@article{OezkanFikriKırkıcıetal.2020, author = {{\"O}zkan, Ay{\c{s}}eg{\"u}l and Fikri, Figen Beken and K{\i}rk{\i}c{\i}, Bilal and Kliegl, Reinhold and Acart{\"u}rk, Cengiz}, title = {Eye movement control in Turkish sentence reading}, series = {Quarterly journal of experimental psychology : QJEP / EPS, Experimental Psychology Society}, volume = {74}, journal = {Quarterly journal of experimental psychology : QJEP / EPS, Experimental Psychology Society}, number = {2}, publisher = {Sage Publ.}, address = {London}, issn = {1747-0218}, doi = {10.1177/1747021820963310}, pages = {377 -- 397}, year = {2020}, abstract = {Reading requires the assembly of cognitive processes across a wide spectrum from low-level visual perception to high-level discourse comprehension. One approach of unravelling the dynamics associated with these processes is to determine how eye movements are influenced by the characteristics of the text, in particular which features of the words within the perceptual span maximise the information intake due to foveal, spillover, parafoveal, and predictive processing. One way to test the generalisability of current proposals of such distributed processing is to examine them across different languages. For Turkish, an agglutinative language with a shallow orthography-phonology mapping, we replicate the well-known canonical main effects of frequency and predictability of the fixated word as well as effects of incoming saccade amplitude and fixation location within the word on single-fixation durations with data from 35 adults reading 120 nine-word sentences. Evidence for previously reported effects of the characteristics of neighbouring words and interactions was mixed. There was no evidence for the expected Turkish-specific morphological effect of the number of inflectional suffixes on single-fixation durations. To control for word-selection bias associated with single-fixation durations, we also tested effects on word skipping, single-fixation, and multiple-fixation cases with a base-line category logit model, assuming an increase of difficulty for an increase in the number of fixations. With this model, significant effects of word characteristics and number of inflectional suffixes of foveal word on probabilities of the number of fixations were observed, while the effects of the characteristics of neighbouring words and interactions were mixed.}, language = {en} } @article{ZuurLundbyeJensenLeukeletal.2010, author = {Zuur, Abraham T. and Lundbye-Jensen, Jesper and Leukel, Christan and Taube, Wolfgang and Grey, Michael J. and Gollhofer, Albert and Nielsen, Jens Bo and Gruber, Markus}, title = {Contribution of afferent feedback and descending drive to human hopping}, issn = {0022-3751}, doi = {10.1113/jphysiol.2009.182709}, year = {2010}, abstract = {During hopping an early burst can be observed in the EMG from the soleus muscle starting about 45 ms after touch-down. It may be speculated that this early EMG burst is a stretch reflex response superimposed on activity from a supra-spinal origin. We hypothesised that if a stretch reflex indeed contributes to the early EMG burst, then advancing or delaying the touch-down without the subject's knowledge should similarly advance or delay the burst. This was indeed the case when touch-down was advanced or delayed by shifting the height of a programmable platform up or down between two hops and this resulted in a correspondent shift of the early EMG burst. Our second hypothesis was that the motor cortex contributes to the first EMG burst during hopping. If so, inhibition of the motor cortex would reduce the magnitude of the burst. By applying a low-intensity magnetic stimulus it was possible to inhibit the motor cortex and this resulted in a suppression of the early EMG burst. These results suggest that sensory feedback and descending drive from the motor cortex are integrated to drive the motor neuron pool during the early EMG burst in hopping. Thus, simple reflexes work in concert with higher order structures to produce this repetitive movement.}, language = {en} } @article{ZinkeGebelGranacheretal.2019, author = {Zinke, Fridolin and Gebel, Arnd and Granacher, Urs and Prieske, Olaf}, title = {Acute Effects of Short-Term Local Tendon Vibration on Plantar Flexor Torque, Muscle Contractile Properties, Neuromuscular and Brain Activity in Young Athletes}, series = {Journal of sports science \& medicine}, volume = {18}, journal = {Journal of sports science \& medicine}, number = {2}, publisher = {Department of Sports Medicine, Medical Faculty of Uludag University}, address = {Bursa}, issn = {1303-2968}, pages = {327 -- 336}, year = {2019}, abstract = {The purpose of this study was to examine the acute effects of short-term Achilles tendon vibration on plantar flexor torque, twitch contractile properties as well as muscle and cortical activity in young athletes. Eleven female elite soccer players aged 15.6 +/- 0.5 years participated in this study. Three different conditions were applied in randomized order: Achilles tendon vibration (80 Hz) for 30 and 300 s, and a passive control condition (300 s). Tests at baseline and following conditions included the assessment of peak plantar