Article
Engineering, Geological
Kazem Fakharian, Ali Ahmad
Summary: The study shows that adding granulated rubber decreases shear modulus and increases damping ratio of granulated rubber-sand mixtures, while also helping to reduce the degradation rate of shear modulus. Anisotropic consolidation has little effects on the variations of shear modulus and damping ratio of sand-rubber mixtures.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Sport Sciences
Kosuke Takeuchi, Masahiro Takemura, Masatoshi Nakamura, Fumiko Tsukuda, Shumpei Miyakawa
Summary: The study found that an active warm-up with aerobic exercise can increase flexibility and strength of the calf muscles, while other warm-up methods did not show significant changes.
JOURNAL OF STRENGTH AND CONDITIONING RESEARCH
(2021)
Article
Engineering, Civil
Ahmed Alnuaim, Naif Alsanabani, Abdulhafiz Alshenawy
Summary: Studies show that sabkha soils exhibit ductile behavior with high cohesion and friction angle. The shear moduli decrease with shear strain for different cyclic stress ratios, while the damping ratio depends on the level of the cyclic stress ratio.
INTERNATIONAL JOURNAL OF CIVIL ENGINEERING
(2021)
Article
Engineering, Geological
Beibei Yang, Mingming He, Zhiqiang Zhang, Jiwei Zhu, Yunsheng Chen
Summary: The dynamic shear modulus and damping ratio of rocks were studied under different confining pressures using a multistage cyclic triaxial compression test. The relationship between the dynamic shear modulus, damping ratio, and cyclic shear strain under different confining pressure conditions was analyzed. Empirical formulas were established for estimating the dynamic shear modulus and damping ratio. The results showed that the damping ratio of red sandstone and granite first decreased and then increased with increasing shear strain under variable amplitude conditions. The damping ratio of red sandstone and granite was less affected by the confining pressure when the shear strain was constant. The dynamic shear modulus under different confining pressures increased as the shear strain increased under the same amplitude conditions.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Physiology
Taija Finni, Annamaria Peter, Ra'ad Khair, Neil J. Cronin
Summary: The tracking point location has an effect on the displacement of MG MTJ during isometric plantar flexion contractions. Tracking a point on the aponeurosis consistently exaggerates estimates of tendon displacement, and this effect is dependent on the intensity of the contraction.
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
(2022)
Review
Chemistry, Multidisciplinary
Ruchi Shah, Marina W. Samuel, Jongsang Son
Summary: This review provides an overview of the recent research on the acute and chronic effects of static stretching on joint behaviors and neuromuscular responses. The findings suggest that static stretching can increase joint range of motion and reduce muscle and tendon properties.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Geological
Binghui Song, Angelos Tsinaris, Anastasios Anastasiadis, Kyriazis Pitilakis, Wenwu Chen
Summary: This study examines the small to medium strain dynamic properties of intact and recompacted loess in Lanzhou. The influence of soil structure on the dynamic properties is analyzed, and a normalized correlation is found between G/G0 and gamma/gamma 0.7, which is practically identical for both types of loess.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Marine
Weijia Ma, You Qin, Fei Gao, Qi Wu
Summary: This study investigates the effects of several consolidation state parameters on the shear modulus of saturated coral sand through a multi-stage strain-controlled undrained cyclic shear test. The results show that the shear modulus increases with increasing effective mean principal stress and consolidation ratio, but decreases with increasing consolidation direction angle and coefficient of intermediate principal stress. A new index 14G0 is proposed to modify the prediction model of shear modulus. It is also found that there is an identical relationship between normalized shear modulus and normalized shear strain for various consolidation state parameters, which can be described by the Davidenkov model. By using the prediction model proposed in this study, an excellent prediction of shear modulus can be obtained with a deviation within +/- 10%.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Review
Acoustics
Gianluca Rossetto, Nicola Francesco Lopomo, Summaiva Zareen Shaikh
Summary: This study aimed to assess the effectiveness of ultrasonography (US) and ultrasound elastography (UE) in evaluating longitudinal sliding and stiffness of nerves. By analyzing 1112 publications from 2010 to 2021, the study found that US and UE are effective methods for assessing the mentioned parameters in lower extremity nerves. The study also identified differences in shear wave velocity (SWV) and shear modulus (SM) between control participants and those with leg pain or diabetic peripheral neuropathy (DPN).
