title: Acute effects of static stretching on muscle hardness of the medial gastrocnemius muscle belly in humans: an ultrasonic shear-wave elastography study.
abstract: This study investigated the acute effects of static stretching (SS) on shear elastic modulus as an index of muscle hardness and muscle stiffness and the relationship between change in shear elastic modulus and change in muscle stiffness after SS. The patients were 17 healthy young males. Muscle stiffness was measured during passive ankle dorsiflexion using a dynamometer and ultrasonography before (pre) and immediately after (post) 2 min of SS. In addition, shear elastic modulus was measured by a new ultrasound technique called ultrasonic shear wave elastography. The post-SS values for muscle stiffness and shear elastic modulus were significantly lower than the pre-SS values. In addition, Spearman's rank correlation coefficient indicated a significant correlation between rate of change in shear elastic modulus and rate of change in muscle stiffness. These results suggest that SS is an effective method for decreasing shear elastic modulus as well as muscle stiffness and that shear elastic modulus measurement using the shear wave elastography technique is useful in determining the effects of SS.
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan. Electronic address: Nakamura.masatoshi.55x@st.kyoto-u.ac.jp.
authors: Masatoshi
authors: M
authors: Nakamura
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Tome
authors: T
authors: Ikezoe
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Takuya
authors: T
authors: Kobayashi
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Hiroki
authors: H
authors: Umegaki
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Yohei
authors: Y
authors: Takeno
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Satoru
authors: S
authors: Nishishita
authors: Human Health Sciences, Graduate School of Medicine, Kyoto University, Japan.
authors: Noriaki
authors: N
authors: Ichihashi
mesh_terms: D000328:Adult; D000843:Ankle Joint / Q000000981:diagnostic imaging; D055119:Elastic Modulus; D054459:Elasticity Imaging Techniques / Q000379:methods*; D004576:Electromyography / Q000379:methods; D006244:Hardness; D006801:Humans; D008297:Male; D052580:Muscle Stretching Exercises / Q000379:methods*; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D012016:Reference Values; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Muscle stiffness; Shear elastic modulus; Shear wave elastography; Static stretching