TY - JOUR A1 - Sousa, Marcos A. M. A1 - Siqueira, Jose R. Jr. A1 - Vercik, Andres A1 - Schöning, Michael Josef A1 - Oliveira, Osvaldo N. Jr. T1 - Determining the optimized layer-by-layer film architecture with dendrimer/carbon nanotubes for field-effect sensors JF - IEEE Sensors Journal N2 - The capacitive electrolyte–insulator–semiconductor (EIS) structure is a typical device based on a field-effect sensor platform. With a simple silicon-based structure, EIS have been useful for several sensing applications, especially with incorporation of nanostructured films to modulate the ionic transport and the flat-band potential. In this paper, we report on ion transport and changes in flat-band potential in EIS sensors made with layer-by-layer films containing poly(amidoamine) (PAMAM) dendrimer and single-walled carbon nanotubes (SWNTs) adsorbed on p-Si/SiO 2 /Ta 2 O 5 chips with an Al ohmic contact. The impedance spectra were fitted using an equivalent circuit model, from which we could determine parameters such as the double-layer capacitance. This capacitance decreased with the number of bilayers owing to space charge accumulated at the electrolyte–insulator interface, up to three PAMAM/SWNTs bilayers, after which it stabilized. The charge-transfer resistance was also minimum for three bilayers, thus indicating that this is the ideal architecture for an optimized EIS performance. The understanding of the influence of nanostructures and the fine control of operation parameters pave the way for optimizing the design and performance of new EIS sensors. Y1 - 2017 U6 - http://dx.doi.org/10.1109/JSEN.2017.2653238 SN - 1558-1748 VL - 17 IS - 6 SP - 1735 EP - 1740 PB - IEEE CY - New York ER - TY - JOUR A1 - Gamella, Maria A1 - Zakharchenko, Andrey A1 - Guz, Nataliia A1 - Masi, Madeline A1 - Minko, Sergiy A1 - Kolpashchikov, Dmitry M. A1 - Iken, Heiko A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - DNA computing system activated by electrochemically triggered DNA realease from a polymer-brush-modified electrode array JF - Electroanalysis N2 - An array of four independently wired indium tin oxide (ITO) electrodes was used for electrochemically stimulated DNA release and activation of DNA-based Identity, AND and XOR logic gates. Single-stranded DNA molecules were loaded on the mixed poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA)/poly(methacrylic acid) (PMAA) brush covalently attached to the ITO electrodes. The DNA deposition was performed at pH 5.0 when the polymer brush is positively charged due to protonation of tertiary amino groups in PDMAEMA, thus resulting in electrostatic attraction of the negatively charged DNA. By applying electrolysis at −1.0 V(vs. Ag/AgCl reference) electrochemical oxygen reduction resulted in the consumption of hydrogen ions and local pH increase near the electrode surface. The process resulted in recharging the polymer brush to the negative state due to dissociation of carboxylic groups of PMAA, thus repulsing the negatively charged DNA and releasing it from the electrode surface. The DNA release was performed in various combinations from different electrodes in the array assembly. The released DNA operated as input signals for activation of the Boolean logic gates. The developed system represents a step forward in DNA computing, combining for the first time DNA chemical processes with electronic input signals. Y1 - 2017 U6 - http://dx.doi.org/10.1002/elan.201600389 SN - 1521-4109 VL - 29 IS - 2 SP - 398 EP - 408 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Bronder, Thomas A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Label-free detection of double-stranded DNA molecules with polyelectrolyte-modified capacitive field-effect sensors T1 - Markierungsfreie Detektion doppelsträngiger DNA Moleküle mit Hilfe von Polyelektrolyt-modifizierten kapazitiven Feldeffekt-Sensoren JF - tm - Technisches Messen N2 - In this study, polyelectrolyte-modified field-effect-based electrolyte-insulator-semiconductor (EIS) devices have been used for the label-free electrical detection of double-stranded deoxyribonucleic acid (dsDNA)molecules. The sensor-chip functionalization with a positively charged polyelectrolyte layer provides the possibility of direct adsorptive binding of negatively charged target DNA oligonucleotides onto theSiO2-chip surface.EIS sensors can be utilized as a tool to detect surface-charge changes; the electrostatic adsorption of oligonucleotides onto the polyelectrolyte layer leads to a measureable surface-potential change. Signals of 39mV have been recorded after the incubation with the oligonucleotide solution. Besides the electrochemical experiments, the successful adsorption of dsDNA onto the polyelectrolyte layer has been verified via fluorescence microscopy. The presented results demonstrate that the signal recording of EISchips, which are modified with a polyelectrolyte layer, canbe used as a favorable approach for a fast, cheap and simple detection method for dsDNA. Y1 - 2017 U6 - http://dx.doi.org/10.1515/teme-2017-0015 VL - 84 IS - 10 SP - 628 EP - 634 PB - De Gruyter CY - Oldenbourg ER - TY - JOUR A1 - Arreola, Julio A1 - Oberländer, Jan A1 - Mätzkow, M. A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Surface functionalization for spore-based biosensors with organosilanes JF - Electrochimica Acta N2 - In the present work, surface functionalization of different sensor materials was studied. Organosilanes are well known to serve as coupling agent for biomolecules or cells on inorganic materials. 