ULTRASOUND IN MEDICINE AND BIOLOGY
(2023)
Article
Forestry
Zheng Wang, Xiaoyu Gu, Sarah Mohrmann, Zhaoyu Shen, Yujie Huang, Yuhao Zhou
Summary: This study used the static analysis method of ANSYS 19 to analyze the stress and strain of longitudinal, radial, and tangential beam specimens of spruce, Scots pine, and beech. The effects of wood grain on the surface of the specimen and its stress properties on the transverse and longitudinal strain were experimentally studied. The results showed that the four-point bending beam method is suitable for testing the elastic modulus, Poisson's ratio, and shear modulus of wood.
EUROPEAN JOURNAL OF WOOD AND WOOD PRODUCTS
(2023)
Article
Chemistry, Analytical
Steve Hunter, Julian Werth, Darren James, Yiannis Lambrianides, Kenton Smith, Kiros Karamanidis, Gaspar Epro
Summary: This study presents a time-efficient ultrasound method for assessing Achilles tendon mechanical properties. The method was validated through comparisons with manual frame by frame tracking, and showed similar results in measuring maximal tendon force, elongation, strain, and stiffness index. Additionally, the method was able to detect significant differences in tendon force and stiffness index between different groups of individuals. This analysis has the potential to accurately monitor changes in the mechanical properties of the Achilles tendon due to aging and altered loading.
Review
Geriatrics & Gerontology
Masatoshi Nakamura, Kosuke Takeuchi, Taizan Fukaya, Gakuto Nakao, Andreas Konrad, Takamasa Mizuno
Summary: Static stretching can decrease the passive stiffness of the muscle-tendon unit (MTU) and/or muscles in older adults. The effects of static stretching on stiffness are comparable between older and young adults.
ARCHIVES OF GERONTOLOGY AND GERIATRICS
(2024)
Article
Engineering, Civil
Johann Facciorusso
Summary: Measurement of soil properties under cyclic and dynamic loading conditions is crucial in solving geotechnical earthquake engineering problems. Dynamic properties of soils, expressed in shear modulus (G) and damping ratio (D), are typically obtained from laboratory tests at different strain levels. Empirical relationships between dynamic parameters and routine geotechnical test measurements are commonly used, highlighting the importance of a large and reliable archive of testing results for geotechnical earthquake engineers and researchers.
EARTHQUAKE SPECTRA
(2021)
Article
Engineering, Mechanical
Liu Jin, Binlin Zhang, Fengjuan Chen, Wenxuan Yu, Yushuang Lei, Liyue Miao, Xiuli Du
Summary: A two-dimensional meso-scale numerical model is proposed to accurately simulate the dynamic mechanical behavior of RC shear walls subjected to dynamic loads in this paper. The impacts of shear span ratio and strain rate on the dynamic mechanical properties and size effect law of the RC shear walls are investigated. Based on the results, a dynamic size effect formula of the RC shear wall is proposed and validated by comparing both simulation and experimental results.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Medicine, General & Internal
Claudia Roemer, Enrico Zessin, Julia Czupajllo, Thomas Fischer, Bernd Wolfarth, Markus Herbert Lerchbaumer
Summary: This study investigates the impacts of various physical parameters and different sports on patellar tendon stiffness in professional athletes using shear wave elastography (SWE). The results show no significant differences in patellar tendon stiffness according to gender, age, body mass index (BMI) and type of sport. Oral contraceptive (OC) intake may have some impact on patellar tendon stiffness in female athletes, but not significantly.
