{ "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/295af4cf87ffa1c7f150a05deb8bb810d/inspo5", "tags" : [ "bladder","material","adaptation","biological","urinary","contraction","tissue","free","soft","properties" ], "intraHash" : "95af4cf87ffa1c7f150a05deb8bb810d", "interHash" : "ad5f2b6a3128f8eb0f36ab2826d465bb", "label" : "Shaping Smooth Muscle Forces: The Role of Preconditioning in Urinary Smooth Muscle", "user" : "inspo5", "description" : "", "date" : "2026-03-10 11:32:12", "changeDate" : "2026-03-10 11:32:12", "count" : 1, "pub-type": "article", "journal": "Journal of Applied Physiology","publisher":"American Physiological Society", "year": "2026", "url": "http://dx.doi.org/10.1152/japplphysiol.00782.2025", "author": [ "Simon Kiem","Stefan Papenkort","Mischa Borsdorf","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Simon", "last" : "Kiem"}, {"first" : "Stefan", "last" : "Papenkort"}, {"first" : "Mischa", "last" : "Borsdorf"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "abstract": "Smooth muscle (SM) exhibits rapid mechanical adaptation in response to various stimuli, posing challenges for reproducible experimental results and consistent material parameter determination in biomechanical modeling. Preconditioning involving repeated loading and unloading cycles are commonly used to stabilize mechanical responses prior to testing. However, their influence on tissue properties and data variability remains underexplored. This study compares the effects of three preconditioning routines \u2013 passive cycling (PCYC), no preconditioning (PNPC), and free contraction (PFC) \u2013 on the active and passive force responses of porcine urinary bladder (UB) SM tissue. Three tissue strips from 12 UBs were randomly assigned to one of the routines and underwent an identical protocol involving a passive stretch ramp and two isometric contractions (IC1, IC2) to evaluate active and passive force development. After PCYC, the tissue generated the highest active (IC2: 44.7 ± 29.4 kPa) and passive tensions (IC2: 5.6 ± 4.3 kPa), though it also showed the highest variance in active tension. PNPC resulted in the lowest variance in active tension with a coefficient of variation (CV) of 45%, and PFC showed the lowest variance in passive tension, CV = 57%. These findings imply that the decision for a certain preconditioning protocol influences the observed mechanical properties. In this context, PFC appears promising for minimizing passive force variability and preventing creep-induced lengthening. This could offer a more reliable foundation for subsequent experiments analyzing mechanical parameters. This study underscores the importance of customized preconditioning strategies to enhance consistency and comparability in SM research and organ modeling.", "language" : "English", "issn" : "1522-1601", "preprinturl" : "https://journals.physiology.org/doi/abs/10.1152/japplphysiol.00782.2025", "doi" : "10.1152/japplphysiol.00782.2025", "bibtexKey": "Kiem_2026" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/20b8a2822ba7baaca10669289c107bd9c/inspo5", "tags" : [ "dynamics","muscle","work","mechanical","damping","intrinsic","stiffness","properties" ], "intraHash" : "0b8a2822ba7baaca10669289c107bd9c", "interHash" : "a826d07e2f8c83bb1b8a903cbbcccde6", "label" : "Muscle preflex response to perturbations in locomotion: In vitro experiments and simulations with realistic boundary conditions", "user" : "inspo5", "description" : "", "date" : "2023-05-16 10:24:04", "changeDate" : "2023-05-16 10:24:04", "count" : 1, "pub-type": "article", "journal": "Frontiers in Bioengineering and Biotechnology", "year": "2023", "url": "https://www.frontiersin.org/articles/10.3389/fbioe.2023.1143926/full", "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "11","abstract": "Musculoskeletal disorders (MSD) are a widespread problem, often regarding the lumbar region. Exoskeletons designed to support the lower back could be used in physically demanding professions with the intention of reducing the strain on the musculoskeletal system, e.g., by lowering task-related muscle activation. The present study aims to investigate the effect of an active exoskeleton on back muscle activity when lifting weights. Within the framework of the study, 14 subjects were asked to lift a 15 kg box with and without an active exoskeleton which allows the adjustment of different levels of support, while the activity of their M. erector spinae (MES) was measured using surface electromyography. Additionally, the subjects were asked about their overall rating of perceived exertion (RPE) during lifting under various conditions. Using the exoskeleton with the maximum level of support, the muscle activity was significantly lower than without