{ "types" : { "Bookmark" : { "pluralLabel" : "Bookmarks" }, "Publication" : { "pluralLabel" : "Publications" }, "GoldStandardPublication" : { "pluralLabel" : "GoldStandardPublications" }, "GoldStandardBookmark" : { "pluralLabel" : "GoldStandardBookmarks" }, "Tag" : { "pluralLabel" : "Tags" }, "User" : { "pluralLabel" : "Users" }, "Group" : { "pluralLabel" : "Groups" }, "Sphere" : { "pluralLabel" : "Spheres" } }, "properties" : { "count" : { "valueType" : "number" }, "date" : { "valueType" : "date" }, "changeDate" : { "valueType" : "date" }, "url" : { "valueType" : "url" }, "id" : { "valueType" : "url" }, "tags" : { "valueType" : "item" }, "user" : { "valueType" : "item" } }, "items" : [ { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2e9294d19b2f705461fe8340bf970a6fb/inspo5", "tags" : [ "Fiber","Lateral","length","mechanics","matrix","heterogeneity","Extracellular","transmission","Endomysial","force","Sarcomere","bundle","connections" ], "intraHash" : "e9294d19b2f705461fe8340bf970a6fb", "interHash" : "7c13ec95eb31404c7683564d78305f64", "label" : "The impact of endomysium integrity on skeletal muscle fiber bundle mechanics", "user" : "inspo5", "description" : "", "date" : "2025-11-05 15:18:13", "changeDate" : "2025-11-05 15:18:13", "count" : 2, "pub-type": "article", "journal": "Journal of Biomechanics","publisher":"Elsevier BV", "year": "2025", "url": "http://dx.doi.org/10.1016/j.jbiomech.2025.112957", "author": [ "Paolo Carlo Danesini","André Tomalka","Tobias Siebert","Filiz Ates" ], "authors": [ {"first" : "Paolo Carlo", "last" : "Danesini"}, {"first" : "André", "last" : "Tomalka"}, {"first" : "Tobias", "last" : "Siebert"}, {"first" : "Filiz", "last" : "Ates"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "192","pages": "112957","abstract": "The endomysium, the innermost layer of the extracellular matrix (ECM), was shown to play an important role in both passive and active force transmission. However, its mechanical contribution within muscle fiber bundles remains incompletely understood. We hypothesized that dissecting one of the endomysial connections within a fiber bundle would alter force production and lead to changes in sarcomere lengths and their heterogeneity. Muscle fiber bundles (n = 12) were extracted from the extensor digitorum longus muscles of rats and chemically skinned. Their passive and active stress-length relationships were measured under two conditions: (i) with intact endomysium and (ii) after blunt dissection of endomysial connections between two adjacent peripheral fibers. Disruption of endomysial continuity significantly reduced passive stress by 26.5 % (p < 0.01) and active stress by 21.9 % (p < 0.001) on average across all lengths tested. It also shifted the optimal fiber length (Lopt) to longer values by 6.2 % (p < 0.01). Despite these mechanical changes, average sarcomere lengths (along fibers) and their heterogeneity remained unchanged. Length heterogeneity was only observed at a longer fiber length (1.3 Lopt) in the passive state before dissection. These findings demonstrate that endomysial connections are integral to the mechanical behavior of muscle fiber bundles, influencing both passive and active stress. The absence of sarcomere length changes along fibers suggests that other microstructural mechanisms, such as altered lattice spacing or impaired lateral force transmission, may underlie the observed changes. These results highlight the importance of ECM integrity in muscle mechanics and have implications for orthopedic interventions and neuromuscular disorder management.", "issn" : "0021-9290", "doi" : "10.1016/j.jbiomech.2025.112957", "bibtexKey": "Danesini_2025" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/26ae557bda4245c64d9be9293e67104dd/inspo5", "tags" : [ "Photogrammetric","pennation","geometry","length","Muscle","compartments","Fascicle","reconstruction","curvature" ], "intraHash" : "6ae557bda4245c64d9be9293e67104dd", "interHash" : "665b863a52d2c8a3419188684061b167", "label" : "Influence of muscle packing on the three-dimensional architecture of rabbit M. plantaris", "user" : "inspo5", "description" : "", "date" : "2024-12-19 16:44:48", "changeDate" : "2024-12-19 16:44:48", "count" : 3, "pub-type": "article", "journal": "Journal of the Mechanical Behavior of Biomedical Materials", "year": "2024", "url": "https://www.sciencedirect.com/science/article/pii/S1751616124003941?via%3Dihub", "author": [ "Mischa Borsdorf","Stefan Papenkort","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Mischa", "last" : "Borsdorf"}, {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "160","abstract": "In their physiological condition, muscles are surrounded by connective tissue, other muscles and bone. These tissues exert transverse