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Kazunori Nosaka - One of the best experts on this subject based on the ideXlab platform.

  • Damage protective effects conferred by low-intensity eccentric contractions on arm, leg and trunk muscles
    European Journal of Applied Physiology, 2019
    Co-Authors: Min-jyue Huang, Kazunori Nosaka, Hsin Lian Chen, Ho-seng Wang, Kuo-wei Tseng, Tai-ying Chou, Trevor C Chen
    Abstract:

    Purpose Low-intensity eccentric contractions with a load corresponding to 10% of maximal voluntary isometric contraction strength (10% EC) attenuate muscle damage in a subsequent bout of higher-intensity eccentric contractions performed within 2 weeks for the elbow Flexors, Knee Flexors and Knee extensors. However, it is not known whether this strategy could be applied to other muscles. This study investigated whether 10% EC would confer damage protective effect on high-intensity eccentric contractions (80% EC) for nine different muscle groups. Methods Untrained young men were placed to an experimental or a control group ( n  = 12/group). Experimental group performed 50 eccentric contractions with a load corresponding to 10% EC at 2 days prior to 50 eccentric contractions with 80% EC for the elbow Flexors and extensors, pectoralis, Knee Flexors and extensors, plantar Flexors, latissimus, abdominis and erector spinae. Control group performed 80% EC without 10% EC. Changes in maximal voluntary isometric contraction strength (MVC) and muscle soreness, plasma creatine kinase (CK) activity and myoglobin concentration after 80% EC were compared between groups by a mixed-factor ANOVA. Results MVC recovered faster (e.g., 6–31% greater MVC at 5 days post-exercise), and peak muscle soreness was 36–54% lower for Experimental than Control group for the nine muscles ( P  

  • contralateral repeated bout effect of the Knee Flexors
    Medicine and Science in Sports and Exercise, 2017
    Co-Authors: Trevor C Chen, Ming Ju Lin, Hsin Lian Chen, Kazunori Nosaka
    Abstract:

    ABSTRACTPurposeEccentric exercise of the elbow Flexors (EF) confers protective effect against muscle damage of the same exercise performed by the opposite arm at 1, 7, or 28 d later. This is known as the contralateral repeated bout effect (CL-RBE), but it is not known whether CL-RBE is evident for t

  • changes in force and stiffness after static stretching of eccentrically damaged hamstrings
    European Journal of Applied Physiology, 2015
    Co-Authors: Shigeyuki Suzuki, Shingo Matsuo, Masahiro Iwata, Genki Hatano, Kazunori Nosaka
    Abstract:

    This study compared responses to static stretching between eccentrically damaged and non-damaged muscles. Twelve young men performed 60 maximum Knee flexor eccentric contractions of one leg, and received a 300-s continuous passive static stretching at tolerable intensity without pain to both Knee Flexors at 2 and 4 days after the eccentric exercise. Range of motion (ROM) and passive stiffness during Knee extension, passive torque at onset of pain (PT), maximum voluntary isometric (MVC-ISO) and isokinetic concentric contraction torque (MVC-CON), and visual analogue scale (VAS) for muscle soreness were measured before, immediately after, 60 min, 2 and 4 days after exercise as well as before, immediately after, 20 and 60 min after the stretching. Changes in these variables after eccentric exercise and stretching were compared between limbs. The eccentric exercise decreased MVC-ISO, MVC-CON, ROM and PT, and increased passive stiffness and VAS (p < 0.05), suggesting that muscle damage was induced to the Knee Flexors. ROM and PT increased after stretching for both limbs; however, the magnitude of the increase was greater (p < 0.05) for the damaged than non-damaged limb. Passive stiffness decreased for both limbs similarly (4–7 %) at immediately after stretching (p < 0.05). Significant decreases in MVC-ISO torque (7–11 %) after stretching were observed only for the non-damaged limb (p < 0.05), but MVC-CON torque did not change after stretching for both limbs. VAS decreased for the exercised limb after stretching (p < 0.05). These results suggest that the static stretching at tolerable intensity without pain produced greater positive effects on damaged than non-damaged muscles.