Article
Sport Sciences
Kazuki Kasahara, Andreas Konrad, Riku Yoshida, Yuta Murakami, Shigeru Sato, Ryoma Koizumi, David G. Behm, Masatoshi Nakamura, Pain Pressure
Summary: This study aimed to compare the combined effects of static stretching (SS) and dynamic stretching (DS) with foam rolling (FR) on the function and properties of the knee extensors, and the intervention order effects. The results showed that all the combinations of SS or DS and FR effectively decreased tissue stiffness and increased range of motion, without decreasing muscle strength and jump performance.
Review
Physiology
Andreas Konrad, Masatoshi Nakamura, Konstantin Warneke, Olyvia Donti, Anna Gabriel
Summary: A single bout of foam rolling can increase joint range of motion without affecting muscle performance. Long-term foam rolling training also increases joint range of motion without impacting muscle performance. However, the effects of foam rolling on the contralateral limb are not well-known. Potential mechanisms for increased range of motion include reduced perception of pain. Only limited evidence suggests that foam rolling on one limb increases range of motion in the contralateral limb. Muscle performance in the contralateral limb is generally unaffected after foam rolling. Only one study reported impaired rate of force development in the contralateral limb. Limited studies on long-term foam rolling training show moderate improvements in performance. Interpretation of the findings should be cautious.
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
(2023)
Article
Physiology
Riku Yoshida, Kazuki Kasahara, Yuta Murakami, Shigeru Sato, Kazunori Nosaka, Masatoshi Nakamura
Summary: This study compared the fatigue profiles of the biceps brachii muscle during repetitive maximal concentric and eccentric contractions, and found that the muscle had greater fatigue resistance during eccentric contractions compared to concentric contractions.
EUROPEAN JOURNAL OF APPLIED PHYSIOLOGY
(2023)
Article
Sport Sciences
Masatoshi Nakamura, Tatsuro Ishikawa, Shigeru Sato, Ryosuke Kiyono, Riku Yoshida, Katsuyuki Morishita, Andreas Konrad
Summary: This study aimed to investigate the time-course changes in range of motion, stretch sensation, shear elastic modulus, and muscle temperature during hot pack application. The results showed that hot pack application for >5 minutes significantly increased range of motion, stretch tolerance, and muscle temperature, while significantly decreased shear elastic modulus.
JOURNAL OF SPORTS SCIENCE AND MEDICINE
(2023)
Article
Sport Sciences
Konstantin Warneke, Jose Carlos Aragao-Santos, Shahab Alizadeh, Mahdi Bahrami, Saman Hadjizadeh Anvar, Andreas Konrad, David G. Behm
Summary: In the past decade, foam rolling has been frequently reported to acutely increase range of motion (ROM). However, it remains unclear whether these ROM increases are solely attributed to foam rolling or simply a result of warm-up effects. This study found that both foam rolling and sham rolling (imitating the foam rolling movement without pressure) induced significant increases in passive ROM and non-local ROM, but there was no significant difference between the two conditions. This suggests that potential acute increases in ROM cannot be exclusively attributed to foam rolling, and warm-up effects may play a role.
JOURNAL OF SPORTS SCIENCE AND MEDICINE
(2023)
Article
Sport Sciences
Kazuki Kasahara, Andreas Konrad, Riku Yoshida, Yuta Murakami, Shigeru Sato, Ryoma Koizumi, David G. Behm, Masatoshi Nakamura
Summary: This study compares and examines the effects of short-term static stretching (SS), foam rolling (FR), and SS+FR as warm-ups for knee extensors. The results show that short-term SS, FR, and SS+FR are effective in increasing range of motion (ROM), improving pain pressure threshold (PPT), and reducing tissue hardness. However, SS interventions longer than 30 seconds decrease muscle strength, while short-term FR interventions are recommended to increase ROM while maintaining muscle strength.
