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ORIGINAL ARTICLES
The effect of low-level laser irradiation on muscle tension and hardness compared among three wavelengths Takahisa Yonezu 1, Shinichi Kogure 2
1: Graduate School of Sports Science, Waseda University, Japan 2: Department of Bioinformatics, Graduate school of Engineering, Soka University, Japan
Background and Aims: It has been reported that low-level laser irradiation (LLLI) can influence muscle tissue by retarding attenuation of muscle tension. Since the efficacy of LLLI on the effects of muscle contraction remains unclear, we examined in an in vivo animal model whether LLLI affects both muscle tension and muscle hardness in a wavelength-dependent manner, using the rat gastrocnemius muscle. Material and Methods: Forty Sprague-Dawley adult rats were used. Under pentobarbital sodium anesthesia, their gastrocnemius muscle and tibial nerve were exteriorized. Diode LLLI systems delivering 3 wavelengths (405, 532, and 808 nm; 100 mW output) were used. Ten sets of tetanus (tetanic contractions) were delivered to the tibial nerve followed by a brief rest or LLLI for 15 s and an additional 7 sets of tetanus with an inter-stimulus interval of 5 min. The muscle tension and muscle hardness were measured with a tension transducer and hardness meter, respectively. Results: 405 nm LLLI did not influence either muscle tension or hardness. 532 nm LLLI significantly improved the maintenance of muscle tension compared with the 808 nm group (P
ORIGINAL ARTICLES
The effect of low-level laser irradiation on muscle tension and hardness compared among three wavelengths Takahisa Yonezu 1, Shinichi Kogure 2
1: Graduate School of Sports Science, Waseda University, Japan 2: Department of Bioinformatics, Graduate school of Engineering, Soka University, Japan
Background and Aims: It has been reported that low-level laser irradiation (LLLI) can influence muscle tissue by retarding attenuation of muscle tension. Since the efficacy of LLLI on the effects of muscle contraction remains unclear, we examined in an in vivo animal model whether LLLI affects both muscle tension and muscle hardness in a wavelength-dependent manner, using the rat gastrocnemius muscle. Material and Methods: Forty Sprague-Dawley adult rats were used. Under pentobarbital sodium anesthesia, their gastrocnemius muscle and tibial nerve were exteriorized. Diode LLLI systems delivering 3 wavelengths (405, 532, and 808 nm; 100 mW output) were used. Ten sets of tetanus (tetanic contractions) were delivered to the tibial nerve followed by a brief rest or LLLI for 15 s and an additional 7 sets of tetanus with an inter-stimulus interval of 5 min. The muscle tension and muscle hardness were measured with a tension transducer and hardness meter, respectively. Results: 405 nm LLLI did not influence either muscle tension or hardness. 532 nm LLLI significantly improved the maintenance of muscle tension compared with the 808 nm group (P
