TY - JOUR A1 - Heieis, Jule A1 - Böcker, Jonas A1 - D'Angelo, Olfa A1 - Mittag, Uwe A1 - Albracht, Kirsten A1 - Schönau, Eckhard A1 - Meyer, Andreas A1 - Voigtmann, Thomas A1 - Rittweger, Jörn T1 - Curvature of gastrocnemius muscle fascicles as function of muscle–tendon complex length and contraction in humans JF - Physiological Reports N2 - It has been shown that muscle fascicle curvature increases with increasing contraction level and decreasing muscle–tendon complex length. The analyses were done with limited examination windows concerning contraction level, muscle–tendon complex length, and/or intramuscular position of ultrasound imaging. With this study we aimed to investigate the correlation between fascicle arching and contraction, muscle–tendon complex length and their associated architectural parameters in gastrocnemius muscles to develop hypotheses concerning the fundamental mechanism of fascicle curving. Twelve participants were tested in five different positions (90°/105°*, 90°/90°*, 135°/90°*, 170°/90°*, and 170°/75°*; *knee/ankle angle). They performed isometric contractions at four different contraction levels (5%, 25%, 50%, and 75% of maximum voluntary contraction) in each position. Panoramic ultrasound images of gastrocnemius muscles were collected at rest and during constant contraction. Aponeuroses and fascicles were tracked in all ultrasound images and the parameters fascicle curvature, muscle–tendon complex strain, contraction level, pennation angle, fascicle length, fascicle strain, intramuscular position, sex and age group were analyzed by linear mixed effect models. Mean fascicle curvature of the medial gastrocnemius increased with contraction level (+5 m−1 from 0% to 100%; p = 0.006). Muscle–tendon complex length had no significant impact on mean fascicle curvature. Mean pennation angle (2.2 m−1 per 10°; p < 0.001), inverse mean fascicle length (20 m−1 per cm−1; p = 0.003), and mean fascicle strain (−0.07 m−1 per +10%; p = 0.004) correlated with mean fascicle curvature. Evidence has also been found for intermuscular, intramuscular, and sex-specific intramuscular differences of fascicle curving. Pennation angle and the inverse fascicle length show the highest predictive capacities for fascicle curving. Due to the strong correlations between pennation angle and fascicle curvature and the intramuscular pattern of curving we suggest for future studies to examine correlations between fascicle curvature and intramuscular fluid pressure. KW - biomechanics KW - connective tissue KW - physiology KW - ultrasound Y1 - 2023 U6 - http://dx.doi.org/10.14814/phy2.15739 SN - 2051-817X VL - 11 IS - 11 SP - e15739, Seite 1-11 PB - Wiley 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 - 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 - JOUR A1 - Capri, Miriam A1 - Morsiani, Cristina A1 - Santoro, Aurelia A1 - Moriggi, Manuela A1 - Conte, Maria A1 - Martucci, Morena A1 - Bellavista, Elena A1 - Fabbri, Cristina A1 - Giampieri, Enrico A1 - Albracht, Kirsten A1 - Flück, Martin A1 - Ruoss, Severin A1 - Brocca, Lorenza A1 - Canepari, Monica A1 - Longa, Emanuela A1 - Giulio, Irene Di A1 - Bottinelli, Roberto A1 - Cerretelli, Paolo A1 - Salvioli, Stefano A1 - Gelfi, Cecilia A1 - Franceschi, Claudio A1 - Narici, Marco A1 - Rittweger, Jörn T1 - Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting JF - The FASEB journal : official publication of the Federation of American Societies for Experimental Biology Y1 - 2019 U6 - http://dx.doi.org/10.1096/fj.201801625R VL - 33 IS - 4 SP - 5168 EP - 5180 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 - GEN A1 - Blottner, Dieter A1 - Hastermann, Maria A1 - Muckelt, Paul A1 - Albracht, Kirsten A1 - Schoenrock, Britt A1 - Salanova, Michele A1 - Warner, Martin A1 - Gunga, Hans-Christian A1 - Stokes, Maria T1 - MYOTONES - Inflight muscle health status monitoring during long-duration space missions onboard the International Space Station: a single case study T2 - IAC Papers Archive N2 - The MYOTONES experiment is the first to monitor changes in the basic biomechanical properties (tone, elasticity and stiffness) of the resting human myofascial system due to microgravity with a oninvasive, portable device on board the ISS. The MyotonPRO device applies several brief mechanical stimuli to the surface of the skin, and the natural oscillation signals of the tissue beneath are detected and computed by the MyotonPRO. Thus, an objective, quick and easy determination of the state of the underlying tissue is possible. Two preflight, four inflight and four post flight measurements were performed on a male astronaut using the same 10 measurement points (MP) for each session. MPs were located on the plantar fascia, Achilles tendon, M. soleus, M. gastrocnemius, M. multifidus, M. splenius capitis, M. deltoideus anterior, M. rectus femoris, infrapatellar tendon, M. tibialis anterior. Subcutaneous tissues thickness above the MPs was measured using ultrasound imaging. Magnetic resonance images (MRI) of lower limb muscles and functional tests were also performed pre- and postflight. Our first measurements on board the ISS confirmed increased tone and stiffness of the lumbar multifidus muscle, an important trunk stabilizer, dysfunction of which is known to be associated with back pain. Furthermore, reduced tone and stiffness of Achilles tendon and plantar fascia were observed inflight vs. preflight, confirming previous findings from terrestrial analog studies and parabolic flights. Unexpectedly, the deltoid showed negative inflight changes in tone and stiffness, and increased elasticity, suggesting a potential risk of muscle atrophy in longer spaceflight that should be addressed by adequate inflight countermeasure protocols. Most values from limb and back MPS showed deflected patterns (in either directions) from inflight shortly after the re-entry phase on the landing day and one week later. Most parameter values then normalized to baseline after 3 weeks likely due to 1G re-adaptation and possible outcome of the reconditioning protocol. No major changes in subcutaneous tissues thickness above the MPs were found inflight vs preflight, suggesting no bias (i.e., fluid shift, extreme tissue thickening or loss). Pre- and postflight MRI and functional tests showed negligible changes in calf muscle size, power and force, which is likely due to training effects from current inflight exercise protocols. The MYOTONES experiment is currently ongoing to collect data from further crew members. The potential impact of this research is to better understand the effects of microgravity and countermeasures over the time course of an ISS mission cycle. This will enable exercise countermeasures to be tailored Y1 - 2019 SN - 00741795 N1 - International Astronautical Congress: space: the power of the past, the promise of the future - Washington DC, USA/Vereinigte Staaten von Amerika Dauer: 21.10.2019 → 25.10.2019 PB - Pergamon CY - Oxford 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 - 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 - 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 - 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 -