@article{AlbrachtArampatzis2006,
  author    = {Albracht, Kirsten and Arampatzis, Adamantios},
  title     = {Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy},
  series = {Biological Cybernetics},
  volume    = {95},
  journal   = {Biological Cybernetics},
  number    = {1},
  issn      = {1432-0770},
  doi       = {10.1007/s00422-006-0070-z},
  pages     = {87 -- 96},
  year      = {2006},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2018,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Evaluation of passively induced shoulder stretch reflex using an isokinetic dynamometer in male overhead athletes},
  series = {Isokinetics and Exercise Science},
  volume    = {26},
  journal   = {Isokinetics and Exercise Science},
  number    = {4},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1878-5913},
  doi       = {10.3233/IES-184111},
  pages     = {265 -- 274},
  year      = {2018},
  abstract  = {BACKGROUND: Muscle stretch reflexes are widely considered to beneficially influence joint stability and power generation in the lower limbs. While in the upper limbs and especially in the muscles surrounding the shoulder joint such evidence is lacking. OBJECTIVE: To quantify the electromyographical response in the muscles crossing the shoulder of specifically trained overhead athletes to an anterior perturbation force. METHODS: Twenty healthy male participants performed six sets of different external shoulder rotation stretches on an isokinetic dynamometer over a range of amplitudes and muscle pre-activation moment levels. All stretches were applied with a dynamometer acceleration of 10,000∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexes were not observed in all experimental conditions. The reflex latencies revealed a significant muscle main effect (F (2,228) = 99.31, p< 0.001; η2= 0.466; f= 0.934) and a pre-activation main effect (F (1,228) = 142.21, p< 0.001; η2= 0.384; f= 1.418). The stretch reflex amplitude yielded a significant pre-activation main effect (F (1,222) = 470.373, p< 0.001; η2= 0.679; f= 1.454). CONCLUSION: Short latency muscle reflexes showed a tendency to an anterior to posterior muscle recruitment whereby the main internal rotator muscles of the shoulder revealed the most consistent results.},
  language  = {en}
}
@article{QuittmannAbelAlbrachtetal.2020,
  author    = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Meskemper, Joshua and Foitschik, Tina and Str{\"u}der, Heiko K.},
  title     = {Biomechanics of handcycling propulsion in a 30-min continuous load test at lactate threshold: Kinetics, kinematics, and muscular activity in able-bodied participants},
  series = {European Journal of Applied Physiology},
  journal   = {European Journal of Applied Physiology},
  number    = {120},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1439-6327},
  doi       = {10.1007/s00421-020-04373-x},
  pages     = {1403 -- 1415},
  year      = {2020},
  abstract  = {Purpose This study aims to investigate the biomechanics of handcycling during a continuous load trial (CLT) to assess the mechanisms underlying fatigue in upper body exercise. Methods Twelve able-bodied triathletes performed a 30-min CLT at a power output corresponding to lactate threshold in a racing recumbent handcycle mounted on a stationary ergometer. During the CLT, ratings of perceived exertion (RPE), tangential crank kinetics, 3D joint kinematics, and muscular activity of ten muscles of the upper extremity and trunk were examined using motion capturing and surface electromyography. Results During the CLT, spontaneously chosen cadence and RPE increased, whereas crank torque decreased. Rotational work was higher during the pull phase. Peripheral RPE was higher compared to central RPE. Joint range of motion decreased for elbow-flexion and radial-duction. Integrated EMG (iEMG) increased in the forearm flexors, forearm extensors, and M. deltoideus (Pars spinalis). An earlier onset of activation was found for M. deltoideus (Pars clavicularis), M. pectoralis major, M. rectus abdominis, M. biceps brachii, and the forearm flexors. Conclusion Fatigue-related alterations seem to apply analogously in handcycling and cycling. The most distal muscles are responsible for force transmission on the cranks and might thus suffer most from neuromuscular fatigue. The findings indicate that peripheral fatigue (at similar lactate values) is higher in handcycling compared to leg cycling, at least for inexperienced participants. An increase in cadence might delay peripheral fatigue by a reduced vascular occlusion. We assume that the gap between peripheral and central fatigue can be reduced by sport-specific endurance training.},
