scholarly journals Load specific patellar and Achilles tendon adaptation: Structural integrity or function?

2017 ◽  
Vol 66 (1) ◽  
pp. 77-77
Author(s):  
Hans-Peter Wiesinger ◽  
Florian Rieder ◽  
Alexander Kösters ◽  
Erich Müller ◽  
Olivier R. Seynnes
Keyword(s):  
Achilles Tendon ◽  
Structural Integrity ◽  
Tendon Adaptation

The effect of running, strength, and vibration strength training on the mechanical, morphological, and biochemical properties of the Achilles tendon in rats

2007 ◽  
Vol 102 (2) ◽  
pp. 564-572 ◽  
Author(s):  
Kirsten Legerlotz ◽  
Peter Schjerling ◽  
Henning Langberg ◽  
Gert-Peter Brüggemann ◽  
Anja Niehoff
Keyword(s):  
Growth Factor ◽  
Achilles Tendon ◽  
Muscle Mass ◽  
Gastrocnemius Muscle ◽  
Biochemical Properties ◽  
Tissue Growth ◽  
Vibration Strength ◽  
Mrna Concentration ◽  
Collagen Iii ◽  
Tendon Adaptation

Compared with muscle or bone, there is a lack of information about the relationship between tendon adaptation and the applied loading characteristic. The purpose of the present study was to analyze the effect of different exercise modes characterized by very distinct loading patterns on the mechanical, morphological, and biochemical properties of the Achilles tendon. Sixty-four female Sprague-Dawley rats were divided into five groups: nonactive age-matched control (AMC; n = 20), voluntary wheel running (RT; n = 20), vibration strength-trained (LVST; n = 12), high-vibration strength-trained (HVST; n = 6), and high strength-trained (HST; n = 6) group. After a 12-wk-long experimental period, the Achilles tendon was tested mechanically and the cross-sectional area, the soleus and gastrocnemius muscle mass, and mRNA concentration of collagen I, collagen III, tissue inhibitor of metalloproteinase-1 (TIMP-1), transforming growth factor-β, connective tissue growth factor, and matrix metalloproteinase-2 was determined. Neither in the LVST nor in the HVST group could any adaptation of the Achilles tendon be detected, although the training had an effect on the gastrocnemius muscle mass in the LVST group ( P < 0.05). In the HST group, the highest creep was found, but the effect was more pronounced compared with the LVST group ( P < 0.05) than with the AMC group. That indicates that this was rather induced by the low muscle mass rather than by training. However, the RT group had a higher TIMP-1 mRNA concentration in the Achilles tendon in contrast to AMC group ( P < 0.05), which suggests that this exercise mode may have an influence on tendon adaptation.

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 &lt; 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.

scholarly journals Achilles tendon adaptation and Achilles tendinopathy in running

2013 ◽  
Vol 1 (3) ◽  
Author(s):  
E Maas ◽  
I Jonkers ◽  
K Peers ◽  
B Vanwanseele
Keyword(s):  
Achilles Tendon ◽  
Achilles Tendinopathy ◽  
Tendon Adaptation

Achilles Tendon Doppler Flow May be Associated with Mechanical Loading among Active Athletes

2008 ◽  
Vol 36 (11) ◽  
pp. 2210-2215 ◽  
Author(s):  
Peter Malliaras ◽  
Paula J. Richards ◽  
Giorgio Garau ◽  
Nicola Maffulli
Keyword(s):  
Achilles Tendon ◽  
Mechanical Load ◽  
Color Doppler ◽  
Color Doppler Ultrasound ◽  
Cross Sectional Study ◽  
Activity Level ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Doppler Flow ◽  
Tendon Adaptation

Background Tendon Doppler flow may be associated with tendon pain in symptomatic patients, but the relationship between Doppler flow and pain among athletes who are still competing is unclear. Hypothesis Among active athletes, Doppler flow may partly reflect tendon adaptation to increased mechanical load and/or asymptomatic tendinopathy. Study Design Cross-sectional study; Level of evidence, 3. Methods The Achilles tendons of 61 badminton players (24 elite, 37 recreational) were examined with gray-scale and color Doppler ultrasound. Achilles tendon pain and activity level (badminton training, badminton playing, badminton years) were measured. Results Doppler flow was not associated with current Achilles tendon pain but was associated with an increased anteroposterior tendon diameter (an indicator of tendinopathy) ( P = .02). Athletes who had been playing badminton for longer were more likely to have Doppler flow ( P< .01), and there was a trend toward an association between a greater number of badminton playing hours per week and Doppler flow ( P = .07). Conclusion Achilles tendon Doppler flow appears to be a sign of asymptomatic tendinopathy rather than pain among active athletes. The association between weekly badminton hours and badminton years and Doppler flow suggests that Doppler flow may be a response to mechanical load in this cohort.