  • effects of eccentric exercise on optimum length of the Knee Flexors and extensors during the preseason in professional soccer players
    Physical Therapy in Sport, 2010
    Co-Authors: Matt Brughelli, John B. Cronin, Kazunori Nosaka, Jurdan Mendiguchia, Fernando Idoate, Asier Los Arcos
    Abstract:

    Abstract Objective To assess the effects of eccentric exercise on optimum lengths of the Knee Flexors and extensors during the preseason in professional soccer. Design Twenty-eight athletes from a professional Spanish soccer team (Division II) were randomly assigned to an eccentric exercise intervention group (EG) or a control group (CG). Over the four-week period two athletes from the control group suffered RF injuries and two athletes were contracted by other clubs. After these exclusions, both groups (EG, n=13; and CG, n=11) performed regular soccer training during the four-week preseason period. Results After the four weeks, the optimum lengths of the Knee Flexors were significantly (P Conclusion Eccentric exercise can increase the optimum lengths of both the Knee extensors and Knee extensors Flexors during the preseason in professional soccer.

  • Muscle architecture and optimum angle of the Knee Flexors and extensors: a comparison between cyclists and Australian Rules football players.
    Journal of strength and conditioning research, 2010
    Co-Authors: Matt Brughelli, John B. Cronin, Kazunori Nosaka
    Abstract:

    Brughelli, M, Cronin, J, and Nosaka, K. Muscle architecture and optimum angle of the Knee Flexors and extensors: a comparison between cyclists and Australian Rules football players. J Strength Cond Res 24(3): 717‐721, 2010—The purpose of this study was to investigate differences in optimum angle of peak torque (Knee extensors and Flexors) and muscle architecture (vastus lateralis) between 9 cyclists and 9 Australian Rules football (ARF) players. The angles of peak torque of the ARF players were significantly (p , 0.05) greater during Knee extension (70.8 6 3.5 vs. 66.6 6 5.9) and smaller during Knee flexion (26.2 6 2.9 vs. 32.3 6 3.8) compared with the cyclists. The ARF players had significantly (p , 0.05) smaller pennation angles (19.3 6 2.0 vs. 24.9 6 2.5) and longer fascicle lengths (7.9 6 0.7 vs. 6.2 6 0.8 cm) in comparison with the cyclists. There were no significant differences between groups regarding muscle thickness or peak torque ratios between the quadriceps and hamstrings. Muscle architectural changes associated with resistance strength training need to be investigated so that the effects of training on architecture and functional performance can be determined.

J W Yates - One of the best experts on this subject based on the ideXlab platform.

  • moderate static stretching and torque production of the Knee Flexors
    Journal of Strength and Conditioning Research, 2010
    Co-Authors: Molly Rebecca Winke, Nathaniel B Jones, Christopher G Berger, J W Yates
    Abstract:

    Recent studies have suggested that acute static stretching (SS) decreases muscular strength and performance, particularly of the Knee extensors. The purpose of this study was to investigate the effect of SS on peak concentric and eccentric torque production in the Knee Flexors. Subjects (13 women and 16 men) were tested for isokinetic concentric (CON) and eccentric (ECC) peak torque at 2 velocities (60 and 210 degrees x s(-1)) before and after a 3-minute Knee flexor SS protocol. Subjects also underwent a control day in which the isokinetic pre- and posttests were separated by 10 minutes of sitting rather than stretching. A sit and reach test was administered on both days to assess changes in flexibility that occurred as a result of the stretching or control protocols. The change in flexibility was significantly greater after stretching than after sitting. Changes in peak torque were not significantly different between the stretching and control conditions for either velocity or contraction type. Compared with the control condition, SS of the Knee Flexors before maximal isokinetic testing does not lead to significantly diminished CON or ECC torque output at slow or fast contraction velocities. These data suggest that moderate SS does not impact the performance of all muscle groups.

Shingo Matsuo - One of the best experts on this subject based on the ideXlab platform.

  • changes in force and stiffness after static stretching of eccentrically damaged hamstrings
    European Journal of Applied Physiology, 2015
    Co-Authors: Shigeyuki Suzuki, Shingo Matsuo, Masahiro Iwata, Genki Hatano, Kazunori Nosaka
    Abstract:

