title: Acute Effects of the Different Intensity of Static Stretching on Flexibility and Isometric Muscle Force.
abstract: Kataura, S, Suzuki, S, Matsuo, S, Hatano, G, Iwata, M, Yokoi, K, Tsuchida, W, Banno, Y, and Asai, Y. Acute effects of the different intensity of static stretching on flexibility and isometric muscle force. J Strength Cond Res 31(12): 3403-3410, 2017-In various fields, static stretching is commonly performed to improve flexibility, whereas the acute effects of different stretch intensities are unclear. Therefore, we investigated the acute effects of different stretch intensities on flexibility and muscle force. Eighteen healthy participants (9 men and 9 women) performed 180-second static stretches of the right hamstrings at 80, 100, and 120% of maximum tolerable intensity without stretching pain, in random order. The following outcomes were assessed as markers of lower limb function and flexibility: static passive torque (SPT), range of motion (ROM), passive joint (muscle-tendon) stiffness, passive torque (PT) at onset of pain, and isometric muscle force. Static passive torque was significantly decreased after all stretching intensities (p ≤ 0.05). Compared with before stretching at 100 and 120% intensities, ROM and PT were significantly increased after stretching (p ≤ 0.05), and passive stiffness (p = 0.05) and isometric muscle force (p ≤ 0.05) were significantly decreased. In addition, ROM was significantly greater after stretching at 100 and 120% than at 80%, and passive stiffness was significantly lower after 120% than after 80% (p ≤ 0.05). However, all measurements except SPT were unchanged after 80% intensity. There was a weak positive correlation between the intensities of stretching and the relative change for SPT (p ≤ 0.05), a moderate positive correlation with ROM (p ≤ 0.05), and a moderate positive correlation with passive stiffness (p ≤ 0.05). These results indicate that static stretching at greater intensity is more effective for increasing ROM and decreasing passive muscle-tendon stiffness.
authors.affiliation: Department of Rehabilitation, Kobe Century Memorial Hospital, Kobe, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kataura
authors.affiliation: Program in Physical and Occupational Therapy, Graduate School of Medicine, Nagoya University, Nagoya, Japan.
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Program in Physical and Occupational Therapy, Graduate School of Medicine, Nagoya University, Nagoya, Japan.|Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Matsuo
authors.affiliation: ASICS Corporation, Institution of Sport Science, Kobe, Japan.
authors.forename: Genki
authors.initials: G
authors.lastname: Hatano
authors.affiliation: Program in Physical and Occupational Therapy, Graduate School of Medicine, Nagoya University, Nagoya, Japan.|Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Iwata
authors.affiliation: Department of Rehabilitation, Kameda Medical Center, Kamogawa, Japan.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Yokoi
authors.affiliation: Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan.
authors.forename: Wakako
authors.initials: W
authors.lastname: Tsuchida
authors.affiliation: Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Banno
authors.affiliation: Department of Rehabilitation, Faculty of Health Sciences, Nihon Fukushi University, Handa, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Asai
mesh_terms: D005260:Female; D000070633:Hamstring Muscles / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D052580:Muscle Stretching Exercises / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology; D013710:Tendons / Q000502:physiology; D019415:Torque; D055815:Young Adult