3-aminopropyltriethoxysilane (APTES) was used to attach microbiological spores time to an interdigitated sensor surface. The functionality and physical properties of APTES were studied on isolated sensor materials, namely silicon dioxide (SiO2) and platinum (Pt) as well as the combined material on sensor level. A predominant immobilization of spores could be demonstrated on SiO2 surfaces. Additionally, the impedance signal of APTES-functionalized biosensor chips has been investigated. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.electacta.2017.04.157 SN - 0013-4686 VL - 241 SP - 237 EP - 243 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ciritsis, Alexander A1 - Horbach, Andreas A1 - Staat, Manfred A1 - Kuhl, Christiane K. A1 - Kraemer, Nils Andreas T1 - Porosity and tissue integration of elastic mesh implants evaluated in vitro and in vivo JF - Journal of Biomedical Materials Research: Part B: Applied Biomaterials N2 - Purpose In vivo, a loss of mesh porosity triggers scar tissue formation and restricts functionality. The purpose of this study was to evaluate the properties and configuration changes as mesh deformation and mesh shrinkage of a soft mesh implant compared with a conventional stiff mesh implant in vitro and in a porcine model. Material and Methods Tensile tests and digital image correlation were used to determine the textile porosity for both mesh types in vitro. A group of three pigs each were treated with magnetic resonance imaging (MRI) visible conventional stiff polyvinylidene fluoride meshes (PVDF) or with soft thermoplastic polyurethane meshes (TPU) (FEG Textiltechnik mbH, Aachen, Germany), respectively. MRI was performed with a pneumoperitoneum at a pressure of 0 and 15 mmHg, which resulted in bulging of the abdomen. The mesh-induced signal voids were semiautomatically segmented and the mesh areas were determined. With the deformations assessed in both mesh types at both pressure conditions, the porosity change of the meshes after 8 weeks of ingrowth was calculated as an indicator of preserved elastic properties. The explanted specimens were examined histologically for the maturity of the scar (collagen I/III ratio). Results In TPU, the in vitro porosity increased constantly, in PVDF, a loss of porosity was observed under mild stresses. In vivo, the mean mesh areas of TPU were 206.8 cm2 (± 5.7 cm2) at 0 mmHg pneumoperitoneum and 274.6 cm2 (± 5.2 cm2) at 15 mmHg; for PVDF the mean areas were 205.5 cm2 (± 8.8 cm2) and 221.5 cm2 (± 11.8 cm2), respectively. The pneumoperitoneum-induced pressure increase resulted in a calculated porosity increase of 8.4% for TPU and of 1.2% for PVDF. The mean collagen I/III ratio was 8.7 (± 0.5) for TPU and 4.7 (± 0.7) for PVDF. Conclusion The elastic properties of TPU mesh implants result in improved tissue integration compared to conventional PVDF meshes, and they adapt more efficiently to the abdominal wall. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 827–833, 2018. Y1 - 2018 U6 - http://dx.doi.org/10.1002/jbm.b.33877 SN - 1552-4981 VL - 106 IS - 2 SP - 827 EP - 833 PB - Wiley CY - New York, NY ER - TY - JOUR A1 - Honarvarfard, Elham A1 - Gamella, Maria A1 - Channaveerappa, Devika A1 - Darie, Costel C. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef A1 - Katz, Evgeny T1 - Electrochemically Stimulated Insulin Release from a Modified Graphene–functionalized Carbon Fiber Electrode JF - Electroanalysis N2 - A graphene-functionalized carbon fiber electrode was modified with adsorbed polyethylenimine to introduce amino functionalities and then with trigonelline and 4-carboxyphenylboronic acid covalently bound to the amino groups. The trigonelline species containing quarterized pyridine groups produced positive charge on the electrode surface regardless of the pH value, while the phenylboronic acid species were neutral below pH 8 and negatively charged above pH 9 (note that their pKa=8.4). The total charge on the monolayer-modified electrode was positive at the neutral pH and negative at pH > 9. Note that 4-carboxyphenylboronic acid was attached to the electrode surface in molar excess to trigonelline, thus allowing the negative charge to dominate on the electrode surface at basic pH. Negatively charged fluorescent dye-labeled insulin (insulin-FITC) was loaded on the modified electrode surface at pH 7.0 due to its electrostatic attraction to the positively charged interface. The local pH in close vicinity to the electrode surface was increased to ca. 9–10 due to consumption of H+ ions upon electrochemical reduction of oxygen proceeding at the potential of −1.0 V (vs. Ag/AgCl) applied on the modified electrode. The process resulted in recharging of the electrode surface to the negative value due to the formation of the negative charge on the phenylboronic acid groups, thus resulting in the electrostatic repulsion of insulin-FITC and stimulating its release from the electrode surface. The insulin release was characterized by fluorescence spectroscopy (using the FITC-labeled insulin), by electrochemical measurements on an iridium oxide, IrOx, electrode and by mass spectrometry. The graphene-functionalized carbon fiber electrode demonstrated significant advantages in the signal-stimulated insulin release comparing with the carbon fiber electrode without the