@article{GschossmannSchedelSuessetal., author = {Gschoßmann, Lukas and Schedel, Valentin and S{\"u}ß, Franz and Weber, Markus and Pfingsten, Andrea and Dendorfer, Sebastian}, title = {Comparing kinematic and kinetic demands on the knee joint during selected physiotherapy exercises and activities of daily living}, series = {Technology and health care ; Special issue: BIOMDLORE}, journal = {Technology and health care ; Special issue: BIOMDLORE}, publisher = {Sage}, doi = {10.1177/09287329251413413}, pages = {14}, abstract = {Background: The knee is one of the most common areas to suffer injuries or be affected by surgery. Physiotherapy rehabilitation was shown to support recovery, but evidence guiding optimal rehabilitation practices is limited. To recommend appropriate exercises, it is essential to understand the musculoskeletal requirements involved in both physiotherapy and activities of daily living (ADLs).ObjectiveThis study aimed to evaluate and compare the knee joint kinematics, joint forces and muscle activity in knee flexors and extensors during selected rehabilitation exercises and ADLs.MethodsKinematic and kinetic data from 30 healthy participants were collected during 20 different tasks. Full-body musculoskeletal simulations were performed to estimate peak knee joint angles, angular velocities, joint reaction forces, and muscle activity of the knee flexors and extensors.ResultsComparatively high requirements were observed for lunges, squats, stair walking and gait. Medium requirements were observed for sitting down and rising from a chair. Low requirements were observed for balance shifts and variations of the single leg stand.ConclusionOverall, ADLs like gait and stair walking show surprisingly high requirements compared to many exercises employed in physiotherapy. These findings are a step towards biomechanically informed exercise selection and the development of personalized rehabilitation programs.}, language = {en} } @article{KrausKnipferJacobetal., author = {Kraus, Richard and Knipfer, Maximilian and Jacob, Matthias and Kienninger, Baerbel and Alikhani, Jasmine and Ghamsary, Parham Heydarzadeh and Reinker, Lukas and Adler, Ina and Dendorfer, Sebastian and Kieninger, Martin}, title = {Effectiveness and safety of techniques for cervical spine immobilization in mountain rescue}, series = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, volume = {34}, journal = {Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine}, publisher = {Springer}, doi = {10.1186/s13049-025-01530-z}, pages = {10}, abstract = {Background Cervical spine injuries in alpine sports require immediate immobilization at the site of the accident to avoid possible secondary damage caused by transportation. Using special sensor technology, this study investigated whether a cervical spine orthosis (cervical collar, Stifneck collar (Laerdal Medical GmbH, Puchheim, Germany)) provides greater stability than a vacuum mattress alone. Methods Using one male test person, we simulated transporting a patient with a spinal injury in steep alpine terrain. A wireless motion capture system (Xsens Technologies, Movella™ Inc., Henderson, USA) was used to record motion in three-dimensional space within a standardized environment. All tests were performed on a set course by the Bavarian Mountain Rescue Service. The test person lay on a mountain rescue stretcher and was immobilized with a vacuum mattress, either with or without a cervical orthosis. The axes of cervical spine movements were analyzed separately. Results There were no significant differences between immobilization with and without a cervical orthosis with regard to lateral flexion (max. 3.7° compared to 3.0°) in the frontal plane and maximum excursion in flexion (max. 1.6° compared to 2.8°) or extension (max. -1.6° compared to -1.7°). There was significantly greater rotation movement around the craniocaudal axis without an orthosis (max. 2.4° compared to 1.3°). Conclusion During mountain rescues, the cervical spine can be immobilized without a rigid cervical spine orthosis. Future research should explore the fundamental benefits of cervical spine immobilization, while the findings of this work contribute to the safe care of patients by avoiding the disadvantages associated with rigid cervical orthoses.}, language = {en} } @misc{GschossmannSchedelSuessetal., author = {Gschoßmann, Lukas and Schedel, Valentin and S{\"u}ß, Franz and Weber, Markus and Pfingsten, Andrea and Dendorfer, Sebastian}, title = {Evaluating Knee Joint Loads Across Exercises and Activities of Daily Living to Personalize TKA Rehabilitation}, series = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27.