forces that change the three-dimensional shape of the muscle compared to its isolated condition, in which all surrounding tissues are removed. A change in shape affects the architecture of a muscle and therefore its mechanical properties. The rabbit M. plantaris is a multi-pennate calf muscle consisting of two compartments. A smaller, bi-pennate inner muscle compartment is embedded in a larger, uni-pennate outer compartment (Böl et al., 2015). As part of the calf, the plantaris is tightly packed between other muscles. It is unclear how packing affects the shape and architecture of the plantaris. Therefore, we examined the isolated and packed plantaris of the contralateral legs of three rabbits to determine the influence of the surrounding muscles on its shape and architectural properties using photogrammetric reconstruction and manual digitization, respectively. In the packed condition, the plantaris showed a 27% increase in fascicle pennation and a 54% increase in fascicle curvature compared to the isolated condition. Fascicle length was not affected by muscle packing. The change in muscle architecture occurred mainly in the outer compartment of the plantaris. Furthermore, the isolated plantaris showed a more circular shape and a reduced width of its muscle belly. It can be concluded that the packed plantaris is flattened by the forces exerted by the surrounding muscles, causing a complex architectural change. The data provided improve our understanding of muscle packages in general and can be used to develop and validate realistic three-dimensional muscle models.", "language" : "English", "doi" : "10.1016/j.jmbbm.2024.106762", "bibtexKey": "siebert2024influence" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2d99121cf0e4d2bfa7c185360a86e038b/inspo5", "tags" : [ "area","Inspo","siebert","Aponeurosis","pennation","geometry","length","Muscle","compartments","Fascicle","curvature" ], "intraHash" : "d99121cf0e4d2bfa7c185360a86e038b", "interHash" : "816781b7dca07a6982acaabf86b1f62f", "label" : "Influence of muscle length on the three-dimensional architecture and aponeurosis dimensions of rabbit calf muscles", "user" : "inspo5", "description" : "", "date" : "2024-04-02 12:06:57", "changeDate" : "2024-04-02 12:06:57", "count" : 2, "pub-type": "article", "journal": "Journal of the Mechanical Behavior of Biomedical Materials","publisher":"Elsevier BV", "year": "2024", "url": "http://dx.doi.org/10.1016/j.jmbbm.2024.106452", "author": [ "Mischa Borsdorf","Stefan Papenkort","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Mischa", "last" : "Borsdorf"}, {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "152","pages": "106452","abstract": "The function of a muscle is highly dependent on its architecture, which is characterized by the length, pennation, and curvature of the fascicles, and the geometry of the aponeuroses. During in vivo function, muscles regularly undergo changes in length, thereby altering their architecture. During passive muscle lengthening, fascicle length (FL) generally increases and the angle of fascicle pennation (FP) and the fascicle curvature (FC) decrease, while the aponeuroses increase in length but decrease in width.\r\n\r\nMuscles are differently structured, making their change during muscle lengthening complex and multifaceted. To obtain comprehensive data on architectural changes in muscles during passive length, the present study determined the three-dimensional fascicle geometry of rabbit M. gastrocnemius medialis (GM), M. gastrocnemius lateralis (GL), and M. plantaris (PLA). For this purpose, the left and right legs of three rabbits were histologically fixed at targeted ankle joint angles of 95° (short muscle length [SML]) and 60° (long muscle length [LML]), respectively, and the fascicles were tracked by manual three-dimensional digitization. In a second set of experiments, the GM aponeurosis dimensions of ten legs from five rabbits were determined at varying muscle lengths via optical marker tracking.\r\n\r\nThe GM consisted of a uni-pennated compartment, whereas the GL and PLA contained multiple compartments of differently pennated fascicles. In the LML compared to the SML, the GM, GL, and PLA had on average a 41%, 29%, and 41% increased fascicle length, and a 30%, 25%, and 33% decrease in fascicle pennation and a 32%, 11%, and 35% decrease in fascicle curvature, respectively. Architectural properties were also differentiated among the different compartments of the PLA and GL, allowing for a more detailed description of their fascicle structure and changes. It was shown that the compartments change differently with muscle length. It was also shown that for each degree of ankle joint angle reduction, the proximal GM aponeurosis length increased by 