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Background:
Deception can distort psychological tests on socially sensitive topics. Understanding the cerebral
processes that are involved in such faking can be useful in detection and prevention of deception. Previous research
shows that faking a brief implicit association test (BIAT ) evokes a characteristic ERP response. It is not yet known
whether temporarily available self-control resources moderate this response. We randomly assigned 22 participants
(15 females, 24.23
±
2.91
years old) to a counterbalanced repeated-measurements design. Participants first com-
pleted a Brief-IAT (BIAT ) on doping attitudes as a baseline measure and were then instructed to fake a negative dop
-
ing attitude both when self-control resources were depleted and non-depleted. Cerebral activity during BIAT perfor
-
mance was assessed using high-density EEG.
Results:
Compared to the baseline BIAT, event-related potentials showed a first interaction at the parietal P1,
while significant post hoc differences were found only at the later occurring late positive potential. Here, signifi-
cantly decreased amplitudes were recorded for ‘normal’ faking, but not in the depletion condition. In source space,
enhanced activity was found for ‘normal’ faking in the bilateral temporoparietal junction. Behaviorally, participants
were successful in faking the BIAT successfully in both conditions.
Conclusions:
Results indicate that temporarily available self-control resources do not affect overt faking success on
a BIAT. However, differences were found on an electrophysiological level. This indicates that while on a phenotypical
level self-control resources play a negligible role in deliberate test faking the underlying cerebral processes are markedly different.
Stumbling led to an increase in ROM, compared to unperturbed gait, in all segments and planes. These increases ranged between 107 +/- 26% (UTA/rotation) and 262 +/- 132% (UTS/lateral flexion), significant only in lateral flexion. EMG activity of the trunk was increased during stumbling (abdominal: 665 +/- 283%; back: 501 +/- 215%), without significant differences between muscles. Provoked stumbling leads to a measurable effect on the trunk, quantifiable by an increase in ROM and EMG activity, compared to normal walking. Greater abdominal muscle activity and ROM of lateral flexion may indicate a specific compensation pattern occurring during stumbling. (C) 2015 Elsevier Ltd. All rights reserved.
The reservoir competence and long life expectancy of edible dormice, Glis glis, suggest that they serve as efficient reservoir hosts for Lyme disease (LD) spirochetes. Their arboreality, however, may reduce the probability to encounter sufficient questing Ixodes ricinus ticks to acquire and perpetuate LD spirochetes. To define the potential role of this small arboreal hibernator in the transmission cycle of LD spirochetes, we examined their rate and density of infestation with subadult ticks throughout the season of activity. Of the 1081 edible dormice that we captured at five study sites in Southern Germany and inspected for ticks at 2946 capture occasions, 26 % were infested with at least one and as many as 26 subadult ticks on their ear pinnae. The distribution of ticks feeding on edible dormice was highly aggregated. Although only few individuals harbored nymphal ticks soon after their emergence from hibernation, the rate of nymphal infestation increased steadily throughout the season and reached about 35 % in September. Dormice inhabiting a site with few conspecifics seemed more likely to be infested by numerous ticks, particularly nymphs, than those individuals living in densely populated sites. Male dormice were more likely to be parasitized by numerous nymphs than were females, independent of their age and body mass. Our observation that season, population density, and sex affect the rates of ticks feeding on edible dormice suggests that the contribution of edible dormice to the transmission cycle of LD spirochetes depends mainly on their ranging behavior and level of activity.
Background: Low back pain (LBP) is one of the world wide leading causes of limited activity and disability. Impaired motor control has been found to be one of the possible factors related to the development or persistence of LBP. In particularly, motor control strategies seemed to be altered in situations requiring reactive responses of the trunk counteracting sudden external forces. However, muscular responses were mostly assessed in (quasi) static testing situations under simplified laboratory conditions. Comprehensive investigations in motor control strategies during dynamic everyday situations are lacking. The present research project aimed to investigate muscular compensation strategies following unexpected gait perturbations in people with and without LBP. A novel treadmill stumbling protocol was tested for its validity and reliability to provoke muscular reflex responses at the trunk and the lower extremities (study 1). Thereafter, motor control strategies in response to sudden perturbations were compared between people with LBP and asymptomatic controls (CTRL) (study 2). In accordance with more recent concepts of motor adaptation to pain, it was hypothesized that pain may have profound consequences on motor control strategies in LBP. Therefore, it was investigated whether differences in compensation strategies were either consisting of changes local to the painful area at the trunk, or also being present in remote areas such as at the lower extremities.