-31. July 2025, Stockholm}, journal = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27.-31. July 2025, Stockholm}, doi = {10.35096/othr/pub-8725}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87252}, pages = {1}, abstract = {This study assessed knee joint loading during various physiotherapy exercises and activities of daily living in 30 healthy subjects. Results showed that lunges and squats caused the highest joint forces, while gait and stair activities also imposed substantial loads. These findings support datadriven exercise selection for personalized rehabilitation after total knee arthroplasty.}, language = {en} } @misc{AdlerFoerstlČechovaetal., author = {Adler, Ina and F{\"o}rstl, Nikolas and Čechov{\´a}, Hana and Nov{\´a}ček, V{\´i}t and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Mechanistic analysis of pelvic floor functionality using musculoskeletal simulation}, series = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31 July 2025, Stockholm}, journal = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31 July 2025, Stockholm}, doi = {10.35096/othr/pub-8729}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-87294}, pages = {1}, abstract = {There is consensus that knowledge about the fundamentals of the pelvic floor remains incomplete, particularly regarding the sensitivity of individual pelvic floor muscles to posture variations. This study aimed to investigate the effects of variations in pelvic tilt and the point of force application induced by changes in posture on pelvic floor activity using musculoskeletal simulation. A parameter study analysed various loading cases, highlighting the coherent response of individual pelvic floor muscles to loads. Muscle activities and forces were compared across different force application points and pelvic tilt angles. A key finding was identifying peak muscle activity conditions that could help better understand the causes of pelvic floor disorders.}, language = {en} } @misc{BarthelSuessDendorfer, author = {Barthel, Mareike and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Predicting intra-abdominal pressure during walking and running}, series = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31. July 2025, Stockholm}, journal = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31. July 2025, Stockholm}, abstract = {Intra-abdominal pressure (IAP) is an important physiological parameter, which is difficult to measure during physical activity. In this study, motion capture, musculoskeletal modeling and a transformer encoder model are used to predict IAP during walking and running. The model showed promising results with an overall mean percentage error of 13.5\% and a Pearson correlation coefficient of 0.85. Minor challenges included the lower accuracy for fast walking and running and the limited amount of data. All in all, the prediction of IAP was successful, which opens up prospects for further applications.}, language = {en} } @misc{FoerstlAdlerSuessetal., author = {F{\"o}rstl, Nikolas and Adler, Ina and S{\"u}ß, Franz and Jansov{\´a}, Magdalena and Vychytil, Jan and Dendorfer, Sebastian}, title = {Evaluating the loads on the female pelvic floor during full-body activities using computational models}, abstract = {This work investigated the loads on the female pelvic floor during various full-body movements using computational models to calculate abdominal pressure and organ dynamic loads. While high-impact exercises resulted in higher loads, other movements showed lower loads, potentially indicating, which movements may be performed without risking pelvic floor overload and subsequent dysfunctions.}, language = {en} } @misc{SteinSchmitzKretschmeretal., author = {Stein, Leonhard and Schmitz, Paul and Kretschmer, Rainer and Dendorfer, Sebastian}, title = {Gait parameter based fall risk scoring}, abstract = {This study explored the connection between subjective self-assessed gait insecurities and objective movement scores. 93 subjects answered detailed fall risk questionnaires and performed functional tests. Significantly different movement patterns between fallers and non-fallers were found.