Masatoshi Nakamura1, Shigeru Sato2, Ryosuke Kiyono2, Kaoru Yahata2, Riku Yoshida2, Taizan Fukaya3, Satoru Nishishita4, Andreas Knorad5. 1. Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan; Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan. Electronic address: masatoshi-nakamura@nuhw.ac.jp. 2. Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan. 3. Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan; Department of Rehabilitation, Kyoto Kujo Hospital, 10 Karahashirajoumoncho, Minami-ku, Kyoto, 601-8453, Japan. 4. Institute of Rehabilitation Science, Tokuyukai Medical Corporation, Osaka, Japan; Kansai Rehabilitation Hospital, Tokuyukai Medical Corporation, Osaka, Japan. 5. Institute of Human Movement Science, Sport and Health, University of Graz, Graz, Austria.
Abstract
BACKGROUND: The association between decreased muscle strength of rate of force development (RFD) immediately after static stretching (SS) and change in muscle stiffness or muscle slack has remained unclear. OBJECTIVE: This study aimed to investigate the association between changes in muscle strength and RFD and muscle stiffness or muscle slack immediately after SS. METHODS: Sixteen healthy male non-athlete volunteers participated in this study. The maximal voluntary contraction torque and shear elastic modulus of medial gastrocnemius muscle were measured before and after 300 s of SS intervention. RESULTS: The results showed that maximal voluntary contraction torque and RFD at 100, 150, and 200 ms decreased significantly after the 300-s SS (p < 0.01). Additionally, shear elastic modulus at 0° (decrease in muscle stiffness) and slack angle decreased (increase in slack length) significantly after the 300-second SS (p < 0.01). However, no significant association was observed between changes in muscle strength and changes in mechanical properties of the MG. CONCLUSION: These results suggested that the decrease in muscle strength and RFD could not be associated with changes in the passive mechanical properties of the medial gastrocnemius muscle.
BACKGROUND: The association between decreased muscle strength of rate of force development (RFD) immediately after static stretching (SS) and change in muscle stiffness or muscle slack has remained unclear. OBJECTIVE: This study aimed to investigate the association between changes in muscle strength and RFD and muscle stiffness or muscle slack immediately after SS. METHODS: Sixteen healthy male non-athlete volunteers participated in this study. The maximal voluntary contraction torque and shear elastic modulus of medial gastrocnemius muscle were measured before and after 300 s of SS intervention. RESULTS: The results showed that maximal voluntary contraction torque and RFD at 100, 150, and 200 ms decreased significantly after the 300-s SS (p < 0.01). Additionally, shear elastic modulus at 0° (decrease in muscle stiffness) and slack angle decreased (increase in slack length) significantly after the 300-second SS (p < 0.01). However, no significant association was observed between changes in muscle strength and changes in mechanical properties of the MG. CONCLUSION: These results suggested that the decrease in muscle strength and RFD could not be associated with changes in the passive mechanical properties of the medial gastrocnemius muscle.
Authors: Masatoshi Nakamura; Riku Yoshida; Shigeru Sato; Kaoru Yahata; Yuta Murakami; Kazuki Kasahara; Taizan Fukaya; Kosuke Takeuchi; João Pedro Nunes; Andreas Konrad Journal: Front Physiol Date: 2021-12-17 Impact factor: 4.566