flexor torque during maximum voluntary contraction, electrically evoked muscle twitches (e.g., potentiated twitch peak torque [PT]), and electromyographic (EMG) activity of the plantar flexors. Additionally, electroencephalographic (EEG) activity of the primary motor and somatosensory cortex were assessed during a submaximal dynamic concentric-eccentric plantar flexion exercise using an elastic rubber band. Large-sized main effects of condition were found for EEG absolute alpha-1 and beta-1 band power (p <= 0.011; 1.5 <= d <= 2.6). Post-hoc tests indicated that alpha-1 power was significantly lower at 30 and 300 s (p = 0.009; d = 0.8) and beta-1 power significantly lower at 300 s (p < 0.001; d = 0.2) compared to control condition. No significant effect of condition was found for peak plantar flexor torque, electrical evoked muscle twitches, and EMG activity. In conclusion, short-term local Achilles tendon vibration induced lower brain activity (i.e., alpha-1 and beta-1 band power) but did not affect lower limb peak torque, twitch contractile properties, and muscle activity. Lower brain activity following short-term local Achilles tendon vibration may indicate improved cortical function during a submaximal dynamic exercise in female young soccer players.}, language = {en} } @article{ZieglerEhrlenspielBrand2009, author = {Ziegler, Matthias and Ehrlenspiel, Felix and Brand, Ralf}, title = {Latent state-trait theory : an application in sport psychology}, issn = {1469-0292}, doi = {10.1016/j.psychsport.2008.12.004}, year = {2009}, abstract = {Objective: Questionnaires are often applied in sports psychology to measure a person's trait or state. However, the extent to which the questionnaire captures differences because of trait or state influences is often unclear. The latent state-trait (LST) theory offers the opportunity to separate both variance sources. This separation allows estimating specific reliability coefficients. Design: The present paper gives a theoretical introduction to LST and its basic ideas. Using a real data set with N = 156 athletes we exemplify the steps necessary to derive the LST coefficients. All athletes filled out a comprehensive inventory assessing competitive anxiety on two occasions. Method: The data are analysed with structural equation models based on LST principles. Results: The results confirm the questionnaire's trait saturation. Conclusion: Finally, results are discussed in light of practical and theoretical implications.}, language = {en} } @article{ZhangSaidWischkeetal.2017, author = {Zhang, Nan and Said, Andre and Wischke, Christian and Kral, Vivian and Brodwolf, Robert and Volz, Pierre and Boreham, Alexander and Gerecke, Christian and Li, Wenzhong and Neffe, Axel T. and Kleuser, Burkhard and Alexiev, Ulrike and Lendlein, Andreas and Sch{\"a}fer-Korting, Monika}, title = {Poly[acrylonitrile-co-(N-vinyl pyrrolidone)] nanoparticles - Composition-dependent skin penetration enhancement of a dye probe and biocompatibility}, series = {European Journal of Pharmaceutics and Biopharmaceutics}, volume = {116}, journal = {European Journal of Pharmaceutics and Biopharmaceutics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0939-6411}, doi = {10.1016/j.ejpb.2016.10.019}, pages = {66 -- 75}, year = {2017}, abstract = {Nanoparticles can improve topical drug delivery: size, surface properties and flexibility of polymer nanoparticles are defining its interaction with the skin. Only few studies have explored skin penetration for one series of structurally related polymer particles with systematic alteration of material composition. Here, a series of rigid poly[acrylonitrile-co-(N-vinyl pyrrolidone)] model nanoparticles stably loaded with Nile Red or Rhodamin B, respectively, was comprehensively studied for biocompatibility and functionality. Surface properties were altered by varying the molar content of hydrophilic NVP from 0 to 24.1\% and particle size ranged from 35 to 244 nm. Whereas irritancy and genotoxicity were not revealed, lipophilic and hydrophilic nanoparticles taken up by keratinocytes affected cell viability. Skin absorption of the particles into viable skin ex vivo was studied using Nile Red as fluorescent probe. Whilst an intact stratum corneum efficiently prevented penetration, almost complete removal of the horny layer allowed nanoparticles of smaller size and hydrophilic particles to penetrate into viable epidermis and dermis. Hence, systematic variations of nanoparticle properties allows gaining insights into critical criteria for biocompatibility and functionality of novel nanocarriers for topical drug delivery and risks associated with environmental exposure.