Comparison Between High- and Low-Intensity Static Stretching Training Program on Active and Passive Properties of Plantar Flexors

Masatoshi Nakamura; Riku Yoshida; Shigeru Sato; Kaoru Yahata; Yuta Murakami; Kazuki Kasahara; Taizan Fukaya; Kosuke Takeuchi; João Pedro Nunes; Andreas Konrad

doi:10.3389/fphys.2021.796497

Comparison Between High- and Low-Intensity Static Stretching Training Program on Active and Passive Properties of Plantar Flexors

Front Physiol. 2021 Dec 17:12:796497. doi: 10.3389/fphys.2021.796497. eCollection 2021.

Authors

Masatoshi Nakamura^{1

2}, Riku Yoshida¹, Shigeru Sato^{1

3}, Kaoru Yahata¹, Yuta Murakami², Kazuki Kasahara², Taizan Fukaya⁴, Kosuke Takeuchi⁵, João Pedro Nunes⁶, Andreas Konrad⁷

Affiliations

¹ Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata, Japan.
² Department of Physical Therapy, Niigata University of Health and Welfare, Niigata, Japan.
³ Department of Rehabilitation, Matsumura General Hospital, Iwaki, Japan.
⁴ Department of Rehabilitation, Kyoto Kujo Hospital, Kyoto, Japan.
⁵ Department of Physical Therapy, Faculty of Rehabilitation, Kobe International University, Kobe, Japan.
⁶ Metabolism, Nutrition, and Exercise Laboratory, Physical Education and Sport Center, Londrina State University, Londrina, Brazil.
⁷ Institute of Human Movement Science, Sport and Health, University of Graz, Graz, Austria.

Abstract

The purpose of this study was to compare two static stretching (SS) training programs at high-intensity (HI-SS) and low-intensity (LI-SS) on passive and active properties of the plantar flexor muscles. Forty healthy young men were randomly allocated into three groups: HI-SS intervention group (n = 14), LI-SS intervention group (n = 13), and non-intervention control group (n = 13). An 11-point numerical scale (0-10; none to very painful stretching) was used to determine SS intensity. HI-SS and LI-SS stretched at 6-7 and 0-1 intensities, respectively, both in 3 sets of 60 s, 3×/week, for 4 weeks. Dorsiflexion range of motion (ROM), gastrocnemius muscle stiffness, muscle strength, drop jump height, and muscle architecture were assessed before and after SS training program. The HI-SS group improved more than LI-SS in ROM (40 vs. 15%) and decreased muscle stiffness (-57 vs. -24%), while no significant change was observed for muscle strength, drop jump height, and muscle architecture in both groups. The control group presented no significant change in any variable. Performing HI-SS is more effective than LI-SS for increasing ROM and decreasing muscle stiffness of plantar flexor muscles following a 4-week training period in young men. However, SS may not increase muscle strength or hypertrophy, regardless of the stretching discomfort intensity.

Keywords: ankle plantar flexors; extended-field-of-view; fascicle length; muscle thickness; pennation angle; resistance training; stretch training.