Achilles tendon adaptation in cross-country runners across a competitive season

2017 ◽  
Vol 28 (1) ◽  
pp. 303-310 ◽  
Author(s):  
L. E. Stanley ◽  
A. Lucero ◽  
T. C. Mauntel ◽  
M. Kennedy ◽  
N. Walker ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Competitive Season ◽  
Tendon Adaptation ◽  
Cross Country ◽  
Cross Country Runners

Structural Achilles tendon properties in athletes subjected to different exercise modes and in Achilles tendon rupture patients

2005 ◽  
Vol 99 (5) ◽  
pp. 1965-1971 ◽  
Author(s):  
M. Kongsgaard ◽  
P. Aagaard ◽  
M. Kjaer ◽  
S. P. Magnusson
Keyword(s):  
Achilles Tendon ◽  
Elite Athletes ◽  
Plantar Flexion ◽  
Achilles Tendon Rupture ◽  
Triceps Surae ◽  
Control Group ◽  
Endurance Running ◽  
Cross Sectional ◽  
Tendon Adaptation ◽  
Flexion Force

The prevalence of Achilles tendon (AT) injury is high in various sports, and AT rupture patients have been reported to have a 200-fold risk of sustaining a contralateral rupture. Tendon adaptation to different exercise modes is not fully understood. The present study investigated the structural properties of the AT in male elite athletes that subject their AT to different exercise modes as well as in Achilles rupture patients. Magnetic resonance imaging of the foot and leg, anthropometric measurements, and maximal isometric plantar flexion force were obtained in 6 male AT rupture patients and 25 male elite athletes (kayak/control group n = 9, volleyball n = 8 and endurance running n = 8). AT cross-sectional area (CSA) was normalized to body mass. Runners had a larger normalized AT CSA along the entire length of the tendon compared with the control group ( P < 0.05). The volleyball subjects had a larger normalized CSA compared with the control group ( P < 0.05) in the area of thinnest tendon CSA. No structural differences of the AT were found in the rupture subjects compared with the control group. Rupture subjects did not subject their AT to greater force or stress during a maximal voluntary isometric plantar flexion than the other groups. The CSA of the triceps surae musculature was the strongest predictor of AT CSA ( rs = 0.569, P < 0.001). This study is the first to show larger CSA in tendons that are subjected to intermittent high loads. AT rupture patients did not display differences in structural or loading properties of the tendons.

Electron Beam Damage of Biomolecules Assessed by Energy Loss Spectroscopy

1978 ◽  
Vol 36 (3) ◽  
pp. 61-69
Author(s):  
M. Isaacson ◽  
M.L. Collins ◽  
M. Listvan
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Structural Integrity ◽  
Analytical Electron Microscopy ◽  
High Dose ◽  
Dose Rates ◽  
Special Cases ◽  
Analytical Electron ◽  
Atom Migration ◽  
Beam Damage

Over the past five years it has become evident that radiation damage provides the fundamental limit to the study of blomolecular structure by electron microscopy. In some special cases structural determinations at very low doses can be achieved through superposition techniques to study periodic (Unwin & Henderson, 1975) and nonperiodic (Saxton & Frank, 1977) specimens. In addition, protection methods such as glucose embedding (Unwin & Henderson, 1975) and maintenance of specimen hydration at low temperatures (Taylor & Glaeser, 1976) have also shown promise. Despite these successes, the basic nature of radiation damage in the electron microscope is far from clear. In general we cannot predict exactly how different structures will behave during electron Irradiation at high dose rates. Moreover, with the rapid rise of analytical electron microscopy over the last few years, nvicroscopists are becoming concerned with questions of compositional as well as structural integrity. It is important to measure changes in elemental composition arising from atom migration in or loss from the specimen as a result of electron bombardment.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

High-Resolution electron crystallography of the light-harvesting chlorophyll-a/b protein complex from chloroplast membranes

1990 ◽  
Vol 48 (1) ◽  
pp. 610-610
Author(s):  
Werner Kühlbrandt ◽  
Da Neng Wang ◽  
K.H. Downing
Keyword(s):  
High Resolution ◽  
Electron Diffraction ◽  
Chlorophyll A ◽  
Protein Complex ◽  
Structural Integrity ◽  
Light Harvesting ◽  
Lhc Ii ◽  
Diffraction Patterns ◽  
Difference Fourier ◽  
2D Crystals

The light-harvesting chlorophyll-a/b protein complex (LHC-II) is the most abundant membrane protein in the chloroplasts of green plants where it functions as a molecular antenna of solar energy for photosynthesis. We have grown two-dimensional (2d) crystals of the purified, detergent-solubilized LHC-II . The crystals which measured 5 to 10 μm in diameter were stabilized for electron microscopy by washing with a 0.5% solution of tannin. Electron diffraction patterns of untilted 2d crystals cooled to 130 K showed sharp spots to 3.1 Å resolution. Spot-scan images of 2d crystals were recorded at 160 K with the Berkeley microscope . Images of untilted crystals were processed, using the unbending procedure by Henderson et al . A projection map of the complex at 3.7Å resolution was generated from electron diffraction amplitudes and high-resolution phases obtained by image processing .A difference Fourier analysis with the same image phases and electron diffraction amplitudes recorded of frozen, hydrated specimens showed no significant differences in the 3.7Å projection map. Our tannin treatment therefore does not affect the structural integrity of the complex.

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