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Huub Maas - One of the best experts on this subject based on the ideXlab platform.
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altered Mechanical Interaction between rat plantar flexors due to changes in intermuscular connectivity
Scandinavian Journal of Medicine & Science in Sports, 2017Co-Authors: Michel Bernabei, J H Van Dieen, Huub MaasAbstract:Connective tissue formation following muscle injury and remedial surgery may involve changes in the stiffness and configuration of the connective tissues linking adjacent muscles. We investigated changes in Mechanical Interaction of muscles by implanting either a tissue-integrating mesh (n = 8) or an adhesion barrier (n = 8) to respectively increase or decrease the intermuscular connectivity between soleus muscle (SO) and the lateral gastrocnemius and plantaris complex (LG+PL) of the rat. As a measure of Mechanical Interaction, changes in SO tendon forces and proximal-distal LG+PL force differences in response to lengthening LG+PL proximally were assessed 1 and 2 weeks post-surgery. The extent of Mechanical Interaction was doubled 1 week post-implantation of the tissue-integrating mesh compared to an unaffected compartment (n = 8), and was more than four times higher 2 weeks post-surgery. This was found only for maximally activated muscles, but not when passive. Implanting the adhesion barrier did not result in a reduction of the Mechanical Interaction between these muscles. Our findings indicate that the ratio of force transmitted via myofascial, rather than myotendinous pathways, can increase substantially when the connectivity between muscles is enhanced. This improves our understanding of the consequences of connective tissue formation at the muscle boundary on skeletal muscle function.
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synergistic co activation increases the extent of Mechanical Interaction between rat ankle plantar flexors
Frontiers in Physiology, 2016Co-Authors: Chris Tijs, Jaap H Van Dieen, Guus C Baan, Huub MaasAbstract:Force transmission between rat ankle plantar-flexors has been found for physiological muscle lengths and relative positions, but only with all muscles maximally activated. The aims of this study were to assess intermuscular Mechanical Interactions between ankle plantar-flexors during (i) fully passive conditions, (ii) excitation of soleus (SO), (iii) excitation of lateral gastrocnemius (LG), and (iv) during co-activation of SO and LG (SO&LG). We assessed effects of proximal lengthening of LG and plantaris (PL) muscles (i.e. simulating knee extension) on forces exerted at the distal SO tendon (FSO) and on the force difference between the proximal and distal LG+PL tendons (ΔFLG+PL) of the rat. LG+PL lengthening increased FSO to a larger extent (p=0.017) during LG excitation (0.0026 N/mm) than during fully passive conditions (0.0009 N/mm). Changes in FSO in response to LG+PL lengthening were lower (p=0.002) during SO only excitation (0.0056 N/mm) than during SO&LG excitation (0.0101 N/mm). LG+PL lengthening changed ∆FLG+PL to a larger extent (p=0.007) during SO excitation (0.0211 N/mm) than during fully passive conditions (0.0157 N/mm). In contrast, changes in ∆FLG+PL in response to LG+PL lengthening during LG excitation (0.0331 N/mm) were similar (p=0.161) to that during SO&LG excitation (0.0370 N/mm). In all conditions, changes of FSO were lower than those of ∆FLG+PL. This indicates that muscle forces were transmitted not only between LG+PL and SO, but also between LG+PL and other surrounding structures. In addition, epimuscular myofascial force transmission between rat ankle plantar-flexors was enhanced by muscle activation. However, the magnitude of this Interaction was limited.
Maas Huub - One of the best experts on this subject based on the ideXlab platform.
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Changes in muscle-tendon unit length-force characteristics following experimentally induced photothrombotic stroke cannot be explained by changes in muscle belly structure.
'Springer Science and Business Media LLC', 2021Co-Authors: Paudyal Arjun, Degens Hans, Baan, Guus C, Noort Wendy, Slevin Mark, Van Wegen Erwin, Kwakkel Gert, Maas HuubAbstract:Purpose The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and Mechanical properties of rat m. flexor carpi ulnaris. Methods Two groups of Young-adult male Sprague–Dawley rats were measured: stroke (n = 9) and control (n = 7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscle–tendon unit and muscle belly length–force characteristics of the m. flexor carpi ulnaris, Mechanical Interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured. Results Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscle–tendon unit length, but only for the passive conditions. Stroke did not alter the length–force characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of Mechanical Interaction with m. palmaris longus muscle. Conclusion The higher passive force and passive stiffness at the muscle–tendon unit level in the absence of changes in structural and Mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon
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Changes in muscle–tendon unit length–force characteristics following experimentally induced photothrombotic stroke cannot be explained by changes in muscle belly structure
'Springer Science and Business Media LLC', 2021Co-Authors: Paudyal Arjun, Degens Hans, Baan, Guus C, Noort Wendy, Slevin Mark, Van Wegen Erwin, Kwakkel Gert, Maas HuubAbstract:Purpose: The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and Mechanical properties of rat m. flexor carpi ulnaris. Methods: Two groups of Young-adult male Sprague–Dawley rats were measured: stroke (n = 9) and control (n = 7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscle–tendon unit and muscle belly length–force characteristics of the m. flexor carpi ulnaris, Mechanical Interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured. Results: Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscle–tendon unit length, but only for the passive conditions. Stroke did not alter the length–force characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of Mechanical Interaction with m. palmaris longus muscle. Conclusion: The higher passive force and passive stiffness at the muscle–tendon unit level in the absence of changes in structural and Mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon
Louis J Soslowsky - One of the best experts on this subject based on the ideXlab platform.