Methods: All investigations were performed on a custom build split-belt treadmill simulating trip-like events by unexpected rapid deceleration impulses (amplitude: 2 m/s; duration: 100 ms; 200 ms after heel contact) at 1m/s baseline velocity. A total number of 5 (study 1) and 15 (study 2) right sided perturbations were applied during walking trials. Muscular activities were assessed by surface electromyography (EMG), recorded at 12 trunk muscles and 10 (study 1) respectively 5 (study 2) leg muscles. EMG latencies of muscle onset [ms] were retrieved by a semi-automatic detection method. EMG amplitudes (root mean square (RMS)) were assessed within 200 ms post perturbation, normalized to full strides prior to any perturbation [RMS%]. Latency and amplitude investigations were performed for each muscle individually, as well as for pooled data of muscles grouped by location. Characteristic pain intensity scores (CPIS; 0-100 points, von Korff) based on mean intensity ratings reported for current, worst and average pain over the last three months were used to allocate participants into LBP (≥30 points) or CTRL (≤10 points). Test-retest reproducibility between measurements was determined by a compilation of measures of reliability. Differences in muscular activities between LBP and CTRL were analysed descriptively for individual muscles; differences based on grouped muscles were statistically tested by using a multivariate analysis of variance (MANOVA, α =0.05).
Results: Thirteen individuals were included into the analysis of study 1. EMG latencies revealed reflex muscle activities following the perturbation (mean: 89 ms). Respective EMG amplitudes were on average 5-fold of those assessed in unperturbed strides, though being characterized by a high inter-subject variability. Test-retest reliability of muscle latencies showed a high reproducibility, both for muscles at the trunk and legs. In contrast, reproducibility of amplitudes was only weak to moderate for individual muscles, but increased when being assessed as a location specific outcome summary of grouped muscles. Seventy-six individuals were eligible for data analysis in study 2. Group allocation according to CPIS resulted in n=25 for LBP and n=29 for CTRL. Descriptive analysis of activity onsets revealed longer delays for all muscles within LBP compared to CTRL (trunk muscles: mean 10 ms; leg muscles: mean 3 ms). Onset latencies of grouped muscles revealed statistically significant differences between LBP and CTRL for right (p=0.009) and left (p=0.007) abdominal muscle groups. EMG amplitude analysis showed a high variability in activation levels between individuals, independent of group assignment or location. Statistical testing of grouped muscles indicated no significant difference in amplitudes between LBP and CTRL.
Discussion: The present research project could show that perturbed treadmill walking is suitable to provoke comprehensive reflex responses at the trunk and lower extremities, both in terms of sudden onsets and amplitudes of reflex activity. Moreover, it could demonstrate that sudden loadings under dynamic conditions provoke an altered reflex timing of muscles surrounding the trunk in people with LBP compared to CTRL. In line with previous investigations, compensation strategies seemed to be deployed in a task specific manner, with differences between LBP and CTRL being evident predominately at ventral sides. No muscular alterations exceeding the trunk could be found when being assessed under the automated task of locomotion. While rehabilitation programs tailored towards LBP are still under debate, it is tempting to urge the implementation of dynamic sudden loading incidents of the trunk to enhance motor control and thereby to improve spinal protection. Moreover, in respect to the consistently observed task specificity of muscular compensation strategies, such a rehabilitation program should be rich in variety.
During the last decade, high intensity interval training (HIIT) has been used as an alternative to endurance (END) exercise, since it requires less time to produce similar physiological adaptations. Previous literature has focused on HIIT changes in aerobic metabolism and cardiorespiratory fitness, however, there are currently no studies focusing on its neuromuscular adaptations.
Therefore, this thesis aimed to compare the neuromuscular adaptations of both HIIT and END after a two-week training intervention, by using a novel technology called high-density surface electromyography (HDEMG) motor unit decomposition. This project consisted in two experiments, where healthy young men were recruited (aged between 18 to 35 years). In experiment one, the reliability of HDEMG motor unit variables (mean discharge rate, peak-to-peak amplitude, conduction velocity and discharge rate variability) was tested (Study 1), a new method to track the same motor units longitudinally was proposed (Study 2), and the level of low (<5Hz) and high (>5Hz) frequency motor unit coherence between vastus medialis (VM) and lateralis (VL) knee extensor muscles was measured (Study 4). In experiment two, a two-week HIIT and END intervention was conducted where cardiorespiratory fitness parameters (e.g. peak oxygen uptake) and motor unit variables from the VM and VL muscles were assessed pre and post intervention (Study 3).