exoskeleton. A significant correlation was found between the exoskeleton\u2019s support level and the reduction of MES activity. The higher the support level, the lower the observed muscle activity. Furthermore, when lifting with the maximum level of support, RPE was found to be significantly lower than without exoskeleton too. A reduction in the MES activity indicates actual support for the movement task and might indicate lower compression forces in the lumbar region. It is concluded that the active exoskeleton supports people noticeably when lifting heavy weights. Exoskeletons seem to be a powerful tool for reducing load during physically demanding jobs and thus, their use might be helpful in lowering the risk of MSD.", "language" : "English", "doi" : "10.3389/fbioe.2023.1143926", "bibtexKey": "siebert2023muscle" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2529e2a96561412f7c16f2c7875622058/elkepeter", "tags" : [ "Lienstromberg","IADM","systems","microelectromechanical","qualitative","solutions","of","to","properties" ], "intraHash" : "529e2a96561412f7c16f2c7875622058", "interHash" : "462824bdb76c7d72e72898a1d2d0dc02", "label" : "On qualitative properties of solutions to microelectromechanical systems with general permittivity", "user" : "elkepeter", "description" : "", "date" : "2023-03-27 11:14:19", "changeDate" : "2023-04-03 07:21:33", "count" : 4, "pub-type": "article", "journal": "Monatsh. Math.", "year": "2016", "url": "https://doi.org/10.1007/s00605-015-0744-5", "author": [ "Christina Lienstromberg" ], "authors": [ {"first" : "Christina", "last" : "Lienstromberg"} ], "volume": "179","number": "4","pages": "581--602","abstract": "\"Qualitative properties of solutions to the evolution problem modelling microelectromechanical systems with general permittivity profile are investigated. The system couples a parabolic evolution problem for the displacement of a membrane with an elliptic free boundary value problem for the electric potential in the region between the membrane and a rigid ground plate. We briefly allude to results concerning local and global well-posedness and the small-apect ratio limit. However, the focus is here on proving non-positivity of the membrane displacement for the full moving boundary problem under certain boundary conditions on the potential, as well as the existence of finite-time singularities assuming to have a non-positive solution.''", "mrclass" : "35R35 (35B09 35B44 35Q74 74M05)", "fjournal" : "Monatshefte für Mathematik", "mrnumber" : "3474882", "issn" : "0026-9255", "doi" : "10.1007/s00605-015-0744-5", "bibtexKey": "MR3474882" } , { "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/2c5478835f2cd88ec490ace0e656a5b8f/inspo5", "tags" : [ "gastric","relation","tissue","enhancement","force-velocity","contraction-behavior","muscle","motility","depression","force","smooth","force-length","properties" ], "intraHash" : "c5478835f2cd88ec490ace0e656a5b8f", "interHash" : "a5eeda529640c3525644d1772eb0cba6", "label" : "Porcine Stomach Smooth Muscle Force Depends on History-Effects", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:14:49", "count" : 2, "pub-type": "article", "journal": "Front Physiol", "year": "2017", "url": "https://www.ncbi.nlm.nih.gov/pubmed/29093684", "author": [ "A. Tomalka","M. Borsdorf","M. Böl","T. Siebert" ], "authors": [ {"first" : "A.", "last" : "Tomalka"}, {"first" : "M.", "last" : "Borsdorf"}, {"first" : "M.", "last" : "Böl"}, {"first" : "T.", "last" : "Siebert"} ], "volume": "8","pages": "802","abstract": "The stomach serves as food reservoir, mixing organ and absorption area for certain substances, while continually varying its position and size. Large dimensional changes during ingestion and gastric emptying of the stomach are associated with large changes in smooth muscle length. These length changes might induce history-effects, namely force depression (FD) following active muscle shortening and force enhancement (FE) following active muscle stretch. Both effects have impact on the force generating capacity of the stomach, and thus functional relevance. However, less is known about history-effects and active smooth muscle properties of stomach smooth muscle. Thus, the aim of this study was to investigate biomechanical muscle properties as force-length and force-velocity relations (FVR) of porcine stomach smooth muscle strips, extended by the analysis of history-effects on smooth muscle force. Therefore, in total n = 54 tissue strips were dissected in longitudinal direction from the ventral fundus of porcine stomachs. Different isometric, isotonic, and isokinetic contraction protocols were performed during electrical muscle stimulation. Cross-sectional areas (CSA) of smooth muscles were determined from