Acute Effects of Static Stretching on Muscle Hardness of the Medial Gastrocnemius Muscle Belly in Humans: An Ultrasonic Shear-Wave Elastography Study

Context: In clinical and sports settings, static stretching (SS) is usually performed to increase range of motion (ROM) and decrease passive muscle stiffness. Recently, the shear elastic modulus was measured by ultrasonic shear wave elastography as an index of muscle stiffness. Previous studies reported that the shear elastic modulus measured by ultrasound shear wave elastography decreased after SS, and the effects of SS on shear elastic modulus were likely affected by rest duration between sets of SS. Objective: To investigate the acute effects of SS with different rest durations on ROM and shear elastic modulus of gastrocnemius and to clarify whether the rest duration between sets of SS decreases the shear elastic modulus. Design: A randomized, repeated-measures experimental design. Setting: University laboratory. Participants: Sixteen healthy males volunteered to participate in the study (age 21.3 [0.8] y; height 171.8 [5.1] cm; weight 63.1 [4.5] kg). Main Outcome Measures: Each participant underwent 3 different rest interval durations during SS (ie, long rest duration: 90 s; normal rest duration: 30 s; and short rest duration: 10 s). This SS technique was repeated 10 times, thus lasting a total of 300 seconds with different rest durations in each protocol. The dorsiflexion ROM and shear elastic modulus were measured before and after SS. Results: Our results revealed that dorsiflexion ROM and shear elastic modulus were changed after 300-second SS; however, no effects of the rest duration between sets of SS were observed. Conclusions: In terms of decreasing the shear elastic modulus, clinicians and coaches should not focus on the rest duration when SS intervention is performed.

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Complete Adipose Replacement of Bilateral Medial Gastrocnemius Muscle - A Cadaveric Case Report

Academia Anatomica International ◽

10.21276/aanat.2020.6.1.14 ◽

2020 ◽

Vol 6 (1) ◽

pp. 62-64

Author(s):

Charles Nichols ◽

Elizabeth Liu ◽

Howe Liu

Keyword(s):

Adipose Tissue ◽

Gastrocnemius Muscle ◽

Medial Gastrocnemius ◽

Advanced Dementia ◽

Muscle Belly ◽

Intermuscular Adipose Tissue ◽

Left And Right ◽

Gastrocnemius Muscles ◽

Caucasian Female ◽

Medial Gastrocnemius Muscle

Sarcopenia and infiltration of intermuscular adipose tissue are often seen in older adults due to aging process, but a muscle is completely replaced by adipose tissue is rarely reported. In this cadaveric case, we describe an observation of bilateral symmetric adipose replacement of the medial gastrocnemius muscles (GM) on both left and right leg in an 82-year old Caucasian female, whose cause of death was advanced dementia. The white adipose tissue replaced the entire medial GM muscle belly with pennate-like arrangement, indicating adipose tissue infiltration very likely into the original muscle cells. Where and how these adipose tissues come from are discussed.

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

Healthcare ◽

10.3390/healthcare9010080 ◽

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.

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Characterization of passive elastic properties of the human medial gastrocnemius muscle belly using supersonic shear imaging

Journal of Biomechanics ◽

10.1016/j.jbiomech.2012.01.009 ◽

2012 ◽

Vol 45 (6) ◽

pp. 978-984 ◽

Cited By ~ 152

Author(s):

Olivier Maïsetti ◽

François Hug ◽

Killian Bouillard ◽

Antoine Nordez

Keyword(s):

Elastic Properties ◽

Gastrocnemius Muscle ◽

Medial Gastrocnemius ◽

Muscle Belly ◽

Supersonic Shear Imaging ◽

Medial Gastrocnemius Muscle

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Modelling the pressure and force equilibrium in unipennate muscles with in-line tendons

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.1993.0162 ◽

1993 ◽

Vol 342 (1302) ◽

pp. 321-333 ◽

Cited By ~ 28

Keyword(s):

Negative Curvature ◽

Gastrocnemius Muscle ◽

Mechanical Stability ◽

Positive Curvature ◽

Medial Gastrocnemius ◽

Outer Side ◽

Muscle Fibres ◽

Muscle Belly ◽

Medial Gastrocnemius Muscle ◽

Force Equilibrium

Several of the models proposed in the literature of unipennate muscles, which have two tendinous sheets and in-line tendons, cannot meet the criterion of mechanical stability. Based on the theory of Van Leeuwen & Spoor ( Phil. Trans. R. Soc. Lond. B 336, 275-292 (1992)), we discuss how mechanically stable solutions for (planar) unipennate architectures could be obtained. A mathematical model is proposed in which the muscle architecture is generated numerically using the principles of mechanical stability and assuming that all muscle fibres shorten by the same relative amount. The tendinous sheets are attached tangentially to their respective tendons, as predicted from their low bending stiffness. The curvature, however, is discontinuous at the junction because of the sudden absence of muscle fibres from aponeurosis to tendon. In two of the muscle shapes generated, the sheets adjacent to the tendon show a region of negative curvature connected to a region of positive curvature. A sheet with a concave outer side is defined to have a negative curvature. In another example, two negative curvature regions are present with a positive region in-between. We show also a generated shape with a negative curvature of the sheets over their whole length. A good resemblance was found between the unipennate medial gastrocnemius muscle of the cat and a simulated architecture. The pressure distribution has also been calculated. With all muscle fibres exerting the same tensile stress of 200 kPa, a high pressure region is present in the centre of the muscle belly, half-way along its length. The highest pressures are predicted for muscles with long tendinous sheets, large attachment angles, and strongly curved fibres. Maximum pressures (2.40, 9.54, 10.47, and 7.57 kPa for the four discussed examples, and 15.05 kPa for the simulated gastrocnemius muscle) were at the lower side of the range as predicted previously for bipennate muscles and the unipennate medial gastrocnemius muscle of man (Van Leeuwen & Spoor 1992).

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Shear elastic modulus is a reproducible index reflecting the passive mechanical properties of medial gastrocnemius muscle belly

Acta Radiologica Open ◽

10.1177/2058460115604009 ◽

2016 ◽

Vol 5 (4) ◽

pp. 205846011560400 ◽

Cited By ~ 8

Author(s):

Masatoshi Nakamura ◽

Tome Ikezoe ◽

Hiroki Umegaki ◽

Takuya Kobayashi ◽

Satoru Nishisita ◽

...

Keyword(s):

Mechanical Properties ◽

Elastic Modulus ◽

Gastrocnemius Muscle ◽

Medial Gastrocnemius ◽

Muscle Belly ◽

Shear Elastic Modulus ◽

Medial Gastrocnemius Muscle

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

Frontiers in Physiology ◽

10.3389/fphys.2021.656579 ◽

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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