scholarly journals An Identical Twin Study on Human Achilles Tendon Adaptation: Regular Recreational Exercise at Comparatively Low Intensities Can Increase Tendon Stiffness

2022 ◽  
Vol 12 ◽  
Author(s):  
Freddy Sichting ◽  
Nicolai C. Kram ◽  
Kirsten Legerlotz
Keyword(s):  
Mechanical Properties ◽  
Genetic Variation ◽  
Achilles Tendon ◽  
Injury Risk ◽  
Identical Twin ◽  
Cross Sectional ◽  
Tendon Stiffness ◽  
Recreational Exercise ◽  
Tendon Adaptation ◽  
The Impact

Achilles tendon adaptation is a key aspect of exercise performance and injury risk prevention. However, much debate exists about the adaptation of the Achilles tendon in response to exercise activities. Most published research is currently limited to elite athletes and selected exercise activities. Also, existing studies on tendon adaptation do not control for genetic variation. Our explorative cross-sectional study investigated the effects of regular recreational exercise activities on Achilles tendon mechanical properties in 40 identical twin pairs. Using a handheld oscillation device to determine Achilles tendon mechanical properties, we found that the Achilles tendon appears to adapt to regular recreational exercise at comparatively low intensities by increasing its stiffness. Active twins showed a 28% greater Achilles tendon stiffness than their inactive twin (p < 0.05). Further, our research extends existing ideas on sport-specific adaptation by showing that tendon stiffness seemed to respond more to exercise activities that included an aerial phase such as running and jumping. Interestingly, the comparison of twin pairs revealed a high variation of Achilles tendon stiffness (305.4–889.8 N/m), and tendon adaptation was only revealed when we controlled for genetic variance. Those results offer new insights into the impact of genetic variation on individual Achilles tendon stiffness, which should be addressed more closely in future studies.

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

2009 ◽  
Vol 106 (4) ◽  
pp. 1249-1256 ◽  
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.

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

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.

scholarly journals Cannabis use and work-related injuries: a cross-sectional analysis

2020 ◽  
Vol 70 (8) ◽  
pp. 570-577
Author(s):  
J C Zhang ◽  
N Carnide ◽  
L Holness ◽  
P Cram
Keyword(s):  
Injury Risk ◽  
Cannabis Use ◽  
Cannabis User ◽  
Occupational Groups ◽  
Cross Sectional ◽  
Work Related ◽  
Cross Sectional Analysis ◽  
Work Related Injury ◽  
Sectional Analysis ◽  
The Impact

Abstract Background Although the association of cannabis use with automobile accidents has been well-studied, the impact of cannabis on workplace safety and injuries is less clear. Aims The purpose of this study was to examine the relationship between work-related injury and cannabis use in the past year. Methods We performed a cross-sectional analysis of the Canadian Community Health Survey (2013–16) of working individuals. We used multiple logistic regression modelling to calculate the odds of experiencing a work-related injury (defined as non-repetitive strain injury) among workers who reported using cannabis more than once during the prior 12 months as compared to non-users. We repeated the analysis among participants working in high injury risk occupational groups only. Results Among the 136 536 working participants, 2577 (2%) had a work-related injury in the last 12 months. Of these 2577 who had a work-related injury, 4% also reported being a cannabis user in the same period. We found no association between past-year cannabis use and work-related injury (odds ratio for work injury among users 0.81, 95% confidence interval 0.66–0.99). The association was unchanged in the subgroup analysis limited to high injury risk occupational groups. Conclusions We found no evidence that cannabis users experienced higher rates of work-related injuries. While awaiting prospective studies, occupational medicine practitioners should take a risk-based approach to drafting workplace cannabis policies.

Effects of eccentric training on mechanical properties of the plantar flexor muscle-tendon complex

2013 ◽  
Vol 114 (5) ◽  
pp. 523-537 ◽  
Author(s):  
Alexandre Fouré ◽  
Antoine Nordez ◽  
Christophe Cornu
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Plantar Flexion ◽  
Triceps Surae ◽  
Elastic Component ◽  
Plantar Flexor ◽  
Eccentric Training ◽  
Tendon Stiffness ◽  
Series Elastic Component ◽  
Series Elastic

Eccentric training is a mechanical loading classically used in clinical environment to rehabilitate patients with tendinopathies. In this context, eccentric training is supposed to alter tendon mechanical properties but interaction with the other components of the muscle-tendon complex remains unclear. The aim of this study was to determine the specific effects of 14 wk of eccentric training on muscle and tendon mechanical properties assessed in active and passive conditions in vivo. Twenty-four subjects were randomly divided into a trained group ( n = 11) and a control group ( n = 13). Stiffness of the active and passive parts of the series elastic component of plantar flexors were determined using a fast stretch during submaximal isometric contraction, Achilles tendon stiffness and dissipative properties were assessed during isometric plantar flexion, and passive stiffness of gastrocnemii muscles and Achilles tendon were determined using ultrasonography while ankle joint was passively moved. A significant decrease in the active part of the series elastic component stiffness was found ( P < 0.05). In contrast, a significant increase in Achilles tendon stiffness determined under passive conditions was observed ( P < 0.05). No significant change in triceps surae muscles and Achilles tendon geometrical parameters was shown ( P > 0.05). Specific changes in muscle and tendon involved in plantar flexion are mainly due to changes in intrinsic mechanical properties of muscle and tendon tissues. Specific assessment of both Achilles tendon and plantar flexor muscles allowed a better understanding of the functional behavior of the muscle-tendon complex and its adaptation to eccentric training.

