Biomechanical and structural parameters of tendons in rats subjected to swimming exercise.

The aim of this study was to evaluate the effect of swimming exercise, without overloading, on the biomechanical parameters of the calcaneal tendon of rats. 27 male Wistar rats (70 days) were distributed randomly into 2 groups, Control Group (CG; n=15) with restricted movements inside the cage and Swimming Group (SG; n=12), subjected to exercise training in a tank with a water temperature of 30±1°C, for 1 h/day, 5 days/week for 8 weeks. All animals were kept in a reversed light/dark cycle of 12 h with access to food and water ad libitum. After that, they were anesthetized and had their calcaneus tendons collected from their left rear paws. The tendon was submitted to a mechanical test on a conventional test machine. From the stress vs. strain curve, the biomechanical data were analyzed. For the statistical analysis, the Student-T test was used (p<0.05). Of the variables examined, the maximum tension (p=0.009), maximum force (p=0.03), energy of deformation/tendon cross sectional area (p=0.017) and elastic modulus of the tendon (p=0.013) showed positive outcomes in SG. There was no difference in the other parameters. The results indicate that the swimming exercise training, without overloading, was an important stimulus for improving the biomechanical parameters and structural properties of the calcaneal tendon.

Does aerobic exercise training promote changes in structural and biomechanical properties of the tendons in experimental animals? A systematic review.

To develop a systematic review to evaluate, through the best scientific evidence available, the effectiveness of aerobic exercise in improving the biomechanical characteristics of tendons in experimental animals. Two independent assessors conducted a systematic search in the databases Medline/PUBMED and Lilacs/BIREME, using the following descriptors of Mesh in animal models. The ultimate load of traction and the elastic modulus tendon were used as primary outcomes and transverse section area, ultimate stress and tendon strain as secondary outcomes. The assessment of risk of bias in the studies was carried out using the following methodological components: light/dark cycle, temperature, nutrition, housing, research undertaken in conjunction with an ethics committee, randomization, adaptation of the animals to the training and preparation for the mechanical test. Eight studies, comprising 384 animals, were selected; it was not possible to combine them into one meta-analysis due to the heterogeneity of the samples. There was a trend to increasing ultimate load without changes in the other outcomes studied. Only one study met more than 80% of the quality criteria. Physical training performed in a structured way with imposition of overloads seems to be able to promote changes in tendon structure of experimental models by increasing the ultimate load supported. However, the results of the influence of exercise on the elastic modulus parameters, strain, transverse section area and ultimate stress, remain controversial and inconclusive. Such a conclusion must be evaluated with reservation as there was low methodological control in the studies included in this review.

Alterations of tendons in patients with diabetes mellitus: a systematic review.

AIMS: To perform a systematic review of observational studies which analyse tendon alterations in patients with diabetes mellitus compared with healthy individuals. METHODS: Data collection was performed, with no language restriction, using the databases of PubMed/Medline, BIREME, CINAHL, LILACS and Cochrane, as well as the references found in these studies. Three reviewers performed independent extractions of articles. Subsequently, these reviewers analysed the articles, focusing on their methodological quality, using the appropriate scale to evaluate observational studies from the Agency for Healthcare Research and Quality. RESULTS: Six articles were included in the analysis. Of these, four had used ultrasonographic diagnostics, one computed tomography and one magnetic resonance imaging. The patient pool comprised 396 individuals. All the articles evaluated tendon thickness and presented heterogeneous results. Two articles stated thickening or increased volume of the tendons in diabetic people, one article did not report any alteration, the fourth failed to determine any alterations and the fifth showed thinning of the tendons. The arrangement of collagen fibrils and the presence of calcification were analysed in only one article (n = 80), showing that 88.10% (n = 68) of individuals with diabetes presented disorientation of collagen fibril arrangement, while only 10% (n = 1) of healthy individuals presented this condition. Regarding tendon calcification, the article showed diabetic individuals with higher values than healthy individuals. CONCLUSIONS: All the articles indicated some relation between diabetes mellitus and tendon alterations in human beings, but due to methodological drawbacks, this association could not be sustained.

Dissection of the stylohyoid chain: a method of approach

La cadena estilohioídea está mereciendo, considerable atención debido a la gran incidencia del alargue de uno de sus elementos llamado proceso estiloide del hueso temporal, que caracteriza al Síndromede Eagle, llegando a alcanzar el 28 por ciento de la población. Nuestro trabajo tiene como objetivo describir un método de disección macroscópica para un abordaje de la cadena estilohioídea. Utilizando 15 regiones del cuello de cadáveres humanos, de sexo masculino se obtuvieron 30 cadenas estilohioídeas a través del método de disección macroscópica, observándose que el método de acceso por etapas, a partir de ambas extremidades de la cadena, es el que ofrece menor riesgo de lesión del ligamento estiloihíodeo preservándose, de esta manera, la integridad de la cadena estilohioídea