}, language = {en} } @misc{GschossmannSuessDendorfer, author = {Gschoßmann, Lukas and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Impact of Model Parameters on Ground Reaction Force Predictions in Musculoskeletal Modelling}, series = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31 July, Stockholm}, journal = {ISB 2025 - The XXX Congress of the International Society of Biomechanics, 27-31 July, Stockholm}, abstract = {This study evaluated how model parameters affect ground reaction force (GRF) predictions in musculoskeletal simulations. A parameter study varying contact height and velocity thresholds and marker weights was conducted. While height and velocity thresholds had minimal impact, marker weights impact prediction errors. These findings highlight the importance of carefully selecting model parameters.}, language = {en} } @article{TroesterEcksteinKenneletal., author = {Tr{\"o}ster, Mark and Eckstein, Simon and Kennel, Paula and Kopp, Verna and Benkiser, Alina and Bihlmeier, Felicitas and Daub, Urban and Maufroy, Christophe and Dendorfer, Sebastian and Fritzsche, Lars and Schneider, Urs and Bauernhasl, Thomas}, title = {Person-specific evaluation method for occupational exoskeletons - Biomechanical body heat map}, series = {Applied Ergonomics}, volume = {132}, journal = {Applied Ergonomics}, publisher = {Elsevier}, doi = {10.1016/j.apergo.2025.104671}, pages = {30}, abstract = {Human-centred and ergonomic work design is one of the most important drivers for increasing the competitiveness of the European Union. As a flexible, person-specific occupational measure, exoskeletons promise great potential for effectively reducing individual ergonomic stress. Digital human models can provide important insights and offer great potential for systematising the effect and targeted use of exoskeletons, supporting their effective implementation in practice. In this article, digital human models are applied on two levels. Firstly, a realistic industrial logistics scenario in which boxes had to be relocated is designed with the help of a digital human model for workplace and process planning and secondly, a new biomechanical evaluation methodology to analyse intended and unintended effects on internal stress on the human body is demonstrated by applying musculoskeletal exoskeleton human models of four test subjects. Finally, the modelled biomechanical support tendencies of one exoskeleton are preliminary validated using EMG measurement data of the back muscles collected from the four male workers. The preliminary analysis of two back-support exoskeletons to demonstrate the new methodological approach confirms the expected, intended effects in the lower back and reveals unintended effects, such as e.g. changes in knee kinetics when applying a soft or hard-frame exoskeleton. Furthermore, the exemplary results to demonstrate the methodological approach expose notable differences between the test subjects, which underlines the relevance of person-specific evaluation and consideration of exoskeleton support. The preliminary validation shows a correlation between the modelled and the EMG-measured biomechanical exoskeleton support of the considered back muscles.}, language = {en} } @article{BarthelSuessDendorfer, author = {Barthel, Mareike and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Application of a transformer encoder for the prediction of intra-abdominal pressure}, series = {Computer Methods in Biomechanics and Biomedical Engineering}, journal = {Computer Methods in Biomechanics and Biomedical Engineering}, publisher = {Taylor \& Francis}, doi = {10.1080/10255842.2025.2586143}, pages = {11}, abstract = {Intra-abdominal pressure is a significant physiological parameter influencing spinal stability and pelvic floor health. This study investigates the potential of a transformer encoder model to predict IAP using motion capture data and musculoskeletal modeling. Data from 211 subjects performing walking, fast walking, and running were used to train a transformer encoder. The model showed promising results with an overall Mean Absolute Percentage Error of 13.5\% and a Pearson correlation coefficient of 0.85. Predictions for fast walking and running proved to be more challenging compared to walking, which was attributed to the greater variability and complexity of faster movements.