Architectural and mechanical properties of the gastrocnemius muscle and Achilles tendon in relation to kendo training experience

This study aims to explore whether gender differences exist in the architectural and mechanical properties of the medial gastrocnemius–Achilles tendon unit (gMTU) in vivo. Thirty-six healthy male and female adults without training experience and regular exercise habits were recruited. The architectural and mechanical properties of the gMTU were measured via an ultrasonography system and MyotonPRO, respectively. Independent t-tests were utilized to quantify the gender difference in the architectural and mechanical properties of the gMTU. In terms of architectural properties, the medial gastrocnemius (MG)’s pennation angle and thickness were greater in males than in females, whereas no substantial gender difference was observed in the MG’s fascicle length; the males possessed Achilles tendons (ATs) with a longer length and a greater cross-sectional area than females. In terms of mechanical properties, the MG’s vertical stiffness was lower and the MG’s logarithmic decrement was greater in females than in males. Both genders had no remarkable difference in the AT’s vertical stiffness and logarithmic decrement. Gender differences of individuals without training experience and regular exercise habits exist in the architectural and mechanical properties of the gMTU in vivo. The MG’s force-producing capacities, ankle torque, mechanical efficiency and peak power were higher in males than in females. The load-resisting capacities of AT were greater and the MG strain was lesser in males than in females. These findings suggest that males have better physical fitness, speed and performance in power-based sports events than females from the perspective of morphology and biomechanics.

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Mechanical properties of tendon and aponeurosis of human gastrocnemius muscle in vivo

Journal of Applied Physiology ◽

10.1152/jappl.2001.90.5.1671 ◽

2001 ◽

Vol 90 (5) ◽

pp. 1671-1678 ◽

Cited By ~ 150

Author(s):

Tadashi Muramatsu ◽

Tetsuro Muraoka ◽

Daisuke Takeshita ◽

Yasuo Kawakami ◽

Yuichi Hirano ◽

...

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Gastrocnemius Muscle ◽

Plantar Flexion ◽

Medial Gastrocnemius ◽

Significant Difference ◽

Functional Implications ◽

Male Subjects ◽

Maximal Strain

Load-strain characteristics of tendinous tissues (Achilles tendon and aponeurosis) were determined in vivo for human medial gastrocnemius (MG) muscle. Seven male subjects exerted isometric plantar flexion torque while the elongation of tendinous tissues of MG was determined from the tendinous movements by using ultrasonography. The maximal strain of the Achilles tendon and aponeurosis, estimated separately from the elongation data, was 5.1 ± 1.1 and 5.9 ± 1.6%, respectively. There was no significant difference in strain between the Achilles tendon and aponeurosis. In addition, no significant difference in strain was observed between the proximal and distal regions of the aponeurosis. The results indicate that tendinous tissues of the MG are homogenously stretched along their lengths by muscle contraction, which has functional implications for the operation of the human MG muscle-tendon unit in vivo.

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Relationship Between Achilles Tendon Mechanical Properties and Gastrocnemius Muscle Function

Journal of Biomechanical Engineering ◽

10.1115/1.2895479 ◽

1993 ◽

Vol 115 (3) ◽

pp. 225-230 ◽

Cited By ~ 60

Author(s):

C. L. Trestik ◽

R. L. Lieber

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Computer Model ◽

Muscle Function ◽

Gastrocnemius Muscle ◽

Rana Pipiens ◽

Muscle Force ◽

Physiological Function ◽

Muscle Tension ◽

Tendon Lengthening

Strain was measured along the length of frog (Rana pipiens) gastrocnemius muscle-tendon units (MTU). Maximum muscle tension (P0) was measured, and the MTU was passively loaded to P0. Strain at P0 was measured at eight intervals along the tendon and aponeurosis and was approximately two percent for all regions except the aponeurosis region closest to the muscle fibers where it was about six percent. A computer model predicted sarcomere shortening of up to 0.5 μm due to tendon lengthening which demonstrates that tendons provide a more complex physiological function than simply transmitting muscle force to bones.

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Moderate-duration static stretch reduces active and passive plantar flexor moment but not Achilles tendon stiffness or active muscle length

Journal of Applied Physiology ◽

10.1152/japplphysiol.91476.2008 ◽

2009 ◽

Vol 106 (4) ◽

pp. 1249-1256 ◽

Cited By ~ 91

Author(s):

Anthony D. Kay ◽

Anthony J. Blazevich

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Muscle Stiffness ◽

Triceps Surae ◽

Medial Gastrocnemius ◽

Static Stretch ◽

Tendon Stiffness ◽

Neuromuscular Activity ◽

Time Motion ◽

The Impact

The effects of static stretch on muscle and tendon mechanical properties and muscle activation were studied in fifteen healthy human volunteers. Peak active and passive moment data were recorded during plantar flexion trials on an isokinetic dynamometer. Electromyography (EMG) monitoring of the triceps surae muscles, real-time motion analysis of the lower leg, and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction were simultaneously conducted. Subjects performed three 60-s static stretches before being retested 2 min and 30 min poststretch. There were three main findings in the present study. First, peak concentric moment was significantly reduced after stretch; 60% of the deficit recovered 30 min poststretch. This was accompanied by, and correlated with ( r = 0.81 ; P < 0.01) reductions in peak triceps surae EMG amplitude, which was fully recovered at 30 min poststretch. Second, Achilles tendon length was significantly shorter during the concentric contraction after stretch and at 30 min poststretch; however, no change in tendon stiffness was detected. Third, passive joint moment was significantly reduced after stretch, and this was accompanied by significant reductions in medial gastrocnemius passive muscle stiffness; both measures fully recovered by 30 min poststretch. These data indicate that the stretching protocol used in this study induced losses in concentric moment that were accompanied by, and related to, reductions in neuromuscular activity, but they were not associated with alterations in tendon stiffness or shorter muscle operating length. Reductions in passive moment were associated with reductions in muscle stiffness, whereas tendon mechanics were unaffected by the stretch. Importantly, the impact on mechanical properties and neuromuscular activity was minimal at 30 min poststretch.

