scholarly journals Relationships among Electromyogram, Displacement and Velocity of the Center of Pressure, and Muscle Stiffness of the Medial Gastrocnemius Muscle during Quiet Standing

2020 ◽  
Vol 9 (0) ◽  
pp. 138-145 ◽  
Author(s):  
Takanori Uchiyama ◽  
Gai Kondo
Keyword(s):  
Gastrocnemius Muscle ◽  
Center Of Pressure ◽  
Muscle Stiffness ◽  
Medial Gastrocnemius ◽  
Quiet Standing ◽  
Medial Gastrocnemius Muscle

scholarly journals The Associations between Rapid Strength Development and Muscle Stiffness in Older Population

Healthcare ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 80
Author(s):  
Masatoshi Nakamura ◽  
Ryosuke Kiyono ◽  
Shigeru Sato ◽  
Kaoru Yahata ◽  
Taizan Fukaya ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Gastrocnemius Muscle ◽  
Shear Wave Elastography ◽  
Muscle Stiffness ◽  
Rate Of Force Development ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Force Development ◽  
Shear Elastic Modulus ◽  
Medial Gastrocnemius Muscle

Background: Previous studies suggest that the capacity for rapid force production of ankle plantar flexors is essential for the prevention of falls in the elderly. In healthy young adults, there were significant associations between rate of force development and muscle stiffness measured by shear wave elastography. However, there has been no study investigating the association of rate of force development with shear elastic modulus in older adults. Methods: The muscle strength and shear elastic modulus of the medial gastrocnemius muscle in both legs were measured in 17 elderly men and 10 elderly women (mean ± SD; 70.7 ± 4.1 years; 160.6 ± 8.0 cm; 58.7 ± 9.5 kg). We investigated the rate of force development of plantar flexors and shear elastic modulus of medial gastrocnemius muscle using by shear wave elastography. Results: Our results showed that there were no significant associations between normalized rate of force development and shear elastic modulus of medial gastrocnemius muscle. Conclusion: This suggests that the capacity of rapid force production could be related not to muscle stiffness of the medial gastrocnemius muscle, but to neuromuscular function in older individuals.

Active muscle stiffness in the human medial gastrocnemius muscle in vivo

2014 ◽  
Vol 117 (9) ◽  
pp. 1020-1026 ◽  
Author(s):  
Keitaro Kubo
Keyword(s):  
Gastrocnemius Muscle ◽  
Muscle Stiffness ◽  
Medial Gastrocnemius ◽  
Plantar Flexors ◽  
Active Muscle ◽  
Tendon Stiffness ◽  
Series Elastic Component ◽  
In Series ◽  
Medial Gastrocnemius Muscle

The aims of this study were to 1) directly assess active muscle stiffness according to actual length changes in muscle fibers (fascicles) during short range stretching; and 2) compare actual measured active muscle and tendon stiffness using ultrasonography with the stiffness of active (i.e., muscle) and passive (i.e., tendon) parts in series elastic component of plantar flexors using the alpha method. Twenty-four healthy men volunteered for this study. Active muscle stiffness in the medial gastrocnemius muscle was calculated according to changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions [10, 30, 50, 70, and 90% maximal voluntary contractions (MVC)]. Using the variables measured during this fast stretch experiment, the stiffness of active (i.e., muscle) and passive (i.e., tendon) parts in plantar flexors was assessed using alpha method. Tendon stiffness was determined during isometric plantar flexion by ultrasonography. Active muscle stiffness increased with the exerted torque levels. At 30, 50, 70, and 90% MVC, there were no significant correlations between muscle stiffness using ultrasonography and stiffness of active part (i.e., muscle) by alpha method, although this relationship at 10% MVC was significant ( r = 0.552, P = 0.005). In addition, no correlation was noted in tendon stiffness between the two different methods ( r = 0.226, P = 0.209). The present study demonstrated that ultrasonography could quantified active muscle stiffness in vivo. Furthermore, active muscle stiffness and tendon stiffness using ultrasonography were not related to active (i.e., muscle) or passive (i.e., tendon) stiffness in series elastic component of plantar flexors by alpha method.

scholarly journals Training and Detraining Effects Following a Static Stretching Program on Medial Gastrocnemius Passive Properties

2021 ◽  
Vol 12 ◽  
Author(s):  
Masatoshi Nakamura ◽  
Kaoru Yahata ◽  
Shigeru Sato ◽  
Ryosuke Kiyono ◽  
Riku Yoshida ◽  
...  
Keyword(s):  
Intervention Program ◽  
Gastrocnemius Muscle ◽  
High Volume ◽  
Muscle Stiffness ◽  
Medial Gastrocnemius ◽  
Exercise Session ◽  
Static Stretching ◽  
Passive Torque ◽  
Medial Gastrocnemius Muscle

A stretching intervention program is performed to maintain and improve range of motion (ROM) in sports and rehabilitation settings. However, there is no consensus on the effects of stretching programs on muscle stiffness, likely due to short stretching durations used in each session. Therefore, a longer stretching exercise session may be required to decrease muscle stiffness in the long-term. Moreover, until now, the retention effect (detraining) of such an intervention program is not clear yet. The purpose of this study was to investigate the training (5-week) and detraining effects (5-week) of a high-volume stretching intervention on ankle dorsiflexion ROM (DF ROM) and medial gastrocnemius muscle stiffness. Fifteen males participated in this study and the plantarflexors of the dominant limb were evaluated. Static stretching intervention was performed using a stretching board for 1,800 s at 2 days per week for 5 weeks. DF ROM was assessed, and muscle stiffness was calculated from passive torque and muscle elongation during passive dorsiflexion test. The results showed significant changes in DF ROM and muscle stiffness after the stretching intervention program, but the values returned to baseline after the detraining period. Our results indicate that high-volume stretching intervention (3,600 s per week) may be beneficial for DF ROM and muscle stiffness, but the training effects are dismissed after a detraining period with the same duration of the intervention.

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