}, language = {en} } @article{ZechSchuchPerezChaparroetal.2020, author = {Zech, Philipp and Schuch, Felipe and P{\´e}rez Chaparro, Camilo Germ{\´a}n Alberto and Kangas, Maria and Rapp, Michael Armin and Heissel, Andreas}, title = {Exercise, Comorbidities, and Health-Related Quality of Life in People Living with HIV}, series = {International Journal of Environmental Research and Public Health}, volume = {17}, journal = {International Journal of Environmental Research and Public Health}, number = {14}, publisher = {MDPI AG}, address = {Basel}, issn = {1660-4601}, doi = {10.3390/ijerph17145138}, pages = {15}, year = {2020}, abstract = {(1) Background: People with HIV (PWH) may perform more than one type of exercise cumulatively. The objective of this study is to investigate recreational exercise and its association with health-related quality of life (HRQOL) and comorbidities in relation to potential covariates. (2) Methods: The HIBES study (HIV-Begleiterkrankungen-Sport) is a cross-sectional study for people with HIV. The differences between non-exercisers versus exercisers (cumulated vs. single type of exercises) were investigated using regression models based on 454 participants. (3) Results: Exercisers showed a higher HRQOL score compared to non-exercisers (Wilcox r = 0.2 to 0.239). Psychological disorders were identified as the main covariate. Participants performing exercise cumulatively showed higher scores in duration, frequency, and intensity when compared to participants performing only one type of exercise. The mental health summary score was higher for the cumulated and single type of exercise if a psychological disorder existed. Duration and intensity were associated with an increase of HRQOL, whilst a stronger association between psychological disorders and exercise variables were evident. Exercise duration (minutes) showed a significant effect on QOL (standardized beta = 0.1) and for participants with psychological disorders (standardized beta = 0.3), respectively. (4) Conclusions: Psychological disorders and other covariates have a prominent effect on HRQOL and its association with exercise. For PWH with a psychological disorder, a stronger relationship between HRQOL with exercise duration and intensity emerged. However, differentiation of high-HRQOL individuals warrants further investigation by considering additional factors.}, language = {en} } @article{ZechPerezChaparroSchuchetal.2019, author = {Zech, Philipp and Perez Chaparro, Camilo Germ{\´a}n Alberto and Schuch, Felipe and Wolfarth, Bernd and Rapp, Michael Armin and Heissel, Andreas}, title = {Effects of Aerobic and Resistance Exercise on Cardiovascular Parameters for People Living With HIV}, series = {JANAC-Journal of the Association of Nurses in AIDS Care}, volume = {30}, journal = {JANAC-Journal of the Association of Nurses in AIDS Care}, number = {2}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1055-3290}, doi = {10.1097/JNC.0000000000000006}, pages = {186 -- 205}, year = {2019}, abstract = {People living with HIV (PLWH) have limited exercise capacity because of anemia, neuromuscular disorders, and pulmonary limitations. We used a meta-analysis to examine the effect of aerobic and resistance exercise alone and in combination on cardiovascular parameters. Subgroup meta-analyses were conducted and long-term effects of exercise were investigated. A systematic literature search was conducted up to July/August 2017. The Physiotherapy Evidence Database-scale was used to rate quality and assess the risk of bias on the papers. Standardized mean differences (SMDs) were calculated to assess the effect of exercise. Posttreatment comparison between the exercise and control groups revealed moderate and large effect sizes in favor of the intervention group for VO2max (SMD50.66, p < .0001) and the 6-minute walk test (SMD = 1.11, p = .0001). Exercise had a positive effect on cardiovascular parameters in PLWH. Exercise can be a prevention factor for PLWH dealing with multiple comorbidities.}, language = {en} } @article{ZaytsevaKorsakovaGurovichetal.2014, author = {Zaytseva, Yuliya and Korsakova, Natalya and Gurovich, Isaac Ya and Heinz, Andreas and Rapp, Michael Armin}, title = {Luria revisited: Complex motor phenomena in first episode schizophrenia and schizophrenia spectrum disorders}, series = {Psychiatry research : the official publication of the International Society for Neuroimaging in Psychiatry}, volume = {220}, journal = {Psychiatry research : the official publication of the International Society for Neuroimaging in Psychiatry}, number = {1-2}, publisher = {Elsevier}, address = {Clare}, issn = {0165-1781}, doi = {10.1016/j.psychres.2014.08.009}, pages = {145 -- 151}, year = {2014}, language = {en} } @article{WyckmansOttoSeboldetal.2019, author = {Wyckmans, Florent and Otto, A. Ross and Sebold, Miriam Hannah and Daw, Nathaniel and Bechara, Antoine and Saeremans, M{\´e}lanie and Kornreich, Charles and Chatard, Armand and Jaafari, Nemat and No{\"e}l, Xavier}, title = {Reduced model-based decision-making in gambling disorder}, series = {Scientific reports}, volume = {9}, journal = {Scientific reports}, publisher = {Nature Publ. Group}, address = {London}, issn = {2045-2322}, doi = {10.1038/s41598-019-56161-z}, pages = {10}, year = {2019}, abstract = {Compulsive behaviors (e.g., addiction) can be viewed as an aberrant decision process where inflexible reactions automatically evoked by stimuli (habit) take control over decision making to the detriment of a more flexible (goal-oriented) behavioral learning system. These behaviors are thought to arise from learning algorithms known as "model-based" and "model-free" reinforcement learning. Gambling disorder, a form of addiction