}, language = {en} } @misc{PfingstenSchedelDendorferetal., author = {Pfingsten, Andrea and Schedel, Valentin and Dendorfer, Sebastian and Gschoßmann, Lukas}, title = {Biomechanical characteristics of knee rehabilitation exercises: a new approach for data-based exercise selection}, doi = {10.82161/v9a4-yt39}, pages = {8 min}, abstract = {Purpose: The principal objective of our research is to characterize key exercises that represent significant milestones in the rehabilitation process, employing biomechanical parameters to facilitate the distinction between stages of progression. Methods: We conducted an observational cross-sectional study on healthy volunteers (30 years), approved by an ethics committee. Subjects with a history of lower extremity disease were excluded. Movement data was collected, including the following hierarchy of exercise progressions: sit-to-stand-supported (STSS) - sit-to-stand (STS) - squat, stair climbing supported (SCS) - stair climbing (SC) - step-up, single-leg-stance-supported (SLSS) - single-leg-stance (SLS) - single-leg-stance-advanced (SLSA). Motion data was captured using a marker-less system (CapturyLive, v255, TheCaptury, Germany) and used for musculoskeletal simulations in the AnyBody Modeling System (v7.4.4, AnyBodyTechnology, Denmark) with a full-body model. ANOVA or Welch-Test with Bonferroni Post-Hoc was used to describe the anterior-posterior joint reaction force (JRF) normalized for body weight (BW) for each exercise. Positive values indicate an anterior JRF, and negative values a posterior JRF. Results: We recruited 31 subjects (female: 23/74.2\%) with a mean age of 22.81 years (SD:2.18). The analysis showed a significant difference in minimum JRF for STSS, STS, and squat (Welch-Test: F(2,56.421)=71.216, p0.001). Post-hoc analysis revealed that posterior JRF for STSS (mean:-2.63BW, SD:0.53) was lower than for STS (mean:-3.74BW, SD:0.42, p0.001), and STS was lower than squat (mean:-4.02BW, SD:0.35, p=0.043). No significant differences were observed in maximum JRF in the posterior direction (ANOVA: F(2,87)=1.151, p=0.324). For single-leg-stance exercises, the minimum JRF was similar for SLSS (mean:-0.34BW, SD:0.22) and SLS (mean:-0.55BW, SD:0.25, p=0.056), but higher in the posterior direction for SLSA (mean:-0.98BW, SD:0.49, p0.001; Welch-Test: F(2,54.379)=22.536, p0.001). Maximum JRF differences were also significant (ANOVA: F(2,87)=11.546, p0.001), with SLSS (mean:0.01BW, SD:0.22) showing a significant higher anterior JRF compared to SLS (mean:-0.16BW, SD:0.19, p=0.020). In the progression from SCS, SC to step-up, there was a significant difference in minimum JRF (ANOVA: F(2,87)=5.33, p=0.007), but not in maximum JRF (ANOVA: F(2,87)=0.624, p=0.538). SCS (mean:-3.42BW, SD:0.38) and SC (mean:-3.48BW, SD:0.54) showed no difference (p=1.000), but SC was significantly higher than step-up (mean:-3.58BW, SD:0.62, p=0.036). Conclusion(s): The exercises show differences in the JRF according to stages of progression, which can be taken into account when selecting exercises. Future research should address the group of patients who have undergone knee arthroplasty. Implications: In the future, it may be feasible to quantify patients' resilience based on sensor data and associate this with the optimal progression of an exercise sequence throughout the rehabilitation process.}, subject = {Physiotherapie}, language = {en} } @misc{Dendorfer, author = {Dendorfer, Sebastian}, title = {Towards a deeper understanding of Pelvic Floor Disorders via Biomechanical Models}, language = {en} } @misc{Dendorfer, author = {Dendorfer, Sebastian}, title = {Zahlen statt Meinung - virtuelle Ganzk{\"o}rpermodelle f{\"u}r die Mensch-Fahrzeug-Interaktion}, language = {de} } @misc{BrandtSteinhilberDendorferetal., author = {Brandt, Hanna and Steinhilber, Bernd and Dendorfer, Sebastian and Pfingsten, Andrea}, title = {Exoskelettale Unterst{\"u}tzung in der Pflege - eine Untersuchung der Muskelaktivit{\"a}t, des H{\"u}ftflexionswinkels und des subjektiven Belastungsempfinden bei einem simulierten Transfer.}, series = {Physioscience}, volume = {21}, journal = {Physioscience}, number = {S 01}, publisher = {Thieme}, doi = {10.1055/s-0045-1808226}, pages = {S61 -- S62}, abstract = {Die dargestellten Ergebnisse weisen darauf hin, dass das in der Studie verwendete passive r{\"u}ckenunterst{\"u}tzende Exoskelett die (wahrgenommene) k{\"o}rperliche Belastung beim dynamischen Transfer eines 45 kg schweren Dummys potenziell reduzieren kann und sich der maximale H{\"u}ftgelenksflexionswinkel mit Exo verkleinert. Dieses Ergebnis deckt sich mit bereits publizierten Studienergebnissen von Arbeitsaufgaben im Bereich des Hebens und Tragens von Gegenst{\"a}nden aus der Logistik}, language = {de} } @inproceedings{SchaefferSchmausserHerrmannetal., author = {Schaeffer, Leon and Schmaußer, Theresa and Herrmann, David and Lehmann, Lukas and Dendorfer, Sebastian and B{\"o}hm, Valter}, title = {Multi-Body Simulation of a Dynamic Hand Orthosis based on a Prestressed Compliant Structure Incorporating the