Raki Kawama1,2, Ko Yanase3,4, Tatsuya Hojo1,3, Taku Wakahara5,6. 1. Graduate School of Health and Sports Science, Doshisha University, Kyoto, Japan. 2. Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan. 3. Faculty of Health and Sports Science, Doshisha University, Kyoto, Japan. 4. Human Health Sciences, Graduate School of Medicine, Kyoto University, Kyoto, Japan. 5. Faculty of Health and Sports Science, Doshisha University, Kyoto, Japan. twakahar@mail.doshisha.ac.jp. 6. Human Performance Laboratory, Waseda University, Saitama, Japan. twakahar@mail.doshisha.ac.jp.
Abstract
PURPOSE: Recent studies raise an interesting possibility that resistance exercise also decreases passive muscle stiffness, as does stretching exercise. However, little is known about how program variables of resistance exercise acutely influence muscle stiffness. We aimed to examine the acute changes in passive stiffness of the individual hamstring muscles after resistance exercises using different combinations of contraction modes and ranges of motion (ROMs). METHODS: Thirteen healthy young male participants performed three sessions of resistance exercises that comprised stiff-leg deadlift with different contraction modes and exercise ROMs on separate days as follows: (1) eccentric contractions with a wide exercise ROM (EW); (2) eccentric contractions with a narrow exercise ROM (EN); and (3) concentric contractions with a wide exercise ROM (CW). Maximal joint ROM, passive torque, shear modulus of the individual hamstring muscles, and maximal isometric torque of knee flexion were measured before and 3 min, 30 min, and 60 min after completing each session. RESULTS: The shear modulus of the semimembranosus was significantly lower at 3 min post-exercise (121.8 ± 16.0 kPa) than at pre-exercise (129.0 ± 18.9 kPa, p = 0.021, r = 0.45) in EW, but not in EN or CW. There were no significant changes in the shear moduli of the biceps femoris long head or the semitendinosus at any timepoint in any exercise protocols. CONCLUSIONS: The present results suggest that the combination of eccentric contraction and wide ROM during resistance exercise has the potential to acutely decrease passive stiffness (shear modulus) of a specific muscle.
PURPOSE: Recent studies raise an interesting possibility that resistance exercise also decreases passive muscle stiffness, as does stretching exercise. However, little is known about how program variables of resistance exercise acutely influence muscle stiffness. We aimed to examine the acute changes in passive stiffness of the individual hamstring muscles after resistance exercises using different combinations of contraction modes and ranges of motion (ROMs). METHODS: Thirteen healthy young male participants performed three sessions of resistance exercises that comprised stiff-leg deadlift with different contraction modes and exercise ROMs on separate days as follows: (1) eccentric contractions with a wide exercise ROM (EW); (2) eccentric contractions with a narrow exercise ROM (EN); and (3) concentric contractions with a wide exercise ROM (CW). Maximal joint ROM, passive torque, shear modulus of the individual hamstring muscles, and maximal isometric torque of knee flexion were measured before and 3 min, 30 min, and 60 min after completing each session. RESULTS: The shear modulus of the semimembranosus was significantly lower at 3 min post-exercise (121.8 ± 16.0 kPa) than at pre-exercise (129.0 ± 18.9 kPa, p = 0.021, r = 0.45) in EW, but not in EN or CW. There were no significant changes in the shear moduli of the biceps femoris long head or the semitendinosus at any timepoint in any exercise protocols. CONCLUSIONS: The present results suggest that the combination of eccentric contraction and wide ROM during resistance exercise has the potential to acutely decrease passive stiffness (shear modulus) of a specific muscle.
Authors: Germanna M Barbosa; Gabriel S Trajano; Glauko A F Dantas; Bianca R Silva; Wouber H Brito Vieira Journal: J Strength Cond Res Date: 2020-07 Impact factor: 3.775
Authors: Anne A G Aune; Chris Bishop; Anthony N Turner; Kostas Papadopoulos; Sarah Budd; Mark Richardson; Sean J Maloney Journal: J Sports Sci Date: 2018-06-12 Impact factor: 3.337