without the confound of neurotoxic effects of drugs, showed impaired goal-directed control but the way in which problem gamblers (PG) orchestrate model-based and model-free strategies has not been evaluated. Forty-nine PG and 33 healthy participants (CP) completed a two-step sequential choice task for which model-based and model-free learning have distinct and identifiable trial-by-trial learning signatures. The influence of common psychopathological comorbidities on those two forms of learning were investigated. PG showed impaired model-based learning, particularly after unrewarded outcomes. In addition, PG exhibited faster reaction times than CP following unrewarded decisions. Troubled mood, higher impulsivity (i.e., positive and negative urgency) and current and chronic stress reported via questionnaires did not account for those results. These findings demonstrate specific reinforcement learning and decision-making deficits in behavioral addiction that advances our understanding and may be important dimensions for designing effective interventions.}, language = {en} } @article{WuertzKozakBleischNadietal.2018, author = {Wuertz-Kozak, Karin and Bleisch, Dominique and Nadi, Najia and Proemmel, Peter and Hitzl, Wolfgang and Kessler, Thomas M. M. and Gautschi, Oliver P. and Hausmann, Oliver N.}, title = {Sexual and urinary function following anterior lumbar surgery in females}, series = {Neurourology and urodynamics}, volume = {38}, journal = {Neurourology and urodynamics}, number = {2}, publisher = {Wiley}, address = {Hoboken}, issn = {0733-2467}, doi = {10.1002/nau.23874}, pages = {632 -- 636}, year = {2018}, abstract = {Aims Anterior lumbar interbody fusion procedures (ALIF) and total disc replacement (TDR) with anterior exposure of the lumbar spine entail a risk of a vascular injury and dysfunction of the sympathetic and parasympathetic nerves due to disturbance of the inferior and superior hypogastric plexus. While retrograde ejaculation is a known complication of the anterior spinal approach in males, post-operative sexual as well as urinary function in females has not yet been thoroughly investigated and was hence the aim of this study. Methods Fifteen female patients documented their sexual and urinary function preoperatively, 3 months and 6 months postoperatively, using the validated questionnaires FSFI (Female Sexual Function Index) and ICIQ (International Consultation of Incontinence Questionnaire). Randomization tests were used to statistically analyze expectation values over time (two-sided, P < 0.05). Results While no statistically significant change in the total FSFI score occurred over time, a significant increase in FSFI desire score was noted between preoperative (2.95 +/- 0.8) and 6 months follow-up (3.51 +/- 0.6, P = 0.02). Urinary continence remained unchanged over time. Conclusion In summary, ALIF and lumbar TDR do not seem to negatively influence sexual and urinary function in females. In contrast, increased sexual desire was noted, likely secondary to post-surgical pain relief.}, language = {en} } @article{WolffSchindlerBrand2015, author = {Wolff, Wanja and Schindler, Sebastian and Brand, Ralf}, title = {The Effect of Implicitly Incentivized Faking on Explicit and Implicit Measures of Doping Attitude: When Athletes Want to Pretend an Even More Negative Attitude to Doping}, series = {PLoS one}, volume = {10}, journal = {PLoS one}, number = {4}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0118507}, pages = {10}, year = {2015}, abstract = {The Implicit Association Test (IAT) aims to measure participants' automatic evaluation of an attitude object and is useful especially for the measurement of attitudes related to socially sensitive subjects, e.g. doping in sports. Several studies indicate that IAT scores can be faked on instruction. But fully or semi-instructed research scenarios might not properly reflect what happens in more realistic situations, when participants secretly decide to try faking the test. The present study is the first to investigate IAT faking when there is only an implicit incentive to do so. Sixty-five athletes (22.83 years +/- 2.45; 25 women) were randomly assigned to an incentive-to-fake condition or a control condition. Participants in the incentive-to-fake condition were manipulated to believe that athletes with lenient doping attitudes would be referred to a tedious 45-minute anti-doping program. Attitudes were measured with the pictorial doping brief IAT (BIAT) and with the Performance Enhancement Attitude Scale (PEAS). A one-way MANOVA revealed significant differences between conditions after the manipulation in PEAS scores, but not in the doping BIAT. In the light of our hypothesis this suggests that participants successfully faked an exceedingly negative attitude to doping when completing the PEAS, but were unsuccessful in doing so on the reaction time-based test. This study assessed BIAT faking in a setting that aimed to resemble a situation in which participants want to hide their attempts to cheat. The two measures of attitude were differentially affected by the implicit incentive. Our findings provide evidence that the pictorial doping BIAT is relatively robust against spontaneous and naive faking attempts. (B) IATs might be less prone to faking than implied by previous studies.