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Interaction between the supraspinatus and infraspinatus tendons effect of anterior supraspinatus tendon full thickness tears on infraspinatus tendon strain
American Journal of Sports Medicine, 2009Co-Authors: Nelly Andarawispuri, Eric T Ricchetti, Louis J SoslowskyAbstract:Background: Rotator cuff tears are common and not well-understood shoulder problems. Structural and Mechanical inhomogeneity of the supraspinatus tendon complicates accurate prediction of risk of tear propagation and may affect appropriate clinical treatment.Hypothesis: We propose that Interactions between the supraspinatus and infraspinatus tendons are critical to load bearing at the glenohumeral joint and warrant investigation.Study Design: Controlled laboratory study.Methods: Principal strains in the infraspinatus tendon of cadaveric human shoulders were evaluated with increasing anterior full-thickness supraspinatus tendon tear sizes and loading to evaluate whether a Mechanical Interaction between the supraspinatus and infraspinatus tendons exists. A constant nominal load was attached to the infraspinatus throughout all experimental conditions.Results: Increasing supraspinatus tendon tear width from intact and 33% to 66% and increasing supraspinatus tendon load caused an increase in maximum and a decr...
T G Davies - One of the best experts on this subject based on the ideXlab platform.
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lattice modelling of corrosion induced cracking and bond in reinforced concrete
Cement & Concrete Composites, 2011Co-Authors: P. Grassl, T G DaviesAbstract:Abstract A lattice approach is used to describe the Mechanical Interaction of a corroding reinforcement bar, the surrounding concrete and the interface between steel reinforcement and concrete. The cross-section of the ribbed reinforcement bar is taken to be circular, assuming that the Interaction of the ribs and the surrounding concrete can be captured by a cap-plasticity interface model. The expansive corrosion process is represented by an Eigenstrain in the lattice elements forming the interface between concrete and reinforcement. Several pull-out tests with varying degree of corrosion are analysed. The numerical results are compared with experiments reported in the literature. The influence of the properties of concrete are studied. The proposed lattice approach offers insight into corrosion induced cracking and its influence on bond strength.
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lattice modelling of corrosion induced cracking and bond in reinforced concrete
arXiv: Materials Science, 2011Co-Authors: P. Grassl, T G DaviesAbstract:A lattice approach is used to describe the Mechanical Interaction of a corroding reinforcement bar, the surrounding concrete and the interface between steel reinforcement and concrete. The cross-section of the ribbed reinforcement bar is taken to be circular, assuming that the Interaction of the ribs of the deformed reinforcement bar and the surrounding concrete can be captured by a cap-plasticity interface model. The expansive corrosion process is represented by an Eigenstrain in the lattice elements forming the interface between concrete and reinforcement. Several pull-out tests with varying degree of corrosion are analysed. The numerical results are compared with experiments reported in the literature. The influence of the properties of concrete are studied. The proposed lattice approach offers insight into corrosion induced cracking and its influence on bond strength.
Paudyal Arjun - One of the best experts on this subject based on the ideXlab platform.
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Changes in muscle-tendon unit length-force characteristics following experimentally induced photothrombotic stroke cannot be explained by changes in muscle belly structure.
'Springer Science and Business Media LLC', 2021Co-Authors: Paudyal Arjun, Degens Hans, Baan, Guus C, Noort Wendy, Slevin Mark, Van Wegen Erwin, Kwakkel Gert, Maas HuubAbstract:Purpose The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and Mechanical properties of rat m. flexor carpi ulnaris. Methods Two groups of Young-adult male Sprague–Dawley rats were measured: stroke (n = 9) and control (n = 7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscle–tendon unit and muscle belly length–force characteristics of the m. flexor carpi ulnaris, Mechanical Interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured. Results Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscle–tendon unit length, but only for the passive conditions. Stroke did not alter the length–force characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of Mechanical Interaction with m. palmaris longus muscle. Conclusion The higher passive force and passive stiffness at the muscle–tendon unit level in the absence of changes in structural and Mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon
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Changes in muscle–tendon unit length–force characteristics following experimentally induced photothrombotic stroke cannot be explained by changes in muscle belly structure
'Springer Science and Business Media LLC', 2021Co-Authors: Paudyal Arjun, Degens Hans, Baan, Guus C, Noort Wendy, Slevin Mark, Van Wegen Erwin, Kwakkel Gert, Maas HuubAbstract:Purpose: The aim of this study was to assess the effects of experimentally induced photothrombotic stroke on structural and Mechanical properties of rat m. flexor carpi ulnaris. Methods: Two groups of Young-adult male Sprague–Dawley rats were measured: stroke (n = 9) and control (n = 7). Photothrombotic stroke was induced in the forelimb region of the primary sensorimotor cortex. Four weeks later, muscle–tendon unit and muscle belly length–force characteristics of the m. flexor carpi ulnaris, Mechanical Interaction with the neighbouring m. palmaris longus, the number of sarcomeres in series within muscle fibres, and the physiological cross-sectional area were measured. Results: Stroke resulted in higher force and stiffness of the m. flexor carpi ulnaris at optimum muscle–tendon unit length, but only for the passive conditions. Stroke did not alter the length–force characteristics of m. flexor carpi ulnaris muscle belly, morphological characteristics, and the extent of Mechanical Interaction with m. palmaris longus muscle. Conclusion: The higher passive force and passive stiffness at the muscle–tendon unit level in the absence of changes in structural and Mechanical characteristics of the muscle belly indicates that the experimentally induced stroke resulted in an increased stiffness of the tendon
