Search results for "Achilles Tendon"
showing 10 items of 101 documents
6 Self-organising Maps To Analyse Effects Of Low Intensity Concentric Combined With Blood Flow Restriction
2014
Introduction Self-Organising Maps (SOM) are a type of Artificial Neural Network (ANN) model used to visualise multidimensional data [Kohonen-00]. SOM provides a correspondence between the original N-dimensional space and a twodimensional space [Haykin-08]. In the case presented in this work, this means that two subjects with similar values of the different variables should appear near in the two-dimensional space [Kohonen-00], [Haykin-08]. Method In order to test this method, 15 athletes were selected. Subjects’ measurements were performed in three different periods: before the exercise test, immediately after performing the exercise and twenty-four hours later. The control measures were th…
Achilles tendon ultrasonography may detect early features of psoriatic arthropathy in those with cutaneous psoriasis
2014
Influence of structure on the tissue dynamics of the human soleus muscle observed in MRI studies during isometric contractions.
2006
This article investigates how the internal structure of muscle and its relationship with tendon and even skeletal structures influence the translation of muscle fiber contractions into movement of a limb. Reconstructions of the anatomy of the human soleus muscle from the Visible Human Dataset (available from the National Library of Medicine), magnetic resonance images (MRI), and cadaver studies revealed a complex 3D connective tissue structure populated with pennate muscle fibers. The posterior aponeurosis and the median septum of the soleus form the insertion of the muscle and are continuous with the Achilles tendon. The distal extremities of the pennate muscle fibers attach to these struc…
The effects of immobilization on the quality of Achilles tendon in rats
2007
Immobilization of an Achilles tendon in a shortened position for 1 and 3 weeks did not change pyridinoline and mature collagen concentrations. Although a significant decrease in the biosynthesis of collagen was observed simultaneously in the soleus muscle of the same hindlimb, these results suggest that the stability of collagen provided by the nonreducible cross-link, pyridinoline, is not altered during this type of immobilization. The significance of stable cross-links for the known decrease in tensile strength during immobilization remains open.
Effect of a common exercise programme with an individualised progression criterion based on the measurement of neuromuscular capacity versus current …
2021
IntroductionHigh-load resistance training has shown positive effects in pain and function in lower limb tendinopathies. However, some authors suggest that current exercise programmes produce an increase in tolerance to load and exercise in general but without fixing some existing issues in tendinopathy. This may indicate the need to include training aspects not currently taken into account in the current programmes. The main objective of this study will be to compare the effect of a common exercise protocol for the three predominant lower limb tendinopathies (Achilles, patellar and gluteal), based on an individualised control of the dose and training of specific aspects of the neuromuscular…
Muscle-tendon morphomechanical properties of non-surgically treated Achilles tendon 1-year post-rupture
2022
Background\ud Achilles tendon rupture appears to alter stiffness and length of the tendon. These alterations may affect the function of tendon in force transmission and in energy storage and recovery. We studied the mechanical properties of the Achilles' tendon post-rupture and their association with function.\ud Methods\ud Twenty-four (20 males, 4 females) participants (mean age: 43 y, 176 cm, 81 kg) were recruited. Ultrasonography and dynamometry were used to assess the muscle-tendon unit morphological and mechanical properties of non-surgically treated patients 1-year post rupture.\ud Findings\ud Injured tendons were longer with difference of 1.8 cm (95%CI: 0.5–1.9 cm; P < 0.001), and th…
Non-uniformity of displacement and strain within the Achilles tendon is affected by joint angle configuration and differential muscle loading.
2020
Although the Achilles tendon (AT) has been studied for more than a century, a complete understanding of the mechanical and functional consequences of AT structural organization is currently lacking. The aim of this study was to assess how joint angle configuration affects subtendon displacement and strain of soleus (SOL) and lateral gastrocnemius (LG) muscles. Knots sutured onto SOL and LG subtendons of 12 Wistar rats, were videotaped to quantify displacements and the ankle torque was assessed for different isometric activation conditions (i.e., individual and simultaneous) of the triceps surae muscles. Changing ankle and knee joint angle affected the magnitude of displacement, relative dis…
Mechanical Coupling Between Muscle-Tendon Units Reduces Peak Stresses
2017
The presence of mechanical linkages between synergistic muscles and their common tendons may distribute forces among the involved structures. We review studies, using humans and other animals, examining muscle and tendon interactions and discuss the hypothesis that connections between muscle bellies and within tendons may serve as a mechanism to distribute forces and mitigate peak stresses. peerReviewed
Non‐uniform displacement within ruptured Achilles tendon during isometric contraction
2021
The purpose of this study was investigate tendon displacement patterns in non‐surgically treated patients 14 months after acute Achilles tendon rupture (ATR) and to classify patients into groups based on their Achilles tendon (AT) displacement patterns. Twenty patients were tested. Sagittal images of AT were acquired using B‐mode ultrasonography during ramp contractions at a torque level corresponding to 30% of the maximal isometric plantarflexion torque of the uninjured limb. A speckle tracking algorithm was used to track proximal‐distal movement of the tendon tissue at 6 antero‐posterior locations. Two‐way repeated measures ANOVA for peak tendon displacement was performed. K‐means cluster…
Approximation of pre-twisted Achilles sub-tendons with continuum beam elements
2022
Achilles sub-tendons are materially and geometrically challenging structures that can nearly undergo around 15% elongation from their pre-twisted initial states during physical activities. Sub-tendons' cross-sectional shapes are subject-specific, varying from simple to complicated. Therefore, the Achilles sub-tendons are often described by three-dimensional elements that lead to a remarkable number of degrees of freedom. On the other hand, the continuum-based beam elements in the framework of the absolute nodal coordinate formulation have already been shown to be a reliable and efficient replacement for the three-dimensional continuum elements in some special problems. So far, that element …