graphene species. Y1 - 2017 U6 - http://dx.doi.org/10.1002/elan.201700095 SN - 1521-4109 VL - 29 IS - 6 SP - 1543 EP - 1553 PB - Wiley-VCH CY - Weinheim ER - TY - CHAP A1 - Abel, Thomas A1 - Bonin, Dominik A1 - Albracht, Kirsten A1 - Zeller, Sebastian A1 - Brüggemann, Gert-Peter A1 - Burkett, Brendan A1 - Strüder, Heiko K. T1 - Kinematic profile of the elite handcyclist T2 - 28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 – 23, 2010 Y1 - 2017 SN - 1999-4168 SP - 140 EP - 141 ER - TY - CHAP A1 - Braunstein, Bjoern A1 - Goldmann, Jan-Peter A1 - Albracht, Kirsten A1 - Sanno, Maximilian A1 - Willwacher, Steffen A1 - Heinrich, Kai A1 - Herrmann, Volker A1 - Brüggemann, Gert-Peter T1 - Joint specific contribution of mechanical power and work during acceleration and top speed in elite sprinters T2 - 31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013 Y1 - 2013 SN - 1999-4168 ER - TY - CHAP A1 - Droszez, Anna A1 - Sanno, Maximilian A1 - Goldmann, Jan-Peter A1 - Albracht, Kirsten A1 - Brüggemann, Gerd-Peter A1 - Braunstein, Bjoern T1 - Differences between take-off behavior during vertical jumps and two artistic elements T2 - 34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016 Y1 - 2016 SN - 1999-4168 SP - 577 EP - 580 ER - TY - CHAP A1 - Goldmann, Jan-Peter A1 - Braunstein, Bjoern A1 - Heinrich, Kai A1 - Sanno, Maximilian A1 - Stäudle, Benjamin A1 - Ritzdorf, Wolfgang A1 - Brüggemann, Gert-Peter A1 - Albracht, Kirsten T1 - Joint work of the take-off leg during elite high jump T2 - Proceedings of the 33th International Conference on Biomechanics in Sports (ISBS) Y1 - 2015 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 - http://dx.doi.org/10.1371/journal.pone.0171562 VL - 12 IS - 2 ER - TY - CHAP A1 - Kolditz, Melanie A1 - Albin, Thivaharan A1 - Fasse, Alessandro A1 - Brüggemann, Gert-Peter A1 - Abel, Dirk A1 - Albracht, Kirsten T1 - Simulative Analysis of Joint Loading During Leg Press Exercise for Control Applications T2 - IFAC-PapersOnLine Y1 - 2015 U6 - http://dx.doi.org/10.1016/j.ifacol.2015.10.179 N1 - IFAC-PapersOnLine 48-20; Conference Paper Archive VL - 48 IS - 20 SP - 435 EP - 440 ER - TY - CHAP A1 - Kolditz, Melanie A1 - Albracht, Kirsten A1 - Fasse, Alessandro A1 - Albin, Thivaharan A1 - Brüggemann, Gert-Peter A1 - Abel, Dirk T1 - Evaluation of an industrial robot as a leg press training device T2 - XV International Symposium on Computer Simulation in Biomechanics July 9th – 11th 2015, Edinburgh, UK Y1 - 2015 SP - 41 EP - 42 ER - TY - THES A1 - Albracht, Kirsten T1 - Influence of mechanical properties of the leg extensor muscletendon units on running economy Y1 - 2010 N1 - Cologne, German Sport Univ., Diss., 2010 PB - Deutsche Sporthochschule Köln CY - Köln ER - TY - JOUR A1 - Hackl, Michael A1 - Wegmann, Kilian A1 - Kahmann, Stephanie Lucina A1 - Heinze, Nicolai A1 - Staat, Manfred A1 - Neiss, Wolfram F. A1 - Scaal, Martin A1 - Müller, Lars P. T1 - Radial shortening osteotomy reduces radiocapitellar contact pressures while preserving valgus stability of the elbow JF - Knee Surgery, Sports Traumatology, Arthroscopy Y1 - 2017 U6 - http://dx.doi.org/10.1007/s00167-017-4468-z SN - 1433-7347 VL - 25 IS - 7 SP - 2280 EP - 2288 PB - Springer CY - Berlin ER - TY - JOUR A1 - Poghossian, Arshak A1 - Werner, Frederik A1 - Buniatyan, V. V. A1 - Wagner, Torsten A1 - Miamoto, K. A1 - Yoshinobu, T. A1 - Schöning, Michael Josef T1 - Towards addressability of light-addressable potentiometric sensors: Shunting effect of non-illuminated region and cross-talk JF - Sensor and Actuators B: Chemical N2 - The LAPS (light-addressable potentiometric sensor) platform is one of the most attractive approaches for chemical and biological sensing with many applications ranging from pH and ion/analyte concentration measurements up to cell metabolism detection and chemical imaging. However, although it is generally accepted that LAPS measurements are spatially resolved, the light-addressability feature of LAPS devices has not been discussed in detail so far. In this work, an extended electrical equivalent-circuit model of the LAPS has been presented, which takes into account possible cross-talk effects due to the capacitive coupling of the non-illuminated region. A shunting effect of the non-illuminated area on the measured photocurrent and addressability of LAPS devices has been studied. It has been shown, that the measured photocurrent will be determined not only by the local interfacial potential in the illuminated region but also by possible interfacial potential changes in the non-illuminated region, yielding cross-talk effects. These findings were supported by the experimental investigations of a penicillin-sensitive multi-spot LAPS and a metal-insulator-semiconductor LAPS as model systems. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.snb.2017.01.047 SN - 0925-4005 IS - 244 SP - 1071 EP - 1079 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jahnke, Siegfried A1 - Roussel, Johanna A1 - Hombach, Thomas A1 - Kochs, Johannes A1 - Fischbach, Andreas A1 - Huber, Gregor A1 - Scharr, Hanno T1 - phenoSeeder - A robot system for automated handling and phenotyping of individual seeds JF - Plant physiology N2 - The enormous diversity of seed traits is an intriguing feature and critical for the overwhelming success of higher plants. In particular, seed mass is generally regarded to be key for seedling development but is mostly approximated by using scanning methods delivering only two-dimensional data, often termed seed size. However, three-dimensional traits, such as the volume or mass of single seeds, are very rarely determined in routine measurements. Here, we introduce a device named phenoSeeder, which enables the handling and phenotyping of individual seeds of very different sizes. The system consists of a pick-and-place robot and a modular setup of sensors that can be versatilely extended. Basic biometric traits detected for individual seeds are two-dimensional data from projections, three-dimensional data from volumetric measures, and mass, from which seed density is also calculated. Each seed is tracked by an identifier and, after phenotyping, can be planted, sorted, or individually stored for further evaluation or processing (e.g. in routine seed-to-plant tracking pipelines). By investigating seeds of Arabidopsis (Arabidopsis thaliana), rapeseed (Brassica napus), and barley (Hordeum vulgare), we observed that, even for apparently round-shaped seeds of rapeseed, correlations between the projected area and the mass of seeds were much weaker than between volume and mass. This indicates that simple projections may not deliver good proxies for seed mass. Although throughput is limited, we expect that automated seed phenotyping on a single-seed basis can contribute valuable information for applications in a wide range of wild or crop species, including seed classification, seed sorting, and assessment of seed quality. Y1 - 2016 U6 - http://dx.doi.org/10.1104/pp.16.01122 SN - 0032-0889 VL - 172 IS - 3 SP - 1358 EP - 1370 PB - Oxford University Press CY - Oxford ER - TY - CHAP A1 - Poghossian, Arshak A1 - Bronder, Thomas A1 - Scheja, S. A1 - Wu, Chunsheng A1 - Metzger-Boddien, C. A1 - Keusgen, M. A1 - Schöning, Michael Josef T1 - Label-free Electrostatic Detection of DNA Amplification by PCR Using Capacitive Field-effect Devices T2 - Procedia Engineering N2 - A capacitive field-effect EIS (electrolyte-insulator-semiconductor) sensor modified with a positively charged weak polyelectrolyte of poly(allylamine hydrochloride) (PAH)/single-stranded probe DNA (ssDNA) bilayer has been used for a label-free electrostatic detection of pathogen-specific DNA amplification via polymerase chain reaction (PCR). The sensor is able to distinguish between positive and negative PCR solutions, to detect the existence of target DNA amplicons in PCR samples and thus, can be used as tool for a quick verification of DNA amplification and the successful PCR process. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.proeng.2016.11.512 SN - 1877-7058 N1 - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary VL - Vol. 168 SP - 514 EP - 517 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Katz, Evgeny A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - Enzyme-based logic gates and circuits - analytical applications and interfacing with electronics JF - Analytical and Bioanalytical Chemistry N2 - The paper is an overview of enzyme-based logic gates and their short circuits, with specific examples of Boolean AND and OR gates, and concatenated logic gates composed of multi-step enzyme-biocatalyzed reactions. Noise formation in the biocatalytic reactions and its decrease by adding a “filter” system, converting convex to sigmoid response function, are discussed. Despite the fact that the enzyme-based logic gates are primarily considered as components of future biomolecular computing systems, their biosensing applications are promising for immediate practical use. Analytical use of the enzyme logic systems in biomedical and forensic applications is discussed and exemplified with the logic analysis of biomarkers of various injuries, e.g., liver injury, and with analysis of biomarkers characteristic of different ethnicity found in blood samples on a crime scene. Interfacing of enzyme logic systems with modified electrodes and semiconductor devices is discussed, giving particular attention to the interfaces functionalized with signal-responsive materials. Future perspectives in the design of the biomolecular logic systems and their applications are discussed in the conclusion. Y1 - 2017 U6 - http://dx.doi.org/10.1007/s00216-016-0079-7 SN - 1618-2650 VL - 409 SP - 81 EP - 94 PB - Springer CY - Berlin ER - TY - CHAP A1 - Bäcker, Matthias A1 - Koch, C. A1 - Geiger, F. A1 - Eber, F. A1 - Gliemann, H. A1 - Poghossian, Arshak A1 - Schöning, Michael Josef T1 - A New Class of Biosensors Based on Tobacco Mosaic Virus and Coat Proteins as Enzyme Nanocarrier T2 - Procedia Engineering Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.proeng.2016.11.228 SN - 1877-7058 N1 - Proceedings of the 30th anniversary Eurosensors Conference – Eurosensors 2016, 4-7. Sepember 2016, Budapest, Hungary VL - Vol. 168 SP - 618 EP - 621 ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy JF - Biological Cybernetics Y1 - 2006 U6 - http://dx.doi.org/10.1007/s00422-006-0070-z SN - 1432-0770 VL - 95 IS - 1 SP - 87 EP - 96 ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Karamanidis, Kiros A1 - Albracht, Kirsten T1 - Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude JF - Journal of Experimental Biology Y1 - 2007 U6 - http://dx.doi.org/10.1242/jeb.003814 SN - 0022-0949 VL - 210 IS - 15 SP - 2743 EP - 2753 ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, A. A1 - Baltzopoulos, V. T1 - Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo JF - Journal of Biomechanics Y1 - 2008 U6 - http://dx.doi.org/10.1016/j.jbiomech.2008.04.020 SN - 0021-9290 VL - 41 SP - 2211 EP - 2218 ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Karamanidis, Kiros A1 - Mademli, Lida A1 - Albracht, Kirsten T1 - Plasticity of the human tendon to short and long-term mechanical loading JF - Exercise and Sport Sciences Reviews Y1 - 2009 U6 - http://dx.doi.org/10.1097/JES.0b013e31819c2e1d SN - 1538-3008 VL - 37 IS - 2 SP - 66 EP - 72 ER - TY - JOUR A1 - Aggeloussis, Nickos A1 - Giannakou, Erasmia A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Reproducibility of fascicle length and pennation angle of gastrocnemius medialis in human gait in vivo JF - Gait and Posture N2 - The purpose of the current study was to examine the reproducibility of fascicle length and pennation angle of gastrocnemius medialis while human walking. To the best of our knowledge, this is the first study of the reproducibility of fascicle length and pennation angle of gastrocnemius medialis in vivo during human gait. Twelve males performed 10 gait trials on a treadmill, in 2 separate days. B-mode ultrasonography, with the ultrasound probe firmly adjusted in the transverse and frontal planes using a special cast, was used to measure the fascicle length and the pennation angle of the gastrocnemius medialis (GM). A Vicon 624 system with three cameras operating at 120 Hz was also used to record the ankle and knee joint angles. The results showed that measurements of fascicle length and pennation angle showed high reproducibility during the gait cycle, both within the same day and between different days. Moreover, the root mean square differences between the repeated waveforms of both variables were very small, compared with their ranges (fascicle length: RMS = ∼3 mm, range: 38–63 mm; pennation angle: RMS = ∼1.5°, range: 22–32°). However, their reproducibility was lower compared to the joint angles. It was found that representative data have to be derived by a wide number of gait trials (fascicle length ∼six trials, pennation angle more than 10 trials), to assure the reliability of the fascicle length and pennation angle in human gait. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.gaitpost.2009.08.249 SN - 0966-6362 VL - 31 IS - 1 SP - 73 EP - 77 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Peper, Andreas A1 - Bierbaum, Stefanie A1 - Albracht, Kirsten T1 - Plasticity of human Achilles tendon mechanical and morphological properties in response to cyclic strain JF - Journal of Biomechanics N2 - The purpose of the current study in combination with our previous published data (Arampatzis et al., 2007) was to examine the effects of a controlled modulation of strain magnitude and strain frequency applied to the Achilles tendon on the plasticity of tendon mechanical and morphological properties. Eleven male adults (23.9±2.2 yr) participated in the study. The participants exercised one leg at low magnitude tendon strain (2.97±0.47%), and the other leg at high tendon strain magnitude (4.72±1.08%) of similar frequency (0.5 Hz, 1 s loading, 1 s relaxation) and exercise volume (integral of the plantar flexion moment over time) for 14 weeks, 4 days per week, 5 sets per session. The exercise volume was similar to the intervention of our earlier study (0.17 Hz frequency; 3 s loading, 3 s relaxation) allowing a direct comparison of the results. Before and after the intervention ankle joint moment has been measured by a dynamometer, tendon–aponeurosis elongation by ultrasound and cross-sectional area of the Achilles tendon by magnet resonance images (MRI). We found a decrease in strain at a given tendon force, an increase in tendon–aponeurosis stiffness and tendon elastic modulus of the Achilles tendon only in the leg exercised at high strain magnitude. The cross-sectional area (CSA) of the Achilles tendon did not show any statistically significant (P>0.05) differences to the pre-exercise values in both legs. The results indicate a superior improvement in tendon properties (stiffness, elastic modulus and CSA) at the low frequency (0.17 Hz) compared to the high strain frequency (0.5 Hz) protocol. These findings provide evidence that the strain magnitude applied to the Achilles tendon should exceed the value, which occurs during habitual activities to trigger adaptational effects and that higher tendon strain duration per contraction leads to superior tendon adaptational responses. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.jbiomech.2010.08.014 SN - 0021-9290 VL - 43 IS - 16 SP - 3073 EP - 3079 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Karamanidis, Kiros A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Catala, Maria Moreno A1 - Goldmann, Jan-Peter A1 - Brüggemann, Gert-Peter T1 - Lower leg musculoskeletal geometry and sprint performance JF - Gait and Posture N2 - The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components. Y1 - 2011 U6 - http://dx.doi.org/10.1016/j.gaitpost.2011.03.009 SN - 0966-6362 VL - 34 IS - 1 SP - 138 EP - 141 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Exercise-induced changes in triceps surae tendon stiffness and muscle strength affect running economy in humans JF - European Journal of Applied Physiology Y1 - 2013 U6 - http://dx.doi.org/10.1007/s00421-012-2585-4 SN - 1439-6327 VL - 113 IS - 6 SP - 1605 EP - 1615 PB - Springer CY - Berlin ER - TY - JOUR A1 - Seynnes, O. R. A1 - Bojsen-Moller, J. A1 - Albracht, Kirsten A1 - Arndt, A. A1 - Cronin, N. J. A1 - Finni, T. A1 - Magnusson, S. P. T1 - Ultrasound-based testing of tendon mechanical properties: a critical evaluation JF - Journal of Applied Physiology Y1 - 2015 U6 - http://dx.doi.org/10.1152/japplphysiol.00849.2014 SN - 8750-7587 VL - 118 IS - 2 SP - 133 EP - 141 ER - TY - JOUR A1 - Belavy, Daniel L. A1 - Albracht, Kirsten A1 - Bruggemann, Gert-Peter A1 - Vergroesen, Pieter-Paul A. A1 - Dieen, Jaap H. van T1 - Can exercise positively influence the intervertebral disc? JF - Sports Medicine N2 - To better understand what kinds of sports and exercise could be beneficial for the intervertebral disc (IVD), we performed a review to synthesise the literature on IVD adaptation with loading and exercise. The state of the literature did not permit a systematic review; therefore, we performed a narrative review. The majority of the available data come from cell or whole-disc loading models and animal exercise models. However, some studies have examined the impact of specific sports on IVD degeneration in humans and acute exercise on disc size. Based on the data available in the literature, loading types that are likely beneficial to the IVD are dynamic, axial, at slow to moderate movement speeds, and of a magnitude experienced in walking and jogging. Static loading, torsional loading, flexion with compression, rapid loading, high-impact loading and explosive tasks are likely detrimental for the IVD. Reduced physical activity and disuse appear to be detrimental for the IVD. We also consider the impact of genetics and the likelihood of a ‘critical period’ for the effect of exercise in IVD development. The current review summarises the literature to increase awareness amongst exercise, rehabilitation and ergonomic professionals regarding IVD health and provides recommendations on future directions in research. KW - Intradiscal Pressure KW - Annulus Fibrosus KW - Disc Degeneration KW - Nucleus Pulposus KW - Intervertebral Disc Y1 - 2016 U6 - http://dx.doi.org/10.1007/s40279-015-0444-2 SN - 1179-2035 VL - 46 IS - 4 SP - 473 EP - 485 PB - Springer CY - Berlin ER - TY - JOUR A1 - Kolditz, Melanie A1 - Albin, Thivaharan A1 - Abel, Dirk A1 - Fasse, Alessandro A1 - Brüggemann, Gert-Peter A1 - Albracht, Kirsten T1 - Evaluation of foot position and orientation as manipulated variables to control external knee adduction moments in leg extension training JF - Computer methods and programs in biomedicine N2 - Background and Objective Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed. Methods Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position. Results Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector. Conclusions The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training. KW - External knee adduction moments KW - Manipulated variables KW - Inverse dynamic problem KW - Inverse kinematic problem KW - Musculoskeletal model Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.cmpb.2016.09.005 SN - 0169-2607 N1 - Part of special issue: "SI: Personalised Models and System Identification" VL - 171 SP - 81 EP - 86 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - Tap chi Khoa hoc & ung dung - Dai hoc Ton Duc Thang Y1 - 2012 N1 - = Journal of Applied Sciences - Ton Duc Thang University VL - 19 SP - 45 EP - 47 ER - TY - JOUR A1 - Levers, A. A1 - Staat, Manfred A1 - Laack, Walter van T1 - Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis JF - Orthopedic Practice Y1 - 2016 VL - 47 IS - 11 SP - 521 EP - 528 ER - TY - CHAP A1 - Tran, Ngoc Trinh A1 - Tran, Thanh Ngoc A1 - Matthies, Hermann G. A1 - Stavroulakis, Georgios Eleftherios A1 - Staat, Manfred T1 - FEM Shakedown of uncertain structures by chance constrained programming T2 - PAMM Proceedings in Applied Mathematics and Mechanics Y1 - 2016 U6 - http://dx.doi.org/10.1002/pamm.201610346 SN - 1617-7061 N1 - Special Issue: Joint 87th Annual Meeting of the International Association of Applied Mathematics and Mechanics (GAMM) and Deutsche Mathematiker-Vereinigung VL - 16 IS - 1 SP - 715 EP - 716 ER - TY - CHAP A1 - Bhattarai, Aroj A1 - Frotscher, Ralf A1 - Staat, Manfred ED - Natal Jorge, Renato T1 - Significance of fibre geometry on passive-active response of pelvic muscles to evaluate pelvic dysfunction T2 - BioMedWomen: Proceedings of the international conference on clinical and bioengineering for women's health Y1 - 2016 SN - 978-1-138-02910-1 SP - 185 EP - 188 PB - CRC Press CY - Boca Raton ER - TY - JOUR A1 - Hackl, M. A1 - Andermahr, J. A1 - Staat, Manfred A1 - Bremer, I. A1 - Borggrefe, J. A1 - Prescher, A. A1 - Müller, L. P. A1 - Wegmann, K. T1 - Suture button reconstruction of the central band of the interosseous membrane in Essex-Lopresti lesions: a comparative biomechanical investigation JF - The Journal of Hand Surgery (European Volume) Y1 - 2017 U6 - http://dx.doi.org/10.1177/1753193416665943 SN - 2043-6289 (Online) SN - 1753-1934 (Print) VL - 42 IS - 4 SP - 370 EP - 376 PB - Sage CY - London ER - TY - JOUR A1 - Albanna, W. A1 - Conzen, C. A1 - Weiss, M. A1 - Clusmann, H. A1 - Fuest, M. A1 - Mueller, M. A1 - Brockmann, M.A. A1 - Vilser, W. A1 - Schmidt-Trucksäss, A. A1 - Hoellig, A. A1 - Seiz, M. A1 - Thomé, C. A1 - Kotliar, Konstantin A1 - Schubert, G.A. T1 - Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study JF - PLoS ONE N2 - Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2–14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort. Y1 - 2016 U6 - http://dx.doi.org/10.1371/journal.pone.0158781 SN - 1932-6203 VL - 11 IS - 7 PB - PLOS CY - San Francisco ER - TY - JOUR A1 - Bäcker, Matthias A1 - Koch, Claudia A1 - Eiben, Sabine A1 - Geiger, Fania A1 - Eber, Fabian A1 - Gliemann, Hartmut A1 - Poghossian, Arshak A1 - Wege, Christina A1 - Schöning, Michael Josef T1 - Tobacco mosaic virus as enzyme nanocarrier for electrochemical biosensors JF - Sensors and Actuators B: Chemical N2 - The conjunction of (bio-)chemical recognition elements with nanoscale biological building blocks such as virus particles is considered as a very promising strategy for the creation of biohybrids opening novel opportunities for label-free biosensing. This work presents a new approach for the development of biosensors using tobacco mosaic virus (TMV) nanotubes or coat proteins (CPs) as enzyme nanocarriers. Sensor chips combining an array of Pt electrodes loaded with glucose oxidase (GOD)-modified TMV nanotubes or CP aggregates were used for amperometric detection of glucose as a model system for the first time. The presence of TMV nanotubes or CPs on the sensor surface allows binding of a high amount of precisely positioned enzymes without substantial loss of their activity, and may also ensure accessibility of their active centers for analyte molecules. Specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CPs was achieved via bioaffinity binding. These layouts were tested in parallel with glucose sensors with adsorptively immobilized [SA]-GOD, as well as [SA]-GOD crosslinked with glutardialdehyde, and came out to exhibit superior sensor performance. The achieved results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for future applications in biosensorics and biochips. Y1 - 2017 U6 - http://dx.doi.org/10.1016/j.snb.2016.07.096 SN - 0925-4005 VL - 238 SP - 716 EP - 722 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Tran, Ngoc Trinh A1 - Tran, Thanh Ngoc A1 - Matthies, H. G. A1 - Stavroulakis, G. E. A1 - Staat, Manfred ED - Papadrakakis, M. T1 - Shakedown analysis of plate bending analysis under stochastic uncertainty by chance constrained programming T2 - ECCOMAS Congress 2016, VII European Congress on Computational Methods in Applied Sciences and Engineering. Crete Island, Greece, 5–10 June 2016 Y1 - 2016 ER - TY - JOUR A1 - Molinnus, Denise A1 - Sorich, Maren A1 - Bartz, Alexander A1 - Siegert, Petra A1 - Willenberg, Holger S. A1 - Lisdat, Fred A1 - Poghossian, Arshak A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Towards an adrenaline biosensor based on substrate recycling amplification in combination with an enzyme logic gate JF - Sensors and Actuators B: Chemical N2 - An amperometric biosensor using a substrate recycling principle was realized for the detection of low adrenaline concentrations (1 nM) by measurements in phosphate buffer and Ringer’s solution at pH 6.5 and pH 7.4, respectively. In proof-of-concept experiments, a Boolean logic-gate principle has been applied to develop a digital adrenaline biosensor based on an enzyme AND logic gate. The obtained results demonstrate that the developed digital biosensor is capable for a rapid qualitative determination of the presence/absence of adrenaline in a YES/NO statement. Such digital biosensor could be used in clinical diagnostics for the control of a correct insertion of a catheter in the adrenal veins during adrenal venous-sampling procedure. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.snb.2016.06.064 SN - 0925-4005 VL - 237 SP - 190 EP - 195 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Knobe, M. A1 - Giesen, M. A1 - Plate, S. A1 - Gradl-Dietsch, G. A1 - Buecking, B. A1 - Eschbach, D. A1 - Laack, Walter van A1 - Pape, H.-C. T1 - The Aachen mobility and balance index to measure physiological falls risk: a comparison with the Tinetti POMA scale JF - European Journal Of Trauma And Emergency Surgery N2 - Purpose The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale. Methods For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland–Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated. Results The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = −0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points). Conclusion The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status. KW - Tinetti test KW - Mobility KW - Mobility tests KW - Ground-level falls KW - Elderly KW - Fall prevention KW - Co-managed care KW - Balance Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00068-016-0693-2 SN - 1863-9941 VL - 42 IS - 5 SP - 537 EP - 545 PB - Springer CY - Berlin ER - TY - JOUR A1 - Doll, Theodor A1 - Wagner, Torsten A1 - Wagner, Patrick A1 - Schöning, Michael Josef T1 - Engineering of functional interfaces / Theodor Doll ; Torsten Wagner ; Patrick Wagner ; Michael J. Schöning (eds.) JF - Physica status solidi (a) Y1 - 2016 U6 - http://dx.doi.org/10.1002/pssa.201670641 SN - 1862-6319 VL - 213 IS - 6 SP - 1393 EP - 1394 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Wagner, Torsten A1 - Vornholt, Wolfgang A1 - Werner, Frederik A1 - Yoshinobu, Tatsuo A1 - Miyamoto, Ko-Ichiro A1 - Keusgen, Michael A1 - Schöning, Michael Josef T1 - Light-addressable potentiometric sensor (LAPS) combined with magnetic beads for pharmaceutical screening JF - Physics in medicine N2 - The light-addressable potentiometric sensor (LAPS) has the unique