Human Hand}, series = {2025 International Symposium on Medical Robotics (ISMR), May 14-16, 2025, Atlanta, GA, USA,}, booktitle = {2025 International Symposium on Medical Robotics (ISMR), May 14-16, 2025, Atlanta, GA, USA,}, publisher = {IEEE}, doi = {10.1109/ISMR67322.2025.11025982}, pages = {80 -- 86}, abstract = {Many dynamic hand orthoses use one degree of freedom joints, such as hinge joints. Therefore, these orthoses can only partially replicate the complex, multi-axis movement of the hand. A possible solution for this is the use of prestressed compliant structures as the basis for orthoses. Determining the joint forces in the wrist and optimizing the dynamic orthosis to influence these forces as well as acting muscle forces are important steps in the development of these orthoses. For this reason, in this work multi-body simulation models of an orthosis with human hand models are presented. Based on these theoretical investigations, more detailed orthosis models as well as initial prototypes of prestressed compliant dynamic hand orthoses can be developed.}, language = {en} } @article{RusavyCechovaDendorferetal., author = {Rusavy, Zdenek and Cechova, Hana and Dendorfer, Sebastian and Kalis, Vladimir and Ismail, Khaled M.}, title = {Is the Finnish grip tight enough? A manometric study of two manual perineal protection techniques}, series = {Acta Obstetricia et Gynecologica Scandinavica}, volume = {104}, journal = {Acta Obstetricia et Gynecologica Scandinavica}, number = {2}, publisher = {Wiley}, doi = {10.1111/aogs.15033}, pages = {423 -- 425}, language = {en} } @article{SchaefferHerrmannSchratzenstalleretal., author = {Schaeffer, Leon and Herrmann, David and Schratzenstaller, Thomas and Dendorfer, Sebastian and B{\"o}hm, Valter}, title = {Theoretical considerations on stiffness characteristics of a 3-dimensional tensegrity joint model for the use in dynamic hand orthoses}, series = {Journal of Medical Robotics Research}, journal = {Journal of Medical Robotics Research}, publisher = {World Scientific}, doi = {10.1142/S2424905X25400069}, language = {en} } @article{RusavyCechovaDendorferetal., author = {Rusavy, Zdenek and Cechova, Hana and Dendorfer, Sebastian and Kalis, Vladimir and Ismail, Khaled M.}, title = {Is the Finnish grip tight enough? A manometric study of two manual perineal protection techniques}, series = {Acta Obstetricia et Gynecologica Scandinavica}, journal = {Acta Obstetricia et Gynecologica Scandinavica}, edition = {Early view}, publisher = {Wiley}, doi = {10.1111/aogs.15033}, language = {en} } @article{KieningerSchneiderAueretal., author = {Kieninger, Martin and Schneider, Corinna and Auer, Simon and Reinker, Lukas and Adler, Ina and Dendorfer, Sebastian and Rosenberger, Johanna and Popp, Daniel and Eissnert, Christoph and Ludsteck, Dominik and Cyrus, Christopher and Hoffmann, Johannes and Morag, Sarah and Graf, Bernhard and Kieninger, B{\"a}rbel}, title = {Transport von schwer verletzten Traumapatienten im Rettungswagen mit und ohne starre Halsorthese: vergleichende biomechanische Messungen}, series = {Die Anaesthesiologie}, volume = {73}, journal = {Die Anaesthesiologie}, number = {10}, publisher = {Springer Nature}, doi = {10.1007/s00101-024-01462-w}, pages = {668 -- 675}, abstract = {Hintergrund: Der tats{\"a}chliche Stellenwert der pr{\"a}hospitalen Immobilisation der Halswirbels{\"a}ule (HWS) bei schwer verletzten Traumapatienten ist weiterhin unklar. In Anbetracht m{\"o}glicher negativer Implikationen durch das Anbringen einer starren HWS-Orthese muss deren Anwendung w{\"a}hrend der gesamten pr{\"a}hospitalen Phase kritisch hinterfragt werden. Ziel der Arbeit: Es sollten vergleichende biomechanische Messungen zur Beweglichkeit der HWS bei Immobilisation mittels Vakuummatratze mit und ohne zus{\"a}tzliches Anbringen einer starren HWS-Orthese nach Lagerung auf der Trage durchgef{\"u}hrt werden. Material und Methoden: Die Bewegungen der HWS beim Ein- und Ausladeprozess in einen modernen RTW sowie w{\"a}hrend der Fahrt entlang eines vordefinierten Parkours wurden mit einem Motion-Capture-System aufgezeichnet. Die Probandin, an der die Messungen durchgef{\"u}hrt wurden, wurde auf einer Vakuummatratze mit der M{\"o}glichkeit zur seitlichen Fixierung des Kopfes sowie Kinn- und Stirngurt auf einer elektrohydraulischen Fahrtrage immobilisiert. Bei der einen H{\"a}lfte der Versuche erfolgte die zus{\"a}tzliche Immobilisation der HWS mittels starrer Orthese, bei der anderen wurde auf die Anwendung einer HWS-Orthese verzichtet. Ergebnisse: Statistisch signifikante Unterschiede