  language  = {en}
}
@inproceedings{PohleFroehlichDalitzRichteretal.2020,
  author    = {Pohle-Fr{\"o}hlich, Regina and Dalitz, Christoph and Richter, Charlotte and Hahnen, Tobias and St{\"a}udle, Benjamin and Albracht, Kirsten},
  title     = {Estimation of muscle fascicle orientation in ultrasonic images},
  series = {Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 5},
  booktitle = {Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications - Volume 5},
  publisher = {SciTePress},
  address   = {Set{\´u}bal, Portugal},
  isbn      = {978-989-758-402-2},
  doi       = {10.5220/0008933900790086},
  pages     = {79 -- 86},
  year      = {2020},
  abstract  = {We compare four different algorithms for automatically estimating the muscle fascicle angle from ultrasonic images: the vesselness filter, the Radon transform, the projection profile method and the gray level cooccurence matrix (GLCM). The algorithm results are compared to ground truth data generated by three different experts on 425 image frames from two videos recorded during different types of motion. The best agreement with the ground truth data was achieved by a combination of pre-processing with a vesselness filter and measuring the angle with the projection profile method. The robustness of the estimation is increased by applying the algorithms to subregions with high gradients and performing a LOESS fit through these estimates.},
  language  = {en}
}
@article{WerkhausenAlbrachtCroninetal.2017,
  author    = {Werkhausen, Amelie and Albracht, Kirsten and Cronin, Neil J. and Meier, Rahel and Mojsen-Moeller, Jens and Seynnes, Olivier R.},
  title     = {Modulation of muscle-tendon interaction in the human triceps surae during an energy dissipation task},
  series = {Journal of Experimental Biology},
  volume    = {220},
  journal   = {Journal of Experimental Biology},
  number    = {22},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.164111},
  pages     = {4141 -- 4149},
  year      = {2017},
  language  = {en}
}
@article{RittwegerAlbrachtFluecketal.2018,
  author    = {Rittweger, J{\"o}rn and Albracht, Kirsten and Fl{\"u}ck, Martin and Ruoss, Severin and Brocca, Lorenza and Longa, Emanuela and Moriggi, Manuela and Seynnes, Olivier and Di Giulio, Irene and Tenori, Leonardo and Vignoli, Alessia and Capri, Miriam and Gelfi, Cecilia and Luchinat, Claudio and Franceschi, Claudio and Bottinelli, Roberto and Cerretelli, Paolo and Narici, Marco},
  title     = {Sarcolab pilot study into skeletal muscle's adaptation to longterm spaceflight},
  series = {npj Microgravity},
  volume    = {4},
  journal   = {npj Microgravity},
  number    = {1},
  publisher = {Nature Portfolio},
  issn      = {2373-8065},
  doi       = {10.1038/s41526-018-0052-1},
  pages     = {1 -- 9},
  year      = {2018},
  language  = {en}
}
@article{WerkhausenCroninAlbrachtetal.2019,
  author    = {Werkhausen, Amelie and Cronin, Neil J. and Albracht, Kirsten and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R.},
  title     = {Distinct muscle-tendon interaction during running at different speeds and in different loading conditions},
  series = {Journal of Applied Physiology},
  volume    = {127},
  journal   = {Journal of Applied Physiology},
  number    = {1},
  issn      = {1522-1601},
  doi       = {10.1152/japplphysiol.00710.2018},
  pages     = {246 -- 253},
  year      = {2019},
  language  = {en}
}
@article{CapriMorsianiSantoroetal.2019,
  author    = {Capri, Miriam and Morsiani, Cristina and Santoro, Aurelia and Moriggi, Manuela and Conte, Maria and Martucci, Morena and Bellavista, Elena and Fabbri, Cristina and Giampieri, Enrico and Albracht, Kirsten and Fl{\"u}ck, Martin and Ruoss, Severin and Brocca, Lorenza and Canepari, Monica and Longa, Emanuela and Giulio, Irene Di and Bottinelli, Roberto and Cerretelli, Paolo and Salvioli, Stefano and Gelfi, Cecilia and Franceschi, Claudio and Narici, Marco and Rittweger, J{\"o}rn},
  title     = {Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting},
  series = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology},
