TY - JOUR A1 - Werkhausen, Amelie A1 - Cronin, Neil J. A1 - Albracht, Kirsten A1 - Bojsen-Møller, Jens A1 - Seynnes, Olivier R. T1 - Distinct muscle-tendon interaction during running at different speeds and in different loading conditions JF - Journal of Applied Physiology Y1 - 2019 U6 - https://doi.org/10.1152/japplphysiol.00710.2018 SN - 1522-1601 VL - 127 IS - 1 SP - 246 EP - 253 ER - TY - JOUR A1 - Werkhausen, Amelie A1 - Cronin, Neil J. A1 - Albracht, Kirsten A1 - Paulsen, Gøran A1 - Larsen, Askild V. A1 - Bojsen-Møller, Jens A1 - Seynnes, Olivier R. T1 - Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running JF - PeerJ N2 - Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric singleleg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18% (P <0:01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30% (P <0:01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple inseries models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running. KW - Achilles tendon KW - Stiffness KW - Running KW - Tendon properties KW - Architectural gear ratio Y1 - 2019 U6 - https://doi.org/10.7717/peerj.6764 SN - 21678359 PB - Peer CY - London ER - TY - JOUR A1 - Werkhausen, Amelie A1 - Willwacher, Steffen A1 - Albracht, Kirsten T1 - Medial gastrocnemius muscle fascicles shorten throughout stance during sprint acceleration JF - Scandinavian Journal of Medicine & Science in Sports N2 - The compliant nature of distal limb muscle-tendon units is traditionally considered suboptimal in explosive movements when positive joint work is required. However, during accelerative running, ankle joint net mechanical work is positive. Therefore, this study aims to investigate how plantar flexor muscle-tendon behavior is modulated during fast accelerations. Eleven female sprinters performed maximum sprint accelerations from starting blocks, while gastrocnemius muscle fascicle lengths were estimated using ultrasonography. We combined motion analysis and ground reaction force measurements to assess lower limb joint kinematics and kinetics, and to estimate gastrocnemius muscle-tendon unit length during the first two acceleration steps. Outcome variables were resampled to the stance phase and averaged across three to five trials. Relevant scalars were extracted and analyzed using one-sample and two-sample t-tests, and vector trajectories were compared using statistical parametric mapping. We found that an uncoupling of muscle fascicle behavior from muscle-tendon unit behavior is effectively used to produce net positive mechanical work at the joint during maximum sprint acceleration. Muscle fascicles shortened throughout the first and second steps, while shortening occurred earlier during the first step, where negative joint work was lower compared with the second step. Elastic strain energy may be stored during dorsiflexion after touchdown since fascicles did not lengthen at the same time to dissipate energy. Thus, net positive work generation is accommodated by the reuse of elastic strain energy along with positive gastrocnemius fascicle work. Our results show a mechanism of how muscles with high in-series compliance can contribute to net positive joint work. KW - locomotion KW - muscle mechanics KW - running KW - sprint start KW - ultrasonography Y1 - 2021 U6 - https://doi.org/10.1111/sms.13956 SN - 0905-7188 (Druckausgabe) SN - 1600-0838 (Onlineausgabe) VL - 31 IS - 7 SP - 1471 EP - 1480 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Wiescher, A. A1 - Kotliar, Konstantin A1 - Neuhann, T. A1 - Lanzl, Ines M. T1 - Rasch progrediente Visusminderung beider Augen bei einem jungen Patienten JF - Der Ophthalmologe N2 - Ein 34-jähriger männlicher Patient stellte sich zur Abklärung einer seit dem 9. Lebensjahr bestehenden und im letzten Jahr rasch progredienten Visusminderung beider Augen bei uns vor. Er beschrieb eine subjektiv zunehmende, im Spiegel für ihn selbst sichtbare, weißliche Trübung in der Pupille beidseits und eine starke Blendempfindlichkeit. Nebenbefundlich gab er rezidivierende Konjunktivitiden und morgens verklebte Lider an. Eine Allergie auf Gräserpollen und eine Unverträglichkeit auf Alkohol sowie mehrere Lebensmittel seien ebenfalls bekannt. Zusätzlich leidet der Patient an stark ausgeprägtem atopischem Ekzem. Dieses wurde nie systemisch, sondern nur bei Bedarf mit kortisonhaltiger