ergaben sich nur bei einigen biomechanischen Parametern in der sagittalen Ebene (Flexion und Extension). F{\"u}r die anderen Bewegungsrichtungen (axiale Rotation, laterale Beugung) wurden keine signifikanten Unterschiede f{\"u}r die gemessenen Parameter ermittelt. Generell wurden sowohl bei den Versuchen mit HWS-Orthese als auch ohne HWS-Orthese nur sehr geringe Winkelauslenkungen (im Mittel bei axialer Rotation und Flexion/Extension im Bereich von einem bis 2 Grad, bei der lateralen Beugung h{\"o}chstens 3 Grad) gemessen. Schlussfolgerung: Bei einer korrekt durchgef{\"u}hrten Immobilisation mittels einer Vakuummatratze mit der M{\"o}glichkeit zur seitlichen Stabilisierung des Kopfes sowie Kinn- und Stirngurt auf einer elektrohydraulischen Fahrtrage mit Beladesystem ergeben sich f{\"u}r den Ein- und Ausladeprozess sowie w{\"a}hrend der Fahrt in einem modernen RTW mit luftgefederter Tragenlagerung und Luftfederung der Hinterachse keine relevanten Vorteile bez{\"u}glich der Einschr{\"a}nkung der Bewegung der HWS durch die zus{\"a}tzliche Verwendung einer starren HWS-Orthese.}, language = {de} } @misc{Dendorfer, author = {Dendorfer, Sebastian}, title = {Sturz- und Frakturpr{\"a}vention: Use it or lose it!}, series = {10 Jahre Alterstraumatologie Caritas Krankenhaus St. Josef Regensburg}, journal = {10 Jahre Alterstraumatologie Caritas Krankenhaus St. Josef Regensburg}, language = {de} } @misc{GschossmannDendorfer, author = {Gschoßmann, Lukas and Dendorfer, Sebastian}, title = {Personalized Rehabilitation after Total Knee Arthroplasty}, series = {32nd Annual Meeting of the European Orthopaedic Research Society (EORS 2024), 18 - 20 September 2024, Aalborg}, journal = {32nd Annual Meeting of the European Orthopaedic Research Society (EORS 2024), 18 - 20 September 2024, Aalborg}, language = {en} } @misc{AdlerFoerstlSuessetal., author = {Adler, Ina and F{\"o}rstl, Nikolas and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Biomechanical exposition of the factors influencing the pelvic floor muscle activity}, series = {ESB 2024, 29th Congress of the European Society of Biomechanics, 30 June-3 July 2024, Edinburgh, Scotland}, journal = {ESB 2024, 29th Congress of the European Society of Biomechanics, 30 June-3 July 2024, Edinburgh, Scotland}, abstract = {Introduction About 40 \% of the women worldwide suffer from Pelvic Floor Dysfunctions [1]. In previous studies, musculoskeletal simulations helped to understand and facilitate the complex issues of musculoskeletal disorders in several different branches [2, 3]. A fundamental prerequisite for the generation of these models is to have a basic understanding of the stresses acting on the pelvic floor. The aim of this study is to investigate the biomechanical factors influencing the activity of the pelvic floor muscles by establishing a parameterised model. Methods To identify the factors that affect the pelvic floor muscles, the process is divided into several stages. The first step is to investigate the loads acting on the pelvic floor. For this, a simplified sagittal cross-sectional model of the upper body is analysed. The discretization of the abdominal cavity is presented with resulting force vectors representing the organs in the abdominal and pelvic region, the tensile force of the structures that fixate the organs as well as the intraabdominal pressure. A second step is the examination of the basic mechanics of the pelvic floor muscles. As the functional anatomy of these muscles demonstrate differences compared to other muscle groups [4], the understanding of how they differ is crucial for the construction of musculoskeletal models. After a static examination of loads on a simplified muscle model, an extended model including the physiological properties of a muscle must be involved in the considerations. Therefore, the influence of parameters such as the ideal muscle strength and fibre length, as well as elasticity or passive stiffness of the elements must be taken into account. The influencing factors of the variables can be analysed in a simplified pelvic floor muscle model by systematically changing the parameters. Results The process of analysing the factors influencing the activity of the pelvic floor muscles follows two main strategies. The review of the effects of the whole body identifies the forces acting on the pelvic floor muscles and effect their activity. With the examination of the basic mechanics of a simplified pelvic floor muscle model a better understanding is achieved of how the pelvic floor muscles absorb the loads acting in the body. Discussion This process results in the main influence factors on the activity of the pelvic floor. The consequent parameters form the basis for a biomechanically justified construction of musculoskeletal simulation models of the pelvic floor. Nevertheless, it must be considered, that these mechanical studies represent simplifications of the reality. References 1. Wang et al, Front Public Health, 10:975829, 2022. 