0.11%, the aponeurosis width decreased by 0.22%, and the area was decreased by 0.20%. The data provided improve our understanding of muscles and can be used to develop and validate muscle models.", "language" : "English", "issn" : "1751-6161", "doi" : "10.1016/j.jmbbm.2024.106452", "bibtexKey": "Borsdorf_2024" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f3d78410850201349b3420cb0f71115a/inspo5", "tags" : [ "Stomach","Uniaxial","Force","experiments","velocity","length","layer","relationship","muscle","Contractile","Separated","tensile","wall","Organ","properties" ], "intraHash" : "f3d78410850201349b3420cb0f71115a", "interHash" : "b79cfd3a81cd8360cba0a6d4729f7452", "label" : "Influence of layer separation on the determination of stomach smooth muscle properties.", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 2, "pub-type": "article", "journal": "Pflugers Arch", "year": "2021", "url": "https://link.springer.com/article/10.1007/s00424-021-02568-5", "author": [ "Mischa Borsdorf","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Mischa", "last" : "Borsdorf"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "473","pages": "911-920","abstract": "Uniaxial tensile experiments are a standard method to determine the contractile properties of smooth muscles. Smooth muscle strips from organs of the urogenital and gastrointestinal tract contain multiple muscle layers with different muscle fiber orientations, which are frequently not separated for the experiments. During strip activation, these muscle fibers contract in deviant orientations from the force-measuring axis, affecting the biomechanical characteristics of the tissue strips. This study aimed to investigate the influence of muscle layer separation on the determination of smooth muscle properties. Smooth muscle strips, consisting of longitudinal and circumferential muscle layers (whole-muscle strips [WMS]), and smooth muscle strips, consisting of only the circumferential muscle layer (separated layer strips [SLS]), have been prepared from the fundus of the porcine stomach. Strips were mounted with muscle fibers of the circumferential layer inline with the force-measuring axis of the uniaxial testing setup. The force\u2013length (FLR) and force\u2013velocity relationships (FVR) were determined through a series of isometric and isotonic contractions, respectively. Muscle layer separation revealed no changes in the FLR. However, the SLS exhibited a higher maximal shortening velocity and a lower curvature factor than WMS. During WMS activation, the transversally oriented muscle fibers of the longitudinal layer shortened, resulting in a narrowing of this layer. Expecting volume constancy of muscle tissue, this narrowing leads to a lengthening of the longitudinal layer, which counteracted the shortening of the circumferential layer during isotonic contractions. Consequently, the shortening velocities of the WMS were decreased significantly. This effect was stronger at high shortening velocities.", "language" : "English", "doi" : "doi:10.1007/s00424-021-02568-5", "bibtexKey": "borsdorf2021influence" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2109b403efc1ed2df33dbe51dee5053a8/inspo5", "tags" : [ "Pennation","angle","Rabbit","length","Muscle","model","Fascicle","architecture","soleus" ], "intraHash" : "109b403efc1ed2df33dbe51dee5053a8", "interHash" : "fdf6fd718e0d6b5993e811c89f5ac2e6", "label" : "A simple geometrical model accounting for 3D muscle architectural changes across muscle lengths", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 2, "pub-type": "article", "journal": "Journal of Biomechanics","publisher":"Elsevier BV", "year": "2020", "url": "https://doi.org/10.1016%2Fj.jbiomech.2020.109694", "author": [ "Philipp Schenk","Stefan Papenkort","Markus Böl","Tobias Siebert","Roland Grassme","Christian Rode" ], "authors": [ {"first" : "Philipp", "last" : "Schenk"}, {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"}, {"first" : "Roland", "last" : "Grassme"}, {"first" : "Christian", "last" : "Rode"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "103","pages": "109694", "doi" : "10.1016/j.jbiomech.2020.109694", "bibtexKey": "Schenk_2020" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2ed947ea3f941527dbb669066bc155938/inspo5", "tags" : [ "morphology","Aponeurosis","Pennation","angle","length","Muscle","model","Fascicle","architecture" ], "intraHash" : "ed947ea3f941527dbb669066bc155938", "interHash" : "458e289e4840dfd9ef33052068cda6f6", "label" : "Architectural model for muscle growth during maturation.", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 1, "pub-type": "article", "journal": "Biomechanics and Modeling in