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Comparison between dry needling and focused ultrasound on the mechanical properties of the rat Achilles tendon: A pilot study

Journal of Biomechanics ◽

10.1016/j.jbiomech.2021.110384 ◽

2021 ◽

Vol 120 ◽

pp. 110384

Author(s):

Sujata Khandare ◽

Molly Smallcomb ◽

Bailey Klein ◽

Colby Geary ◽

Julianna C. Simon ◽

...

Keyword(s):

Mechanical Properties ◽

Pilot Study ◽

Achilles Tendon ◽

Focused Ultrasound ◽

Dry Needling

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Sex Differences in the Morphological and Mechanical Properties of the Achilles Tendon

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18178974 ◽

2021 ◽

Vol 18 (17) ◽

pp. 8974

Author(s):

Xini Zhang ◽

Liqin Deng ◽

Songlin Xiao ◽

Lu Li ◽

Weijie Fu

Keyword(s):

Mechanical Properties ◽

Achilles Tendon ◽

Maximum Voluntary Contraction ◽

Voluntary Contraction ◽

Cross Sectional Area ◽

Morphological Properties ◽

Sectional Area ◽

Cross Sectional ◽

Force Peak ◽

Strain Stress

Background: Patients with Achilles tendon (AT) injuries are often engaged in sedentary work because of decreasing tendon vascularisation. Furthermore, men are more likely to be exposed to AT tendinosis or ruptures. These conditions are related to the morphological and mechanical properties of AT, but the mechanism remains unclear. This study aimed to investigate the effects of sex on the morphological and mechanical properties of the AT in inactive individuals. Methods: In total, 30 inactive healthy participants (15 male participants and 15 female participants) were recruited. The AT morphological properties (cross-sectional area, thickness, and length) were captured by using an ultrasound device. The AT force–elongation characteristics were determined during isometric plantarflexion with the ultrasonic videos. The AT stiffness was determined at 50%–100% maximum voluntary contraction force. The AT strain, stress, and hysteresis were calculated. Results: Male participants had 15% longer AT length, 31% larger AT cross-sectional area and 21% thicker AT than female participants (p < 0.05). The plantarflexion torque, peak AT force, peak AT stress, and AT stiffness were significantly greater in male participants than in female participants (p < 0.05). However, no significant sex-specific differences were observed in peak AT strain and hysteresis (p > 0.05). Conclusions: In physically inactive adults, the morphological properties of AT were superior in men but were exposed to higher stress conditions. Moreover, no significant sex-specific differences were observed in peak AT strain and hysteresis, indicating that the AT of males did not store and return elastic energy more efficiently than that of females. Thus, the mechanical properties of the AT should be maintained and/or improved through physical exercise.

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Paraffin therapy induces a decrease in the passive stiffness of gastrocnemius muscle belly and Achilles tendon

Medicine ◽

10.1097/md.0000000000019519 ◽

2020 ◽

Vol 99 (12) ◽

pp. e19519

Author(s):

Ya Peng Li ◽

Ya Nan Feng ◽

Chun Long Liu ◽

Zhi Jie Zhang

Keyword(s):

Achilles Tendon ◽

Gastrocnemius Muscle ◽

Passive Stiffness ◽

Muscle Belly

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Tendon Morphology and Mechanical Properties Are Associated With the Recovery of Symptoms and Function in Patients With Achilles Tendinopathy

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967120917271 ◽

2020 ◽

Vol 8 (4) ◽

pp. 232596712091727

Author(s):

Patrick Corrigan ◽

Daniel H. Cortes ◽

Ryan T. Pohlig ◽

Karin Grävare Silbernagel

Keyword(s):

Mechanical Properties ◽

Shear Modulus ◽

Achilles Tendon ◽

Achilles Tendinopathy ◽

Calf Muscle ◽

Initial Assessment ◽

Muscle Endurance ◽

Patient Reported ◽

Morphology And Mechanical Properties

Background: Achilles tendinopathy is a debilitating overuse injury characterized by pain, altered Achilles tendon structure, and impaired functional performance. Evaluating tendon structure as part of the physical examination may help establish a well-defined prognosis. However, the usefulness of measuring tendon structure for developing a prognosis has been questioned since structural abnormalities can exist without symptoms. Purpose: To determine whether initial measures of tendon morphology and mechanical properties were associated with patient-reported symptoms and calf muscle endurance at baseline, 6-month follow-up, and 1-year follow-up by prospectively following a cohort of individuals with Achilles tendinopathy. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 59 participants with midportion or insertional Achilles tendinopathy completed an initial assessment and follow-up assessments at 6 months and 1 year. At the initial assessment, patient-reported symptoms, calf muscle endurance, and Achilles tendon thickening were evaluated, and Achilles tendon mechanical properties were estimated. At the 6-month and 1-year follow-up assessments, patient-reported symptoms and calf muscle endurance were reevaluated. Results: Greater Achilles tendon thickening at the initial assessment was consistently associated with worse patient-reported symptoms and calf muscle endurance at each assessment. Changes in symptoms over the year were moderated by the initial shear modulus of the tendon, with a lower shear modulus associated with less improvement in symptoms. Lower viscosity at the initial assessment was also associated with worse calf muscle endurance at each assessment. Conclusion: Measures of tendon morphology and mechanical properties appear to be associated with patient-reported symptoms and calf muscle function for patients with Achilles tendinopathy.

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