}, language = {en} } @article{WolffBrand2013, author = {Wolff, Wanja and Brand, Ralf}, title = {Subjective stressors in school and their relation to neuroenhancement a behavioral perspective on students' everyday life "doping"}, series = {Substance abuse treatment, prevention, and policy}, volume = {8}, journal = {Substance abuse treatment, prevention, and policy}, publisher = {BioMed Central}, address = {London}, issn = {1747-597X}, doi = {10.1186/1747-597X-8-23}, pages = {6}, year = {2013}, abstract = {Background: The use of psychoactive substances to neuroenhance cognitive performance is prevalent. Neuroenhancement (NE) in everyday life and doping in sport might rest on similar attitudinal representations, and both behaviors can be theoretically modeled by comparable means-to-end relations (substance-performance). A behavioral (not substance-based) definition of NE is proposed, with assumed functionality as its core component. It is empirically tested whether different NE variants (lifestyle drug, prescription drug, and illicit substance) can be regressed to school stressors. Findings: Participants were 519 students (25.8 +/- 8.4 years old, 73.1\% female). Logistic regressions indicate that a modified doping attitude scale can predict all three NE variants. Multiple NE substance abuse was frequent. Overwhelming demands in school were associated with lifestyle and prescription drug NE. Conclusions: Researchers should be sensitive for probable structural similarities between enhancement in everyday life and sport and systematically explore where findings from one domain can be adapted for the other. Policy makers should be aware that students might misperceive NE as an acceptable means of coping with stress in school, and help to form societal sensitivity for the topic of NE among our younger ones in general.}, language = {en} } @article{WojcinskiDupontSchmidtetal.2012, author = {Wojcinski, Sebastian and Dupont, Jennifer and Schmidt, Werner and Cassel, Michael and Hillemanns, Peter}, title = {Real-time ultrasound elastography in 180 axillary lymph nodes elasticity distribution in healthy lymph nodes and prediction of breast cancer metastases}, series = {BMC medical imaging}, volume = {12}, journal = {BMC medical imaging}, publisher = {BioMed Central}, address = {London}, issn = {1471-2342}, doi = {10.1186/1471-2342-12-35}, pages = {10}, year = {2012}, abstract = {Background: To determine the general appearance of normal axillary lymph nodes (LNs) in real-time tissue sonoelastography and to explore the method's potential value in the prediction of LN metastases. Methods: Axillary LNs in healthy probands (n=165) and metastatic LNs in breast cancer patients (n=15) were examined with palpation, B-mode ultrasound, Doppler and sonoelastography (assessment of the elasticity of the cortex and the medulla). The elasticity distributions were compared and sensitivity (SE) and specificity (SP) were calculated. In an exploratory analysis, positive and negative predictive values (PPV, NPV) were calculated based upon the estimated prevalence of LN metastases in different risk groups. Results: In the elastogram, the LN cortex was significantly harder than the medulla in both healthy (p=0.004) and metastatic LNs (p=0.005). Comparing healthy and metastatic LNs, there was no difference in the elasticity distribution of the medulla (p=0.281), but we found a significantly harder cortex in metastatic LNs (p=0.006). The SE of clinical examination, B-mode ultrasound, Doppler ultrasound and sonoelastography was revealed to be 13.3\%, 40.0\%, 14.3\% and 60.0\%, respectively, and SP was 88.4\%, 96.8\%, 95.6\% and 79.6\%, respectively. The highest SE was achieved by the disjunctive combination of B-mode and elastographic features (cortex >3mm in B-mode or blue cortex in the elastogram, SE=73.3\%). The highest SP was achieved by the conjunctive combination of B-mode ultrasound and elastography (cortex >3mm in B-mode and blue cortex in the elastogram, SP=99.3\%). Conclusions: Sonoelastography is a feasible method to visualize the elasticity distribution of LNs. Moreover, sonoelastography is capable of detecting elasticity differences between the cortex and medulla, and between metastatic and healthy LNs. Therefore, sonoelastography yields additional information about axillary LN status and can improve the PPV, although this method is still experimental.