Mechanobiology", "year": "2021", "url": "https://link.springer.com/article/10.1007/s10237-021-01492-y", "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "number": "20","pages": "2031\u20132044","abstract": "Muscle architecture, which includes parameters like fascicle length, pennation angle, and physiological cross-sectional area, strongly influences skeletal muscles' mechanical properties. During maturation, the muscle architecture has to adapt to a growing organism. This study aimed to develop an architectural model capable of predicting the complete 3D fascicle architecture for primarily unipennate muscles of an arbitrary age, based on fascicle data for an initial age. For model development, we collected novel data on 3D muscle architecture of the rabbit (Oryctolagus cuniculus) M. plantaris of eight animals ranging in age from 29 to 106 days. Experimental results show that plantaris muscle belly length increases by 73%, whereas mean fascicle length and mean pennation angle increases by 39 and 14%, respectively. Those changes were incorporated into the model. In addition to the data collected for M. plantaris the predictions of the model were compared to existing literature data of rabbit M. soleus and M. gastrocnemius medialis. With an error of −1.0\u2009±\u20098.6% for relative differences in aponeurosis length, aponeurosis width, muscle height, and muscle mass, the model delivered good results matching interindividual differences. For future studies, the model could be utilized to generate realistic architectural data sets for simulation studies.", "language" : "English", "doi" : "https://doi.org/10.1007/s10237-021-01492-y", "bibtexKey": "leichsenring2021architectural" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/23d83071c7cda47dc4505597be2791325/inspo5", "tags" : [ "morphology","Papenkort","length","Fascicle","Inspo","Pennation","Aponeurosis","angle","Muscle","model","Siebert","architecture" ], "intraHash" : "3d83071c7cda47dc4505597be2791325", "interHash" : "ec21172a48abe9631c89ebcb05ad0767", "label" : "Architectural model for muscle growth during maturation", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 1, "pub-type": "article", "journal": "Biomechanics and Modeling in Mechanobiology", "year": "2021", "url": "https://doi.org/10.1007/s10237-021-01492-y", "author": [ "Stefan Papenkort","Markus Boel","Tobias Siebert" ], "authors": [ {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Markus", "last" : "Boel"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "20","number": "5","pages": "2031--2044","abstract": "Muscle architecture, which includes parameters like fascicle length, pennation angle, and physiological cross-sectional area, strongly influences skeletal muscles' mechanical properties. During maturation, the muscle architecture has to adapt to a growing organism. This study aimed to develop an architectural model capable of predicting the complete 3D fascicle architecture for primarily unipennate muscles of an arbitrary age, based on fascicle data for an initial age. For model development, we collected novel data on 3D muscle architecture of the rabbit (Oryctolagus cuniculus) M. plantaris of eight animals ranging in age from 29 to 106 days. Experimental results show that plantaris muscle belly length increases by 73\\%, whereas mean fascicle length and mean pennation angle increases by 39 and 14\\%, respectively. Those changes were incorporated into the model. In addition to the data collected for M. plantaris the predictions of the model were compared to existing literature data of rabbit M. soleus and M. gastrocnemius medialis. With an error of −1.0þinspace±þinspace8.6\\% for relative differences in aponeurosis length, aponeurosis width, muscle height, and muscle mass, the model delivered good results matching interindividual differences. For future studies, the model could be utilized to generate realistic architectural data sets for simulation studies.", "issn" : "1617-7940", "doi" : "10.1007/s10237-021-01492-y", "bibtexKey": "Papenkort2021" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/28f1b8c3d34d6a835eb8d66fd42d347b9/inspo5", "tags" : [ "Angle","Aponeurosis","of","pennation","geometry","length","Muscle","growth","Fascicle","curvature" ], "intraHash" : "8f1b8c3d34d6a835eb8d66fd42d347b9", "interHash" : "a9c3211f5f0b44b9cf9a45aaa46cdb0a", "label" : "Three-dimensional architecture of rabbit M. soleus during growth", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 2, "pub-type": "article", "journal": "Journal of Biomechanics","publisher":"Elsevier BV", "year": "2020", "url": "https://doi.org/10.1016%2Fj.jbiomech.2020.110054", "author": [ "Stefan Papenkort","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "112","pages": "110054", "doi" : "10.1016/j.jbiomech.2020.110054", "bibtexKey": "Papenkort_2020" } ] }