  volume    = {33},
  journal   = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology},
  number    = {4},
  doi       = {10.1096/fj.201801625R},
  pages     = {5168 -- 5180},
  year      = {2019},
  language  = {en}
}
@article{QuittmannAbelAlbrachtetal.2019,
  author    = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Str{\"u}der, Heiko K.},
  title     = {Reliability of muscular activation patterns and their alterations during incremental handcycling in able-bodied participants},
  series = {Sports Biomechanics},
  journal   = {Sports Biomechanics},
  number    = {Article in press},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1752-6116},
  doi       = {10.1080/14763141.2019.1593496},
  year      = {2019},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2020,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Increased shoulder muscle stretch reflex elicitability in supine subject posture},
  series = {Isokinetics and Exercise Science},
  volume    = {28},
  journal   = {Isokinetics and Exercise Science},
  number    = {2},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1878-5913},
  doi       = {10.3233/IES-192219},
  pages     = {139 -- 146},
  year      = {2020},
  abstract  = {BACKGROUND: Muscle stretch reflexes are widely used to examine neural muscle function. The knowledge of reflex response in muscles crossing the shoulder is limited. OBJECTIVE: To quantify reflex modulation according to various subject postures and different procedures of muscle pre-activation steering. METHODS: Thirteen healthy male participants performed two sets of external shoulder rotation stretches in various positions and with different procedures of muscle pre-activation steering on an isokinetic dynamometer over a range of two different pre-activation levels. All stretches were applied with a dynamometer acceleration of 104∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexive response was observed in all tested muscles in all experimental conditions. The reflex elicitation rate revealed a significant muscle main effect (F (5,288) = 2.358, ρ= 0.040; η2= 0.039; f= 0.637) and a significant test condition main effect (F (1,288) = 5.884, ρ= 0.016; η2= 0.020; f= 0.143). Reflex latency revealed a significant muscle pre-activation level main effect (F (1,274) = 5.008, ρ= 0.026; η2= 0.018; f= 0.469). CONCLUSION: Muscular reflexive response was more consistent in the primary internal rotators of the shoulder. Supine posture in combination with visual feedback of muscle pre-activation level enhanced the reflex elicitation rate.},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2021,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men},
  series = {Journal of Electromyography and Kinesiology},
  volume    = {62},
  journal   = {Journal of Electromyography and Kinesiology},
  number    = {Article 102611},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1050-6411},
  doi       = {10.1016/j.jelekin.2021.102611},
  year      = {2021},
  abstract  = {Until now the reproducibility of the short latency stretch reflex of the internal rotator muscles of the glenohumeral joint has not been identified. Twenty-three healthy male participants performed three sets of external shoulder rotation stretches with various pre-activation levels on two different dates of measurement to assess test-retest reliability. All stretches were applied with a dynamometer acceleration of 104°/s2 and a velocity of 150°/s. Electromyographical response was measured via surface EMG. Reflex latencies showed a pre-activation effect (ƞ2 = 0,355). ICC ranged from 0,735 to 0,909 indicating an overall "good" relative reliability. SRD 95\% lay between ±7,0 to ±12,3 ms.. The reflex gain showed overall poor test-retest reproducibility. The chosen methodological approach presented a suitable test protocol for shoulder muscles stretch reflex latency evaluation. A proof-of-concept study to validate the presented methodical approach in shoulder involvement including subjects with clinically relevant conditions is recommended.},
  language  = {en}
}
@article{ZangeSchopenAlbrachtetal.2017,
  author    = {Zange, Jochen and Schopen, Kathrin and Albracht, Kirsten and Gerlach, Darius A. and Frings-Meuthen, Petra and Maffiuletti, Nicola A. and Bloch, Wilhelm and Rittweger, J{\"o}rn},