cryo-histological sections stained with Picrosirius Red. Results revealed that maximum smooth muscle tension was 10.4 ± 2.6 N/cm2. Maximum shortening velocity (Vmax ) and curvature factor (curv) of the FVR were 0.04 ± 0.01 [optimum muscle length/s] and 0.36 ± 0.15, respectively. The findings of the present study demonstrated significant (P < 0.05) FD [up to 32% maximum muscle force (Fim )] and FE (up to 16% Fim ) of gastric muscle tissue, respectively. The FE- and FD-values increased with increasing ramp amplitude. This outstanding muscle behavior is not accounted for in existing models so far and strongly supports the idea of a holistic reflection of distinct stomach structure and function. For the first time this study provides a comprehensive set of stomach smooth muscle parameters including classic biomechanical muscle properties and history-dependent effects, offering the possibility for the development and validation of computational stomach models. Furthermore, this data set facilitates novel insights in gastric motility and contraction behavior based on the re-evaluation of existing contractile mechanisms. That will likely help to understand physiological functions or dysfunctions in terms of gastric accommodation and emptying.", "issn" : "1664-042X (Print)\r\n1664-042X (Linking)", "doi" : "10.3389/fphys.2017.00802", "bibtexKey": "RN6295" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/20e9dbe076502380e2b8e70a80da95818/inspo5", "tags" : [ "Semi-confined","Soleus","tissue","characteristics","cuniculus","Microstructural","Axial","tests","Age-dependent","Inspo","muscle","Oryctolagus","Morphometry","Siebert","compression","properties" ], "intraHash" : "0e9dbe076502380e2b8e70a80da95818", "interHash" : "6afbb85807dbc73f3599b68ac7ec0018", "label" : "Age-dependent mechanical and microstructural properties of the rabbit soleus muscle", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 1, "pub-type": "article", "journal": "Acta Biomaterialia","publisher":"Elsevier BV", "year": "2021", "url": "https://doi.org/10.1016%2Fj.actbio.2021.07.066", "author": [ "Kay Leichsenring","Asha Viswanathan","Steven Kutschke","Markus Siebert, TobiasBöl" ], "authors": [ {"first" : "Kay", "last" : "Leichsenring"}, {"first" : "Asha", "last" : "Viswanathan"}, {"first" : "Steven", "last" : "Kutschke"}, {"first" : "Markus", "last" : "Siebert, TobiasBöl"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "134","pages": "453--465","abstract": "During growth there are serious changes in the skeletal muscles to compensate for the changed requirements in terms of body weight and size. In this study, the age-dependent (between 21 and 100 days) mechanical and microstructural properties of rabbit soleus muscle tissue were investigated. For this purpose, morphological properties (animal mass, soleus muscle mass, tibial length) were measured at 5 different times during aging. On the other hand, fibre orientation-dependent axial and semi-confined compression experiments were realised. In addition, the essential components (muscle fibres, extracellular matrix, remaining components), dominating the microstructure of muscle tissue, were analysed. While the mechanical results show hardly any age-dependent differences, the morphological and microstructural results show clear age-dependent differences. All morphological parameters increase significantly (animal mass by 839.2%, muscle mass 1050.6%, tibial length 233.6%). In contrast, microstructural parameters change differently. The percentage of fibres (divided into slow-twitch (ST) and fast-twitch (FT) fibres) increases significantly (137.6%), while the proportions of the extracellular matrix and the remaining components (48.2% and 46.1%) decrease. At the same time, the cross-sectional area of the fibres increases significantly (697.9%). The totality of this age-dependent information provides a deeper understanding of age-related changes in muscle structure and function and may contribute to successful development and validation of growth models in the future.\n\nStatement of significance\nThis article reports the first comprehensive data set on age-dependent morphological (animal mass, soleus muscle mass, tibial length), mechanical (axial and semi-confined compression), and microstructural (muscle fibres, extracellular matrix, remaining components) properties of the rabbit soleus muscle. On the one hand, the results of this study contribute to the understanding of muscle mechanics and thus to understanding of load transfer mechanisms inside the muscle tissue during growth. On the other hand, these results are relevant to the fields of constitutive formulation of age-dependent muscle tissue.", "doi" : "10.1016/j.actbio.2021.07.066", "bibtexKey": "Leichsenring_2021" } ] }