JOURNAL OF SPORTS SCIENCE AND MEDICINE
(2023)
Review
Sport Sciences
David G. Behm, Shahab Alizadeh, Abdolhamid Daneshjoo, Andreas Konrad
Summary: The use of dynamic stretching as a replacement for static stretching in warm-up is widespread, but there is a lack of literature on the effects of dynamic stretching on injury incidence. Studies have shown mixed results, with some demonstrating positive effects on injury incidence while others showing no significant difference. The effects of dynamic stretching on range of motion, strength, balance, proprioception, muscle morphology, and psycho-physiological responses are also unclear. More extensive studies are needed in this area to provide clearer conclusions.
Article
Health Care Sciences & Services
Andreas Konrad, Kazuki Kasahara, Riku Yoshida, Yuta Murakami, Ryoma Koizumi, Masatoshi Nakamura
Summary: This study aimed to investigate the repeated application of PPT tests in different muscles. The results showed a significant increase in PPT in the elbow flexors and knee extensors, starting from the eighth and ninth assessments, respectively. However, there was no significant change in the ankle plantar flexor muscles. Based on these findings, it is recommended to perform between two and seven PPT assessments to avoid overestimation.
Review
Geriatrics & Gerontology
Masatoshi Nakamura, Kosuke Takeuchi, Taizan Fukaya, Gakuto Nakao, Andreas Konrad, Takamasa Mizuno
Summary: Static stretching can decrease the passive stiffness of the muscle-tendon unit (MTU) and/or muscles in older adults. The effects of static stretching on stiffness are comparable between older and young adults.
ARCHIVES OF GERONTOLOGY AND GERIATRICS
(2024)
Review
Sport Sciences
Kosuke Takeuchi, Masatoshi Nakamura, Taizan Fukaya, Andreas Konrad, Takamasa Mizuno
Summary: Static stretching can increase joint range of motion and potentially decrease muscle-tendon unit stiffness (MTS), but the effects of acute and long-term static stretching on MTS are not well understood. This meta-analysis aimed to investigate the effects of acute and long-term static stretching training on MTS in young healthy participants. The results showed a moderate decrease in MTS after acute static stretching, but no significant change overall.
JOURNAL OF SPORTS SCIENCE AND MEDICINE
(2023)
Article
Sport Sciences
Hayley R. R. Gardner, Andreas Konrad, Shahab Alizadeh, Andrew Graham, David G. G. Behm
Summary: This study investigated the perception of time during different intensity isometric contractions and found that maximal contractions resulted in underestimation of time at 5, 20, and 30 seconds, while submaximal contractions led to underestimation at 30 seconds. Females showed a greater underestimation of 5-second intervals during the interventions. These findings suggest that time is significantly underestimated during moderate to vigorous intensity exercise.
FRONTIERS IN SPORTS AND ACTIVE LIVING
(2023)
Article
Sport Sciences
Mohammad Alimoradi, Mansour Sahebozamani, Elham Hosseini, Andreas Konrad, Sajad Noorian
Summary: The purpose of this study was to investigate the effects of 4 weeks of soleus stretching on ankle flexibility and dynamic balance, as well as selected monitoring and performance tests in soccer. The results showed that adding soleus stretching into regular protocols can provide benefits for female soccer players in terms of performance parameters.
Review
Sport Sciences
Ioli Panidi, Olyvia Donti, Andreas Konrad, Petros C. Dinas, Gerasimos Terzis, Athanasios Mouratidis, Vasiliki Gaspari, Anastasia Donti, Gregory C. Bogdanis
Summary: Static stretching training increases fascicle length at rest and during stretching in healthy participants. High stretching volumes and intensities induce longitudinal fascicle growth, while high stretching intensities result in increased muscle thickness.
SPORTS MEDICINE-OPEN
(2023)