  title     = {Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial},
  series = {Plos one},
  volume    = {12},
  journal   = {Plos one},
  number    = {2},
  doi       = {10.1371/journal.pone.0171562},
  year      = {2017},
  language  = {en}
}
@inproceedings{GoldmannBraunsteinHeinrichetal.2015,
  author    = {Goldmann, Jan-Peter and Braunstein, Bjoern and Heinrich, Kai and Sanno, Maximilian and St{\"a}udle, Benjamin and Ritzdorf, Wolfgang and Br{\"u}ggemann, Gert-Peter and Albracht, Kirsten},
  title     = {Joint work of the take-off leg during elite high jump},
  series = {Proceedings of the 33th International Conference on Biomechanics in Sports (ISBS)},
  booktitle = {Proceedings of the 33th International Conference on Biomechanics in Sports (ISBS)},
  pages     = {3 S.},
  year      = {2015},
  language  = {en}
}
@inproceedings{DroszezSannoGoldmannetal.2016,
  author    = {Droszez, Anna and Sanno, Maximilian and Goldmann, Jan-Peter and Albracht, Kirsten and Br{\"u}ggemann, Gerd-Peter and Braunstein, Bjoern},
  title     = {Differences between take-off behavior during vertical jumps and two artistic elements},
  series = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016},
  booktitle = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016},
  issn      = {1999-4168},
  pages     = {577 -- 580},
  year      = {2016},
  language  = {en}
}
@inproceedings{AbelBoninAlbrachtetal.2010,
  author    = {Abel, Thomas and Bonin, Dominik and Albracht, Kirsten and Zeller, Sebastian and Br{\"u}ggemann, Gert-Peter and Burkett, Brendan and Str{\"u}der, Heiko K.},
  title     = {Kinematic profile of the elite handcyclist},
  series = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010},
  booktitle = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010},
  issn      = {1999-4168},
  pages     = {140 -- 141},
  year      = {2010},
  language  = {en}
}
@inproceedings{BraunsteinGoldmannAlbrachtetal.2013,
  author    = {Braunstein, Bjoern and Goldmann, Jan-Peter and Albracht, Kirsten and Sanno, Maximilian and Willwacher, Steffen and Heinrich, Kai and Herrmann, Volker and Br{\"u}ggemann, Gert-Peter},
  title     = {Joint specific contribution of mechanical power and work during acceleration and top speed in elite sprinters},
  series = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013},
  booktitle = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013},
  issn      = {1999-4168},
  year      = {2013},
  language  = {en}
}
@phdthesis{Albracht2010,
  author    = {Albracht, Kirsten},
  title     = {Influence of mechanical properties of the leg extensor muscletendon units on running economy},
  publisher = {Deutsche Sporthochschule K{\"o}ln},
  address   = {K{\"o}ln},
  pages     = {X, 1221 Bl. : graph. Darst.},
  year      = {2010},
  language  = {en}
}
@inproceedings{KolditzAlbrachtFasseetal.2015,
  author    = {Kolditz, Melanie and Albracht, Kirsten and Fasse, Alessandro and Albin, Thivaharan and Br{\"u}ggemann, Gert-Peter and Abel, Dirk},
  title     = {Evaluation of an industrial robot as a leg press training device},
  series = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK},
  booktitle = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK},
  pages     = {41 -- 42},
  year      = {2015},
  language  = {en}
}
@inproceedings{KolditzAlbinFasseetal.2015,
  author    = {Kolditz, Melanie and Albin, Thivaharan and Fasse, Alessandro and Br{\"u}ggemann, Gert-Peter and Abel, Dirk and Albracht, Kirsten},
  title     = {Simulative Analysis of Joint Loading During Leg Press Exercise for Control Applications},
  series = {IFAC-PapersOnLine},
  volume    = {48},
  booktitle = {IFAC-PapersOnLine},
  number    = {20},
  doi       = {10.1016/j.ifacol.2015.10.179},
  pages     = {435 -- 440},
  year      = {2015},
  language  = {en}
}
@article{WaldvogelRitzmannFreyleretal.2021,
  author    = {Waldvogel, Janice and Ritzmann, Ramona and Freyler, Kathrin and Helm, Michael and Monti, Elena and Albracht, Kirsten and St{\"a}udle, Benjamin and Gollhofer, Albert and Narici, Marco},
  title     = {The Anticipation of Gravity in Human Ballistic Movement},
  series = {Frontiers in Physiology},
  journal   = {Frontiers in Physiology},
  publisher = {Frontiers},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2021.614060},
  year      = {2021},
  abstract  = {Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.},
  language  = {en}
}