Influence of Badminton Practice on Age-Related Changes in Patellar and Achilles Tendons

2020 ◽  
pp. 1-9
Author(s):  
Alfredo Bravo-Sánchez ◽  
Pablo Abián ◽  
Filipa Sousa ◽  
Fernando Jimenez ◽  
Javier Abián-Vicén
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Age Groups ◽  
Control Group ◽  
Physically Active ◽  
Tendon Stiffness ◽  
Sport Practice ◽  
Age Related ◽  
Age Related Changes

Regular sport practice could prevent age-related changes in tendinous tissues. The purpose of the study was to investigate the effect of regular badminton practice on patellar and Achilles tendon mechanical properties in senior competitive badminton players (>35 years old) and to compare the results with physically active people matched by age. One hundred ninety-two badminton players and 193 physically active people were divided by age into four groups, between 35 and 44 (U45), between 45 and 54 (U55), between 55 and 64 (U65), and over 65 (O65) years old. A LogiqS8 transducer in elastography mode and a MyotonPRO myotonometer were used to assess patellar and Achilles mechanical properties. Achilles tendon stiffness was higher in the control group than the badminton players for the U45, U55, and O65 age groups (p < .01). Also, the elastography index was higher in the control group than the badminton players for the U45, U55, U65, and O65 age groups (p < .05). In conclusion, regular badminton practice could prevent the decline in mechanical properties of the patellar and Achilles tendons.

A cross-sectional study on the mechanical properties of the Achilles tendon with growth

2017 ◽  
Vol 118 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Yasuyoshi Mogi ◽  
Suguru Torii ◽  
Yasuo Kawakami ◽  
Toshimasa Yanai
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional

scholarly journals Shear wave and strain sonoelastography for the evaluation of the Achilles tendon during isometric contractions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Alessandro Schneebeli ◽  
Ilaria Fiorina ◽  
Chandra Bortolotto ◽  
Marco Barbero ◽  
Deborah Falla ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reference Material ◽  
Achilles Tendon ◽  
Shear Wave ◽  
Shear Wave Elastography ◽  
Strain Ratio ◽  
Achilles Tendinopathy ◽  
Isometric Contractions ◽  
Tendon Stiffness ◽  
Healthy Participants

Abstract Objectives Changes in mechanical loading as well as pathology can modify the Achilles tendon mechanical properties and therefore detection of these changes is relevant for the diagnosis and management of Achilles tendinopathy. The aim of this study was to evaluate strain and shear wave sonoelastography for their ability to detect changes in the Achilles tendon mechanical properties during a series of isometric contractions. Methods Longitudinal sonoelastography images of the Achilles tendon were acquired from 20 healthy participants using four different ultrasound devices; two implementing strain sonoelastography technology (SE1, SE2) and two, shear wave elastography technology (SWE1, SWE2). Results SE1 measured a decreasing strain ratio (tendon become harder) during the different contraction levels from 1.51 (0.92) to 0.33 (0.16) whereas SE2 mesaured a decreasing strain ratio from 1.08 (0.76) to 0.50 (0.32). SWE1 measured decreasing tendon stiffness during contractions of increasing intensity from 33.40 (19.61) to 16.19 (2.68) whereas SWE2 revealed increasing tendon stiffness between the first two contraction levels from 428.65 (131.5) kPa to 487.9 (121.5) kPa followed by decreasing stiffness for the higher contraction levels from 459.35 (113.48) kPa to 293.5 (91.18) kPa. Conclusions Strain elastography used with a reference material was able to detect elasticity changes between the different contraction levels whereas shear wave elastography was less able to detect changes in Achilles tendon stiffness when under load. Inconsistent results between the two technologies should be further investigated.

scholarly journals Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6764 ◽  
Author(s):  
Amelie Werkhausen ◽  
Neil J. Cronin ◽  
Kirsten Albracht ◽  
Gøran Paulsen ◽  
Askild V. Larsen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Achilles Tendon ◽  
Stance Phase ◽  
Training Group ◽  
Triceps Surae ◽  
Control Group ◽  
Tendon Stiffness ◽  
Strain Pattern ◽  
Tendon Strain ◽  
Triceps Surae Muscles

Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric single-leg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18% (P < 0.01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P < 0.01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple in-series models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.

scholarly journals Influence of Charge Quality on Physical, Mechanical and Operational Properties of Low-Alloy Steel 30KHGSA

2020 ◽  
Vol 24 (2) ◽  
pp. 17-36
Author(s):  
N. N. Sergeev ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
I. V. Tikhonova ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Alloy Steel ◽  
Relative Elongation ◽  
Temper Brittleness ◽  
Low Alloy Steel ◽  
Cross Sectional ◽  
Tempering Temperature ◽  
Working Length ◽  
The Impact

Purpose of reseach is to study the influence of the quality of the original charge on the complex of physical, mechanical and operational properties of structural low-alloy steel 30HGSA.Methods. As an object of research, a typical representative of low-alloy structural steels has been chosen - steel 30HGSA, smelted using metallized sponge iron pellets, ordinary scrap metal and billets obtained by the method of a boiling slag layer. In accordance with the set objectives of the study, steel 30HGSA of various melts, obtained with different charge, had the same conditions for melting, evacuation, deoxidation, casting and crystallization. The casting temperature was 1600...1620 оC and the post-vacuum treatment temperature was 1530...1560 °C. Duration of evacuation - 5 minutes. Casting of melts was carried out into cast iron molds with a siphon for 4 ... 5 minutes. Deoxidation was carried out in a ladle with aluminum in the amount of 4 ... 4.5 kg / melt. After solidification, the ingots were cooled in special wells. The ingots were cut into 3 parts: head, middle and bottom (600 × 600 mm). The middle part was then hot forged and rolled to a Ø30 mm bar. The length of the rod was 2 ... 3.4 m. After hot deformation, the rods were cooled in air.Results. Mechanical tests have been carried out. Statistical processing of experimental results has been performed. Regularities of changes in the characteristics of mechanical properties have been revealed: tensile strength, creep strength, relative narrowing of the cross-sectional area of the sample, relative elongation of the initial working length, impact strength (σВ, σ0.2, ψ, δ, aН).Conclusion. It has been found that with an increase in temperature, the mechanical properties of steel 30HGSA, smelted on various charges, decrease. It has been established that the cold brittleness threshold of 30HGSA steel is lower for purer melts on spongy iron and intermediate product KShS, the value of impact toughness at low temperatures is higher than in melting on a conventional metallized charge. Noticeable softening begins at a tempering temperature of 300 °C The temperature of the maximum tempering brittleness for steel 30HGSA, melted on a conventional metallized charge, is 550 °C It is shown that steel 30HGSA smelted with a pure original charge (spongy iron) has a lower tendency to temper brittleness than steel smelted with a conventional charge. The value of the impact toughness of the steel of this melt is higher than that of the steel of conventional melting over the entire tempering temperature range.

scholarly journals Relationship between tendon structure, stiffness, gait patterns and patient reported outcomes during the early stages of recovery after an Achilles tendon rupture

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Didier Laurent ◽  
Lorcan Walsh ◽  
Amir Muaremi ◽  
Nicolau Beckmann ◽  
Eckhard Weber ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Shear Wave ◽  
Plantar Pressure ◽  
Patient Reported Outcomes ◽  
Clinical Decision Making ◽  
Ex Vivo ◽  
Achilles Tendon Rupture ◽  
Tendon Stiffness ◽  
Patient Reported ◽  
The Impact

AbstractAfter an Achilles tendon (AT) injury, the decision to return to full weightbearing for the practice of sports or strenuous activities is based on clinical features only. In this study, tendon stiffness and foot plantar pressure, as objective quantitative measures that could potentially inform clinical decision making, were repeatedly measured in 15 patients until 3 months after the AT rupture by using shear wave elastography (SWE) and wearable insoles, respectively. Meanwhile, patient reported outcomes assessing the impact on physical activity were evaluated using the Achilles Tendon Total Rupture Score (ATRS). At week-2 post-injury, stiffness of the injured tendon varied from 6.00 ± 1.62 m/s (mean ± SD) close to the rupture to 8.91 ± 2.29 m/s when measured more distally. While near complete recovery was observed in distal and middle regions at week-8, the shear wave velocity in the proximal region recovered to only 65% of the contralateral value at week-12. In a parallel pre-clinical study, the tendon stiffness measured in vivo by SWE in a rat model was found to be strongly correlated with ex vivo values of the Young’s modulus, which attests to the adequacy of SWE for these measures. The insole derived assessment of the plantar pressure distribution during walking showed slight sub-optimal function of the affected foot at week-12, while the ATRS score recovered to a level of 59 ± 16. Significant correlations found between tendon stiffness, insole variables and distinct ATRS activities, suggest clinical relevance of tendon stiffness and foot plantar pressure measurements. These results illustrate how an alteration of the AT structure can impact daily activities of affected patients and show how digital biomarkers can track recovery in function over time.

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