The results showed that HDEMG is reliable to monitor changes in motor unit activity and also allows the tracking of the same motor units across different testing sessions. As expected, both HIIT and END improved cardiorespiratory fitness parameters similarly. However, the neuromuscular adaptations of both types of training differed after the intervention, with HIIT showing a significant increase in knee extensor muscle strength that was accompanied by increased VM and VL motor unit discharge rates and HDEMG amplitude at the highest force levels [(50 and 70% of the maximum voluntary contraction force (MVC)], while END training induced a marked increase in time to task failure at lower force levels (30% MVC), without any influence on HDEMG amplitude and discharge rates. Additionally, the results showed that VM and VL muscles share most of their synaptic input since they present a large amount of low and high frequency motor unit coherence, which can explain the findings of the training intervention where both muscles showed similar changes in HDEMG amplitude and discharge rates.
Taken together, the findings of the current thesis show that despite similar improvements in cardiopulmonary fitness, HIIT and END induced opposite adjustments in motor unit behavior. These results suggest that HIIT and END show specific neuromuscular adaptations, possibly related to their differences in exercise load intensity and training volume.
Background:
Arising from the relevance of sensorimotor training in the therapy of nonspecific low back pain patients and from the value of individualized therapy, the present trial aims to test the feasibility and efficacy of individualized sensorimotor training interventions in patients suffering from nonspecific low back pain.
Methods and study design:
A multicentre, single-blind two-armed randomized controlled trial to evaluate the
effects of a 12-week (3 weeks supervised centre-based and 9 weeks home-based) individualized sensorimotor exercise program is performed. The control group stays inactive during this period. Outcomes are pain, and pain-associated function as well as motor function in adults with nonspecific low back pain. Each participant is scheduled to five measurement dates: baseline (M1), following centre-based training (M2), following home-based training (M3) and at two follow-up time points 6 months (M4) and 12 months (M5) after M1. All investigations and the assessment of the primary and secondary outcomes are performed in a standardized order: questionnaires – clinical examination – biomechanics (motor function). Subsequent statistical procedures are executed after the examination of underlying assumptions for parametric or rather non-parametric testing.
Discussion:
The results and practical relevance of the study will be of clinical and practical relevance not only for researchers and policy makers but also for the general population suffering from nonspecific low back pain.
Trial registration:
Identification number DRKS00010129. German Clinical Trial registered on 3 March 2016.
Background: The goal of this study was to estimate the prevalence of and risk factors for diagnosed depression in heart failure (HF) patients in German primary care practices.
Methods: This study was a retrospective database analysis in Germany utilizing the Disease Analyzer (R) Database (IMS Health, Germany). The study population included 132,994 patients between 40 and 90 years of age from 1,072 primary care practices. The observation period was between 2004 and 2013. Follow-up lasted up to five years and ended in April 2015. A total of 66,497 HF patients were selected after applying exclusion criteria. The same number of 66,497 controls were chosen and were matched (1:1) to HF patients on the basis of age, sex, health insurance, depression diagnosis in the past, and follow-up duration after index date.
Results: HF was a strong risk factor for diagnosed depression (p < 0.0001). A total of 10.5% of HF patients and 6.3% of matched controls developed depression after one year of follow-up (p < 0.001). Depression was documented in 28.9% of the HF group and 18.2% of the control group after the five-year follow-up (p < 0.001). Cancer, dementia, osteoporosis, stroke, and osteoarthritis were associated with a higher risk of developing depression. Male gender and private health insurance were associated with lower risk of depression.
Conclusions: The risk of diagnosed depression is significantly increased in patients with HF compared to patients without HF in primary care practices in Germany.
Prevalence of Achilles tendinopathy increases with age, leading to a weaker tendon with predisposition to rupture. Previous studies, investigating Achilles tendon (AT) properties, are restricted to standardized isometric conditions. Knowledge regarding the influence of age and pa-thology on AT response under functional tasks remains limited. Therefore, the aim of the thesis was to investigate the influence of age and pathology on AT properties during a single-leg vertical jump.
Healthy children, asymptomatic adults and patients with Achilles tendinopathy participated. Ultrasonography was used to assess AT-length, AT-cross-sectional area and AT-elongation. The reliability of the methodology used was evaluated both Intra- and inter-rater at rest and at maximal isometric plantar-flexion contraction and was further implemented to investigate tendon properties during functional task. During the functional task a single-leg vertical jump on a force plate was performed while simultaneously AT elongation and vertical ground reaction forces were recorded. AT compliance [mm/N] (elongation/force) and AT strain [%] (elongation/length) were calculated. Differences between groups were evaluated with respect to age (children vs. adults) and pathology (asymptomatic adults vs. patients).
