Effects of static stretching duration on muscle stiffness and blood flow in the rectus femoris in adolescents

Abstract

Aims: To compare the effects of 2 and 5 min of passive static stretching (SS) on stiffness and blood flow in the rectus femoris in adolescent athletes using shear wave elastography (SWE) and superb microvascular imaging (SMI).Material and methods: This prospective study included 20 male athletes with median age of 14.5 (12.5–16.5) years. The subjects were divided into two groups based on the SS duration as follows: 2 min (n=10) and 5 min (n=10). At rest and after 2 and 5 min of SS, stiffness and blood flow values were compared in the rectus femoris for each group. Inter-operator reliability was also analysed.Results: There was no significant difference between resting and 2 min of SS in terms of stiffness. The stiffness values decreased significantly from resting to 5 min of SS. The blood flow increased significantly from resting to 2 and 5 min of SS. Inter-operator reliability was moderate to perfect for SWE and SMI measurements (ICC: 0.52–0.83).Conclusions: SWE and SMI can be used to acquire reliable quantitative data about muscle stiffness and blood flow in adolescents. While stiffness parameters significantly decreased from resting after only 5 min, blood flow significantly increased both after 2 and 5 min. For physical rehabilitation protocols, 5 min of SS may be chosen to reduce stiffness. For competitions, 2 min of SS may be sufficient for warm-up exercise because it increases the blood flow optimally. Five min of SS may be preferred for the cool-down exercise to enhance recovery.

The Comparison of Different Stretching Intensities on the Range of Motion and Muscle Stiffness of the Quadriceps Muscles

“…Previous studies showed that muscle stiffness in the plantar flexors (Nakamura et al, 2014(Nakamura et al, , 2017(Nakamura et al, , 2019, hamstrings (Umegaki et al, 2015;Miyamoto et al, 2017), and quadriceps (Caliskan et al, 2019) were decreased immediately after a static stretching intervention. Interestingly, while recent studies focused on the stretching intensity, Kataura et al (2017) investigated on the effect of three different stretching intensities on the hamstring muscle-tendon unit passive stiffness, with results showing the effectiveness of a high-intensity static stretching intervention in increasing range of motion (ROM) and decreasing passive stiffness of the muscle-tendon unit (Kataura et al, 2017).…”

Greater Muscle Stiffness during Contraction at Menstruation as Measured by Shear-Wave Elastography

“…In comparison with other imaging modalities, such as magnetic resonance imaging, SWE is cheaper, faster, more reliable, and more valid in measuring the mechanical properties of tissues (Andonian et al 2016;Heales et al 2018). SWE calculates the tissue stiffness using Young's modulus by examining the propagation velocity of the induced shear waves from a region of interest (ROI) in deep muscles, superficial muscles, and any other soft tissues (Chen et al 2017;Feng et al 2018;Caliskan et al 2019;Siracusa et al 2019).…”

Muscle Ultrasonographic Elastography in Children: Review of the Current Knowledge and Application

“…Most of these studies assessed GCM changes as the effects of ankle joint dorsiflexion (DF), PF, and neutral position. Even though clear methodological differences (regarding the exact ankle angle measured, knee flexion, the study protocol used, and the tools used to ensure planned feet position) were present, the results were coherent; passive stiffness increased as a result of increased DF angle [14,15,25]. In a study of SWE of the anterior tibialis (AT) muscle and GCM in hemiplegic patients, Lee et al confirmed that ankle angle had significant effects on both muscles.…”