Salbe therapiert. Y1 - 2010 U6 - https://doi.org/10.1007/s00347-007-1586-x SN - 1433-0423 VL - 105 IS - 4 SP - 389 EP - 392 PB - Springer CY - Berlin ER - TY - JOUR A1 - Yang, Peng-Fei A1 - Kriechbaumer, Andreas A1 - Albracht, Kirsten A1 - Sanno, Maximilian A1 - Ganse, Bergita A1 - Koy, Timmo A1 - Shang, Peng A1 - Brüggemann, Gert-Peter A1 - Müller, Lars Peter A1 - Rittweger, Jörn T1 - On the relationship between tibia torsional deformation and regional muscle contractions in habitual human exercises in vivo JF - Journal of Biomechanics Y1 - 2015 U6 - https://doi.org/10.1016/j.jbiomech.2014.12.031 SN - 0021-9290 VL - 48 IS - 3 SP - 456 EP - 464 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Yang, Peng-Fei A1 - Kriechbaumer, Andreas A1 - Albracht, Kirsten A1 - Sanno, Maximilian A1 - Ganse, Bergita A1 - Koy, Timmo A1 - Shang, Peng A1 - brüggemann, Gert-Peter A1 - Müller, Lars Peter A1 - Rittweger, Jörn T1 - A novel optical approach for assessing in vivo bone segment deformation and its application in muscle-bone relationship studies in humans JF - Journal of Orthopaedic Translation Y1 - 2014 U6 - https://doi.org/10.1016/j.jot.2014.07.078 SN - 2214-0328 SN - 2214-031X VL - 2 IS - 4 SP - 238 EP - 238 PB - Elsevier CY - Singapore ER - TY - JOUR A1 - Zange, Jochen A1 - Schopen, Kathrin A1 - Albracht, Kirsten A1 - Gerlach, Darius A. A1 - Frings-Meuthen, Petra A1 - Maffiuletti, Nicola A. A1 - Bloch, Wilhelm A1 - Rittweger, Jörn T1 - Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial JF - Plos one Y1 - 2017 U6 - https://doi.org/10.1371/journal.pone.0171562 VL - 12 IS - 2 ER - TY - JOUR A1 - Zerlin, Kay A1 - Digel, Ilya A1 - Stadler, Andreas M. A1 - Büldt, Georg A1 - Zaccai, Guiseppe A1 - Artmann, Gerhard T1 - Dynamics and interactions of hemoglobin in human red blood cells and concentrated hemoglobin solutions JF - Regenerative medicine. 2 (2007), H. 5 Y1 - 2007 SN - 1746-0751 N1 - Proceedings of the 3rd World Congress on Regenerative Medicine. October 18-20, 2007. Leipzig, Germany SP - 573 EP - 573 ER - TY - JOUR A1 - Zerlin, Kay A1 - Kasischke, Nicole A1 - Digel, Ilya A1 - Maggakis-Kelemen, Christina A1 - Temiz Artmann, Aysegül A1 - Porst, Dariusz A1 - Kayser, Peter A1 - Linder, Peter A1 - Artmann, Gerhard T1 - Structural transition temperature of hemoglobins correlates with species’ body temperature JF - European Biophysics Journal. 37 (2007), H. 1 Y1 - 2007 SN - 1432-1017 SP - 1 EP - 10 ER - TY - JOUR A1 - Zhantlessova, Sirina A1 - Savitskaya, Irina A1 - Kistaubayeva, Aida A1 - Ignatova, Ludmila A1 - Talipova, Aizhan A1 - Pogrebnjak, Alexander A1 - Digel, Ilya T1 - Advanced “Green” prebiotic composite of bacterial cellulose/pullulan based on synthetic biology-powered microbial coculture strategy JF - Polymers N2 - Bacterial cellulose (BC) is a biopolymer produced by different microorganisms, but in biotechnological practice, Komagataeibacter xylinus is used. The micro- and nanofibrillar structure of BC, which forms many different-sized pores, creates prerequisites for the introduction of other polymers into it, including those synthesized by other microorganisms. The study aims to develop a cocultivation system of BC and prebiotic producers to obtain BC-based composite material with prebiotic activity. In this study, pullulan (PUL) was found to stimulate the growth of the probiotic strain Lactobacillus rhamnosus GG better than the other microbial polysaccharides gellan and xanthan. BC/PUL biocomposite with prebiotic properties was obtained by cocultivation of Komagataeibacter xylinus and Aureobasidium pullulans, BC and PUL producers respectively, on molasses medium. The inclusion of PUL in BC is proved gravimetrically by scanning electron microscopy and by Fourier transformed infrared spectroscopy. Cocultivation demonstrated a composite effect on the aggregation and binding of BC fibers, which led to a significant improvement in mechanical properties. The developed approach for “grafting” of prebiotic activity on BC allows preparation of environmentally friendly composites of better quality. KW - coculture KW - pullulan KW - exopolysaccharides KW - prebiotic KW - bacterial cellulose Y1 - 2022 U6 - https://doi.org/10.3390/polym14153224 SN - 2073-4360 N1 - This article belongs to the Special Issue "Cellulose Based Composites" VL - 14 IS - 15 PB - MDPI CY - Basel ER -