synergies extracted from the lower limb involving the deeper Muscles appear to be consistent during level and uphill treadmill walking.

Takashi Ohira - One of the best experts on this subject based on the ideXlab platform.

  • region specific responses of Adductor Longus Muscle to gravitational load dependent activity in wistar hannover rats
    PLOS ONE, 2011
    Co-Authors: Takashi Ohira, Akihiko Ogura, Fuminori Kawano, Naoya Nakai, Masahiro Terada, Yoshinobu Ohira
    Abstract:

    Response of Adductor Longus (AL) Muscle to gravitational unloading and reloading was studied. Male Wistar Hannover rats (5-wk old) were hindlimb-unloaded for 16 days with or without 16-day ambulation recovery. The electromyogram (EMG) activity in AL decreased after acute unloading, but that in the rostral region was even elevated during continuous unloading. The EMG levels in the caudal region gradually increased up to 6th day, but decreased again. Approximately 97% of fibers in the caudal region were pure type I at the beginning of experiment. Mean percentage of type I fibers in the rostral region was 61% and that of type I+II and II fiber was 14 and 25%, respectively. The percent type I fibers decreased and de novo appearance of type I+II was noted after unloading. But the fiber phenotype in caudal, not rostral and middle, region was normalized after 16-day ambulation. Pronounced atrophy after unloading and re-growth following ambulation was noted in type I fibers of the caudal region. Sarcomere length in the caudal region was passively shortened during unloading, but that in the rostral region was unchanged or even stretched slightly. Growth-associated increase of myonuclear number seen in the caudal region of control rats was inhibited by unloading. Number of mitotic active satellite cells decreased after unloading only in the caudal region. It was indicated that the responses of fiber properties in AL to unloading and reloading were closely related to the region-specific neural and mechanical activities, being the caudal region more responsive.

  • Region-Specific Responses of Adductor Longus Muscle to Gravitational Load-Dependent Activity in Wistar Hannover Rats
    2011
    Co-Authors: Takashi Ohira, Fuminori Kawano, Naoya Nakai, Masahiro Terada, Akihiko Ogura
    Abstract:

    Response of Adductor Longus (AL) Muscle to gravitational unloading and reloading was studied. Male Wistar Hannover rats (5-wk old) were hindlimb-unloaded for 16 days with or without 16-day ambulation recovery. The electromyogram (EMG) activity in AL decreased after acute unloading, but that in the rostral region was even elevated during continuous unloading. The EMG levels in the caudal region gradually increased up to 6th day, but decreased again. Approximately 97% of fibers in the caudal region were pure type I at the beginning of experiment. Mean percentage of type I fibers in the rostral region was 61 % and that of type I+II and II fiber was 14 and 25%, respectively. The percent type I fibers decreased and de novo appearance of type I+II was noted after unloading. But the fiber phenotype in caudal, not rostral and middle, region was normalized after 16-day ambulation. Pronounced atrophy after unloading and re-growth following ambulation was noted in type I fibers of the caudal region. Sarcomere length in the caudal region was passively shortened during unloading, but that in the rostral region was unchanged or even stretched slightly. Growth-associated increase of myonuclear number seen in the caudal region of control rats was inhibited by unloading. Number of mitotic active satellite cells decreased after unloading only in the caudal region. It was indicated that the responses of fiber properties in AL to unloading and reloadin