2. Bulat et al., Curr Sports Med Rep, 18(6):210-216, 2019 3. Melzner et al., Eur J Obstet Gynecol Reprod Biol, 264:306-313, 2021 4. Ashton-Miller et al., Ann N Y Acad Sci, 1101:266-96, 2007}, language = {en} } @misc{FoerstlAdlerSuessetal., author = {F{\"o}rstl, Nikolas and Adler, Ina and Suess, Franz and Čechov{\´a}, Hana and Jansov{\´a}, Magdalena and Cimrman, Robert and Vychytil, Jan and Dendorfer, Sebastian}, title = {Workflow for the development of a non-invasive feedback device to assess pelvic floor contractions}, series = {ESB 2024, 29th Congress of the European Society of Biomechanics, 30 June-3 July 2024, Edinburgh, Scotland}, journal = {ESB 2024, 29th Congress of the European Society of Biomechanics, 30 June-3 July 2024, Edinburgh, Scotland}, abstract = {Introduction Pelvic floor disorders affect about 40\% of women worldwide [1]. Pelvic floor muscle (PFM) training is both a preventive and a therapeutic intervention. Current PFM training devices are invasive and have little scientific evidence. The idea is to develop a noninvasive feedback device to assess adequate PFM contraction. Therefore, evidence-based female musculoskeletal models, non-invasive data acquisition, sensor technology and artificial intelligence (AI) will be combined. This work presents the workflow to achieve such a feedback device and describes the interaction of the technologies used. Methods Exercises that induce PFM contractions have been evaluated and defined. Motion capture of these exercises will provide input for female musculoskeletal models. A combination of biomechanical rigid body and FEM simulations will be used to estimate PFM contractions. In addition, a non-invasive sensor will measure pelvic floor activity. The simulated and measured data will be used to develop an AI model that provides feedback on PFM contractions based on non-invasive data collection. Results The AMMR (AnyBody Managed Model Repository) of the AnyBody modelling system (AMS, Aalborg, Denmark) serves as the initial model for performing inverse dynamic simulations of the exercises. To calculate the PFM forces, the full-body model must be supplemented with the relevant pelvic floor structures and a mass model of the internal organs. A modified abdominal pressure model must also be incorporated. The AMS calculates the PFM activities caused by the internal organ loads and the generated abdominal pressure during the exercises. The muscle activities are transferred to a FEM model of the female pelvic floor (SfePy, simple finite elements in Python). The identical pelvic floor structures were integrated into the FEM model as in the AMS. Active PFM contractions can be simulated using the FEM model. Movement of the coccyx due to PFM contractions has been reported in the literature [2,3]. Therefore, a noninvasive coccyx motion sensor will be developed to provide additional information on PFM contractions. The measured data (coccyx motion sensor, motion capture) and the simulation results of the models will be combined to create an AI feedback model using Python. The final feedback device will consist of the AI model and the developed coccyx motion sensor, which can reproduce the resulting PFM contractions based on the sensor data and simplified motion tracking. Discussion The creation of the AMS and the FEM model is a prerequisite for the development of the feedback device. The relevant structures in the models are located inside the body. This limits the ability to observe the structures during the exercises, which can lead to difficulties in model validation. The development of a user-friendly sensor with sufficient measuring accuracy of the coccyx motion is another challenge. Nevertheless, the workflow represents a promising approach to develop a noninvasive feedback system to assess PFM contraction. References 1. Wang et al, Front Public Health, 10:975829, 2022. 2. B{\o} et al, Neurourol Urodyn, 20:167-174, 2001. 3. Fujisaki et al, J Phys Ther Sci, 30:544-548, 2018. Acknowledgements This work was supported by the project no. BYCZ01-014 of the Program INTERREG Bavaria - Czechia 2021-2027.}, language = {en} }