    This study compared responses to static stretching between eccentrically damaged and non-damaged muscles. Twelve young men performed 60 maximum Knee flexor eccentric contractions of one leg, and received a 300-s continuous passive static stretching at tolerable intensity without pain to both Knee Flexors at 2 and 4 days after the eccentric exercise. Range of motion (ROM) and passive stiffness during Knee extension, passive torque at onset of pain (PT), maximum voluntary isometric (MVC-ISO) and isokinetic concentric contraction torque (MVC-CON), and visual analogue scale (VAS) for muscle soreness were measured before, immediately after, 60 min, 2 and 4 days after exercise as well as before, immediately after, 20 and 60 min after the stretching. Changes in these variables after eccentric exercise and stretching were compared between limbs. The eccentric exercise decreased MVC-ISO, MVC-CON, ROM and PT, and increased passive stiffness and VAS (p < 0.05), suggesting that muscle damage was induced to the Knee Flexors. ROM and PT increased after stretching for both limbs; however, the magnitude of the increase was greater (p < 0.05) for the damaged than non-damaged limb. Passive stiffness decreased for both limbs similarly (4–7 %) at immediately after stretching (p < 0.05). Significant decreases in MVC-ISO torque (7–11 %) after stretching were observed only for the non-damaged limb (p < 0.05), but MVC-CON torque did not change after stretching for both limbs. VAS decreased for the exercised limb after stretching (p < 0.05). These results suggest that the static stretching at tolerable intensity without pain produced greater positive effects on damaged than non-damaged muscles.

Molly Rebecca Winke - One of the best experts on this subject based on the ideXlab platform.

  • moderate static stretching and torque production of the Knee Flexors
    Journal of Strength and Conditioning Research, 2010
    Co-Authors: Molly Rebecca Winke, Nathaniel B Jones, Christopher G Berger, J W Yates
    Abstract:

    Recent studies have suggested that acute static stretching (SS) decreases muscular strength and performance, particularly of the Knee extensors. The purpose of this study was to investigate the effect of SS on peak concentric and eccentric torque production in the Knee Flexors. Subjects (13 women and 16 men) were tested for isokinetic concentric (CON) and eccentric (ECC) peak torque at 2 velocities (60 and 210 degrees x s(-1)) before and after a 3-minute Knee flexor SS protocol. Subjects also underwent a control day in which the isokinetic pre- and posttests were separated by 10 minutes of sitting rather than stretching. A sit and reach test was administered on both days to assess changes in flexibility that occurred as a result of the stretching or control protocols. The change in flexibility was significantly greater after stretching than after sitting. Changes in peak torque were not significantly different between the stretching and control conditions for either velocity or contraction type. Compared with the control condition, SS of the Knee Flexors before maximal isokinetic testing does not lead to significantly diminished CON or ECC torque output at slow or fast contraction velocities. These data suggest that moderate SS does not impact the performance of all muscle groups.

Masahiro Iwata - One of the best experts on this subject based on the ideXlab platform.

  • changes in force and stiffness after static stretching of eccentrically damaged hamstrings
    European Journal of Applied Physiology, 2015
    Co-Authors: Shigeyuki Suzuki, Shingo Matsuo, Masahiro Iwata, Genki Hatano, Kazunori Nosaka
    Abstract:

    This study compared responses to static stretching between eccentrically damaged and non-damaged muscles. Twelve young men performed 60 maximum Knee flexor eccentric contractions of one leg, and received a 300-s continuous passive static stretching at tolerable intensity without pain to both Knee Flexors at 2 and 4 days after the eccentric exercise. Range of motion (ROM) and passive stiffness during Knee extension, passive torque at onset of pain (PT), maximum voluntary isometric (MVC-ISO) and isokinetic concentric contraction torque (MVC-CON), and visual analogue scale (VAS) for muscle soreness were measured before, immediately after, 60 min, 2 and 4 days after exercise as well as before, immediately after, 20 and 60 min after the stretching. Changes in these variables after eccentric exercise and stretching were compared between limbs. The eccentric exercise decreased MVC-ISO, MVC-CON, ROM and PT, and increased passive stiffness and VAS (p < 0.05), suggesting that muscle damage was induced to the Knee Flexors. ROM and PT increased after stretching for both limbs; however, the magnitude of the increase was greater (p < 0.05) for the damaged than non-damaged limb. Passive stiffness decreased for both limbs similarly (4–7 %) at immediately after stretching (p < 0.05). Significant decreases in MVC-ISO torque (7–11 %) after stretching were observed only for the non-damaged limb (p < 0.05), but MVC-CON torque did not change after stretching for both limbs. VAS decreased for the exercised limb after stretching (p < 0.05). These results suggest that the static stretching at tolerable intensity without pain produced greater positive effects on damaged than non-damaged muscles.