}, language = {en} } @article{WojcinskiCasselFarrokhetal.2012, author = {Wojcinski, Sebastian and Cassel, Michael and Farrokh, Andre and Soliman, Amr A. and Hille, Ursula and Schmidt, Werner and Degenhardt, Friedrich and Hillemanns, Peter}, title = {Variations in the elasticity of breast tissue during the menstrual cycle determined by real-time sonoelastography}, series = {Journal of ultrasound in medicine}, volume = {31}, journal = {Journal of ultrasound in medicine}, number = {1}, publisher = {American Institute of Ultrasound in Medicine}, address = {Laurel}, issn = {0278-4297}, pages = {63 -- 72}, year = {2012}, abstract = {Objectives-The purpose of this study was to determine the dependence of breast tissue elasticity on the menstrual cycle of healthy volunteers by means of real-time sonoelastography. Methods-Twenty-two healthy volunteers (aged 18-33 years) were examined once weekly during two consecutive menstrual cycles using sonoelastography. Group 1 (n = 10) was not taking hormonal medication; group 2 (n = 12) was taking oral contraceptives. Results-The breast parenchyma appeared softer than the dermis and harder than the adipose tissue, and elasticity varied over the menstrual cycle and between groups. Group 1 (no hormone intake) showed continuously increasing elasticity with relatively soft breast parenchyma in the menstrual and follicular phases and harder parenchyma in the luteal phase (P = .012). Group 2 (oral contraceptives) showed no statistically significant changes in breast parenchymal elasticity according to sonoelastography. The parenchyma was generally softer in group 1 compared with group 2 throughout the menstrual cycle (P = .033). The dermis, the subcutaneous adipose tissue, and the pectoralis major muscle showed no changes in elasticity. Comparison of measurements made during the first and the second menstrual cycles showed similar patterns of elasticity in both groups. Conclusions-Sonoelastography is a reproducible method that can be used to determine the dependence of breast parenchyma elasticity on the menstrual cycle and on the intake of hormonal contraceptives.}, language = {en} } @article{WochatzTilgnerMuelleretal.2019, author = {Wochatz, Monique and Tilgner, Nina and Mueller, Steffen and Rabe, Sophie and Eichler, Sarah and John, Michael and V{\"o}ller, Heinz and Mayer, Frank}, title = {Reliability and validity of the Kinect V2 for the assessment of lower extremity rehabilitation exercises}, series = {Gait \& posture}, volume = {70}, journal = {Gait \& posture}, publisher = {Elsevier}, address = {Clare}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2019.03.020}, pages = {330 -- 335}, year = {2019}, abstract = {Research question: The purpose of this study was to evaluate the test-retest reliability of lower extremity kinematics during squat, hip abduction and lunge exercises captured by the Kinect and to evaluate the agreement to a reference 3D camera-based motion system. Methods: Twenty-one healthy individuals performed five repetitions of each lower limb exercise on two different days. Movements were simultaneously assessed by the Kinect and the reference 3D motion system. Joint angles and positions of the lower limb were calculated for sagittal and frontal plane. For the inter-session reliability and the agreement between the two systems standard error of measurement (SEM), bias with limits of agreement (LoA) and Pearson Correlation Coefficient (r) were calculated. Results: Parameters indicated varying reliability for the assessed joint angles and positions and decreasing reliability with increasing task complexity. Across all exercises, measurement deviations were shown especially for small movement amplitudes. Variability was acceptable for joint angles and positions during the squat, partially acceptable during the hip abduction and predominately inacceptable during the lunge. The agreement between systems was characterized by systematic errors. Overestimations by the Kinect were apparent for hip flexion during the squat and hip abduction/adduction during the hip abduction exercise as well as for the knee positions during the lunge. Knee and hip flexion during hip abduction and lunge were underestimated by the Kinect. Significance: The Kinect system can reliably assess lower limb joint angles and positions during simple exercises. The validity of the system is however restricted. An application in the field of early orthopedic rehabilitation without further development of post-processing techniques seems so far limited.}, language = {en} } @article{WochatzRabeWolteretal.2017, author = {Wochatz, Monique and Rabe, Sophie and Wolter, Martin and Engel, Tilman and Mueller, Steffen and Mayer, Frank}, title = {Reproducibility of scapular muscle activity in isokinetic shoulder flexion and extension}, series = {Journal of electromyography and kinesiology}, volume = {34}, journal = {Journal of electromyography and kinesiology}, publisher = {Elsevier}, address = {Oxford}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2017.04.006}, pages = {86 -- 92}, year = {2017}, abstract = {Repetitive overhead movements have been identified as a main risk factor to develop shoulder complaints with scapular muscle activity being altered. Reliable assessment of muscle activity is essential to differentiate between symptomatic and asymptomatic individuals. Therefore, the present study aimed to investigate the intra-and inter-session reliability of scapular muscle activity during maximal isokinetic shoulder flexion and extension. Eleven asymptomatic adults performed maximum effort isokinetic shoulder flexion and extension (concentric and eccentric at 60 degrees/s) in a test-retest design. Muscle activity of the upper and lower trapezius and serratus anterior was assessed by sEMG. Root Mean Square was calculated for whole ROM and single movement phases of absolute and normalized