feature to address different regions of a sensor surface without the need of complex structures. Measurements at different locations on the sensor surface can be performed in a common analyte solution, which distinctly simplifies the fluidic set-up. However, the measurement in a single analyte chamber prevents the application of different drugs or different concentrations of a drug to each measurement spot at the same time as in the case of multi-reservoir-based set-ups. In this work, the authors designed a LAPS-based set-up for cell culture screening that utilises magnetic beads loaded with the endotoxin (lipopolysaccharides, LPS), to generate a spatially distributed gradient of analyte concentration. Different external magnetic fields can be adjusted to move the magnetic beads loaded with a specific drug within the measurement cell. By recording the metabolic activities of a cell layer cultured on top of the LAPS surface, this work shows the possibility to apply different concentrations of a sample along the LAPS measurement spots within a common analyte solution. Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.phmed.2016.03.001 SN - 2352-4510 VL - 2016 IS - 1 SP - 2 EP - 7 ER - TY - JOUR A1 - Miyamoto, Ko-Ichiro A1 - Sato, Takuya A1 - Abe, Minami A1 - Wagner, Torsten A1 - Schöning, Michael Josef A1 - Yoshinobu, Tatsuo T1 - Light-addressable potentiometric sensor as a sensing element in plug-based microfluidic devices JF - Micromachines N2 - A plug-based microfluidic system based on the principle of the light-addressable potentiometric sensor (LAPS) is proposed. The LAPS is a semiconductor-based chemical sensor, which has a free addressability of the measurement point on the sensing surface. By combining a microfluidic device and LAPS, ion sensing can be performed anywhere inside the microfluidic channel. In this study, the sample solution to be measured was introduced into the channel in a form of a plug with a volume in the range of microliters. Taking advantage of the light-addressability, the position of the plug could be monitored and pneumatically controlled. With the developed system, the pH value of a plug with a volume down to 400 nL could be measured. As an example of plug-based operation, two plugs were merged in the channel, and the pH change was detected by differential measurement. KW - light-addressable potentiometric sensor KW - plug-based microfluidic device KW - chemical sensor Y1 - 2016 U6 - http://dx.doi.org/10.3390/mi7070111 SN - 2072-666X N1 - This article belongs to the Special Issue "Micro/Nano Devices for Chemical Analysis" VL - 7 IS - 7 SP - 111 PB - MDPI CY - Basel ER - TY - CHAP A1 - Schreiber, Marc A1 - Kraft, Bodo A1 - Zündorf, Albert T1 - Cost-efficient quality assurance of natural language processing tools through continuous monitoring with continuous integration T2 - 3rd International Workshop on Software Engineering Research and Industrial Practice Y1 - 2016 U6 - http://dx.doi.org/10.1145/2897022.2897029 N1 - SER&IP’16, May 17 2016, Austin, TX, USA SP - 46 EP - 52 ER - TY - JOUR A1 - Wegmann, Kilian A1 - Hackl, Michael A1 - Staat, Manfred A1 - Mayer, Katharina A1 - Müller, Lars-Peter T1 - Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results JF - Knee surgery, sports traumatology, arthroscopy N2 - While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4079-0 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 58 EP - 59 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hackl, Michael A1 - Leschinger, T. A1 - Staat, Manfred A1 - Müller, Lars-Peter A1 - Wegmann, Kilian T1 - Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation JF - Knee surgery, sports traumatology, arthroscopy N2 - Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 130 EP - 131 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hackl, Michael A1 - Kahmann, Stephanie Lucina A1 - Wegmann, Kilian A1 - Ries, Christian A1 - Staat, Manfred A1 - Müller, Lars-Peter T1 - Shortening osteotomy of the proximal radius — a treatment option for isolated osteoarthritis of the lateral column of the elbow joint? JF - Knee surgery, sports traumatology, arthroscopy N2 - Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue. While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 128 EP - 129 PB - Springer CY - Berlin ER - TY - JOUR A1 - Hackl, Michael A1 - Müller, Lars-Peter A1 - Staat, Manfred A1 - Kahmann, Stephanie Lucina A1 - Wegmann, Kilian T1 - Proximal phalangeal neck fractures of the hand — a biomechanical comparison of three fixation techniques JF - Knee surgery, sports traumatology, arthroscopy N2 - Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis. Y1 - 2016 U6 - http://dx.doi.org/10.1007/s00167-016-4080-7 SN - 0942-2056 VL - Volume 24 IS - Supplement 1 SP - 148 EP - 149 PB - Springer CY - Berlin ER - TY - CHAP A1 - Kahmann, Stephanie A1 - Hackl, Michael A1 - Wegmann, Kilian A1 - Müller, Lars-Peter A1 - Staat, Manfred ED - Erni, Daniel T1 - Impact of a proximal radial shortening osteotomy on the distribution of forces and the stability of the elbow T2 - 1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen N2 - The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient’s quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student ́s t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly. Y1 - 2016 U6 - http://dx.doi.org/10.17185/duepublico/40821 SP - 7 EP - 8 PB - Universität Duisburg-Essen CY - Duisburg ER -