muscle activity. Absolute (Bland-Altman analysis (Bias, LoA), Minimal detectable change (MDC)) and relative reliability parameters (Intraclass correlation coefficient (ICC), coefficient of variation (CV)/test-retest variability (TRV)) were utilized for the evaluation of reproducibility. Intra-session reliability revealed ICCs between 0.56 and 0.98, averaged CVs of 18\% and average MDCs of 81 mV. Inter-session reliability resulted in ICCs between 0.13 and 0.93, averaged TRVs of 21\%, average MDCs of 15\% and systematic and random error between -8 +/- 60\% and 12 +/- 36\%. Scapular muscle activity assessed in overhead movements can be measured reliably under maximum load conditions, though variability is dependent on the movement phase. Measurement variability does not exceed magnitudes of altered scapular muscle activities as reported in previous studies. Therefore, maximum load application is a promising approach for the evaluation of changes in scapular control related to pathologies. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{WochatzRabeWolteretal.2017, author = {Wochatz, Monique and Rabe, Sophie and Wolter, Martin and Engel, Tilman and Mueller, Steffen and Mayer, Frank}, title = {Muscle activity of upper and lower trapezius and serratus anterior during unloaded and maximal loaded shoulder flexion and extension}, series = {International Biomechanics}, volume = {4}, journal = {International Biomechanics}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, doi = {https://doi.org/10.1080/23335432.2017.1364668}, pages = {68 -- 76}, year = {2017}, abstract = {Altered scapular muscle activity is mostly described under unloaded and submaximal loaded conditions in impingement patients. However, there is no clear evidence on muscle activity with respect to movement phases under maximum load in healthy subjects. Therefore, this study aimed to investigate scapular muscle activity under unloaded and maximum loaded isokinetic shoulder flexion and extension in regard to the movement phase. Fourteen adults performed unloaded (continuous passive motion [CPM]) as well as maximum loaded (concentric [CON], eccentric [ECC]) isokinetic shoulder flexion (Flex) and extension (Ext). Simultaneously, scapular muscle activity was measured by EMG. Root mean square was calculated for the whole ROM and four movement phases. Data were analyzed descriptively and by two-way repeated measures ANOVA. CPMFlex resulted in a linear increase of muscle activity for all muscles. Muscle activity during CONFlex and ECCFlex resulted in either constant activity levels or in an initial increase followed by a plateau in the second half of movement. CPMExt decreased with the progression of movement, whereas CONExt and ECCExt initially decreased and either levelled off or increased in the second half of movement. Scapular muscle activity of unloaded shoulder flexion and extension changed under maximum load showing increased activity levels and an altered pattern over the course of movement.}, language = {en} } @article{WochatzRabeEngeletal.2021, author = {Wochatz, Monique and Rabe, Sophie and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank}, title = {Scapular kinematics during unloaded and maximal loaded isokinetic concentric and eccentric shoulder flexion and extension movements}, series = {Journal of electromyography \& kinesiology : official journal of the International Society of Electrophysiology and Kinesiology}, volume = {57}, journal = {Journal of electromyography \& kinesiology : official journal of the International Society of Electrophysiology and Kinesiology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1050-6411}, doi = {10.1016/j.jelekin.2021.102517}, pages = {8}, year = {2021}, abstract = {Characterization of scapular kinematics under demanding load conditions might aid to distinguish between physiological and clinically relevant alterations. Previous investigations focused only on submaximal external load situations. How scapular movement changes with maximal load remains unclear. Therefore, the present study aimed to evaluate 3D scapular kinematics during unloaded and maximal loaded shoulder flexion and extension. Twelve asymptomatic individuals performed shoulder flexion and extension movements under unloaded and maximal concentric and eccentric loaded isokinetic conditions. 3D scapular kinematics assessed with a motion capture system was analyzed for 20° intervals of humeral positions from 20° to 120° flexion. Repeated measures ANOVAs were used to evaluate kinematic differences between load conditions for scapular position angles, scapulohumeral rhythm and scapular motion extent. Increased scapular upward rotation was seen during shoulder flexion and extension as well as decreased posterior tilt and external rotation during eccentric and concentric arm descents of maximal loaded compared to unloaded conditions. Load effects were further seen for the scapulohumeral rhythm with greater scapular involvement at lower humeral positions and increased scapular motion extent under maximal loaded shoulder movements. With maximal load applied to the arm physiological scapular movement pattern are induced that may imply both impingement sparing and causing mechanisms.}, language = {en} } @article{WochatzEngelMuelleretal.2020, author = {Wochatz, Monique and Engel, Tilman and M{\"u}ller, Steffen and Mayer, Frank}, title = {Alterations in scapular kinematics and scapular muscle activity after fatiguing shoulder flexion and extension movements}, series = {Medicine and science in sports and exercise : MSSE}, volume = {52}, journal = {Medicine and science in sports and exercise : MSSE}, number = {17}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {0195-9131}, doi = {10.1249/01.mss.0000676540.02017.2c}, pages = {274 -- 274}, year = {2020}, abstract = {Repetitive overhead motions in combination with heavy loading were identified as risk factors for the development of shoulder pain. However, the underlying mechanism is not fully understood. Altered scapular kinematics as a result of muscle fatigue is suspected to be a contributor. PURPOSE: To determine scapular kinematics and scapular muscle activity at the beginning and end of constant shoulder flexion and extension loading in asymptomatic individuals. METHODS: Eleven asymptomatic adults (28±4yrs; 1.74±0.13m; 74±16kg) underwent maximum isokinetic loading of shoulder flexion (FLX) and extension (EXT) in the sagittal plane (ROM: 20- 180°; concentric mode; 180°/s) until individual peak torque was reduced by 50\%. Simultaneously 3D scapular kinematics were assessed with a motion capture system and scapular muscle activity with a 3-lead sEMG of upper and lower trapezius (UT, LT) and serratus anterior (SA). Scapular position angles were calculated for every 20° increment between 20-120° humerothoracic positions. Muscle activity was quantified by amplitudes (RMS) of the total ROM. Descriptive analyses (mean±SD) of kinematics and muscle activity at begin (taskB) and end (taskE) of the loading task was followed by ANOVA and paired t-tests. RESULTS: At taskB activity ranged from 589±343mV to 605±250mV during FLX and from 105±41mV to 164±73mV during EXT across muscles. At taskE activity ranged from 594±304mV to 875±276mV during FLX and from 97±33mV to 147±57mV during EXT. Differences with increased muscle activity were seen for LT and UT during FLX (meandiff= 141±113mV for LT, p<0.01; 191±153mV for UT, p<0.01). Scapula position angles continuously increased in upward rotation, posterior tilt and external rotation during FLX and reversed during EXT both at taskB and taskE. At taskE scapula showed greater external rotation (meandiff= 3.6±3.7°, p<0.05) during FLX and decreased upward rotation (meandiff= 1.9±2.3°, p<0.05) and posterior tilt (meandiff= 1.0±2.1°, p<0.05) during EXT across humeral positions. CONCLUSIONS: Force reduction in consequence of fatiguing shoulder loading results in increased scapular muscle activity and minor alterations in scapula motion. Whether even small changes have a clinical impact by creating unfavorable subacromial conditions potentially initiating pain remains unclear.}, language = {en} } @article{WippertPuschmannArampatzisetal.2017, author = {Wippert, Pia-Maria and Puschmann, Anne-Katrin and Arampatzis, Adamantios and Schiltenwolf, Marcus and Mayer, Frank}, title = {Diagnosis of psychosocial risk factors in prevention of low back pain in athletes (MiSpEx)}, series = {BMJ Open Sport \& Exercise Medicine}, volume = {3}, journal = {BMJ Open Sport \& Exercise Medicine}, number = {1}, issn = {2055-7647}, doi = {10.1136/bmjsem-2017-000295}, year = {2017}, abstract = {Background Low back pain (LBP) is a common pain syndrome in athletes, responsible for 28\% of missed training days/year. Psychosocial factors contribute to chronic pain development. This study aims to investigate the transferability of psychosocial screening tools developed in the general population to athletes and to define athlete-specific thresholds. Methods Data from a prospective multicentre study on LBP were collected at baseline and 1-year follow-up (n=52 athletes, n=289 recreational athletes and n=246 non-athletes). Pain was assessed using the Chronic Pain Grade questionnaire. The psychosocial Risk Stratification Index (RSI) was used to obtain prognostic information regarding the risk of chronic LBP (CLBP). Individual psychosocial risk profile was gained with the Risk Prevention Index - Social (RPI-S). Differences between groups were calculated using general linear models and planned contrasts. Discrimination thresholds for athletes were defined with receiver operating characteristics (ROC) curves. Results Athletes and recreational athletes showed significantly lower psychosocial risk profiles and prognostic risk for CLBP than non-athletes. ROC curves suggested discrimination thresholds for athletes were different compared with non-athletes. Both screenings demonstrated very good sensitivity (RSI=100\%; RPI-S: 75\%-100\%) and specificity (RSI: 76\%-93\%; RPI-S: 71\%-93\%). RSI revealed two risk classes for pain intensity (area under the curve (AUC) 0.92(95\% CI 0.85 to 1.0)) and pain disability (AUC 0.88(95\% CI 0.71 to 1.0)). Conclusions Both screening tools can be used for athletes. Athlete-specific thresholds will improve physicians' decision making and allow stratified treatment and prevention.}, language = {en} }