Good to excellent reliability with low levels of variability was achieved in the assessment of AT properties. During the jumps AT elongation was found to be statistical significant higher in children. However, no statistical significant difference was found for force among the groups. AT compliance and strain were found to be statistical significant higher only in children. No significant differences were found between asymptomatic adults and patients with tendinopathy.
The methodology used to assess AT properties is reliable, allowing its implementation into further investigations. Higher AT-compliance in children might be considered as a protective factor against load-related injuries. During functional task, when higher forces are acting on the AT, tendinopathy does not result in a weaker tendon.
Since 1998, elite athletes’ sport injuries have been monitored in single sport event, which leads to the development of first comprehensive injury surveillance system in multi-sport Olympic Games in 2008. However, injury and illness occurred in training phases have not been systematically studied due to its multi-facets, potentially interactive risk related factors. The present thesis aim to address issues of feasibility of establishing a validated measure for injury/illness, training environment and psychosocial risk factors by creating the evaluation tool namely risk of injury questionnaire (Risk-IQ) for elite athletes, which based on IOC consensus statement 2009 recommended content of preparticipation evaluation(PPE) and periodic health exam (PHE).
A total of 335 top level athletes and a total of 88 medical care providers from Germany and Taiwan participated in tow “cross-sectional plus longitudinal” Risk-IQ and MCPQ surveys respectively. Four categories of injury/illness related risk factors questions were asked in Risk-IQ for athletes while injury risk and psychological related questions were asked in MCPQ for MCP cohorts. Answers were quantified scales wise/subscales wise before analyzed with other factors/scales. In addition, adapted variables such as sport format were introduced for difference task of analysis.
Validated with 2-wyas translation and test-retest reliabilities, the Risk-IQ was proved to be in good standard which were further confirmed by analyzed results from official surveys in both Germany and Taiwan. The result of Risk-IQ revealed that elite athletes’ accumulated total injuries, in general, were multi-factor dependent; influencing factors including but not limited to background experiences, medical history, PHE and PPE medical resources as well as stress from life events. Injuries of different body parts were sport format and location specific. Additionally, medical support of PPE and PHE indicated significant difference between German and Taiwan.
The result of the present thesis confirmed that it is feasible to construct a comprehensive evalua-tion instrument for heterogeneous elite athletes cohorts’ risk factor analysis for injury/illness oc-curred during their non-competition periods. In average and with many moderators involved, Ger-man elite athletes have superior medical care support yet suffered more severe injuries than Tai-wanese counterparts. Opinions of injury related psychological issues reflected differently on vari-ous MCP groups irrespective of different nationalities. In general, influencing factors and interac-tions existed among relevant factors in both studies which implied further investigation with multiple regression analysis is needed for better understanding.
Changing the perspective sometimes offers completely new insights to an already well-known phenomenon. Exercising behavior, defined as planned, structured and repeated bodily movements with the intention to maintain or increase the physical fitness (Caspersen, Powell, & Christenson, 1985), can be thought of as such a well-known phenomenon that has been in the scientific focus for many decades (Dishman & O’Connor, 2005). Within these decades a perspective that assumes rational and controlled evaluations as the basis for decision making, was predominantly used to understand why some people engage in physical activity and others do not (Ekkekakis & Zenko, 2015).
Dual-process theories (Ekkekakis & Zenko, 2015; Payne & Gawronski, 2010) provide another perspective, that is not exclusively influenced by rational reasoning. These theories differentiate two different processes that guide behavior “depending on whether they operate automatically or in a controlled fashion“ (Gawronski & Creighton, 2012, p. 282). Following this line of thought, exercise behavior is not solely influenced by thoughtful deliberations (e.g. concluding that exercising is healthy) but also by spontaneous affective reactions (e.g. disliking being sweaty while exercising). The theoretical frameworks of dual-process models are not new in psychology (Chaiken & Trope, 1999) and have already been used for the explanation of numerous behaviors (e.g. Hofmann, Friese, & Wiers, 2008; Huijding, de Jong, Wiers, & Verkooijen, 2005). However, they have only rarely been used for the explanation of exercise behavior (e.g. Bluemke, Brand, Schweizer, & Kahlert, 2010; Conroy, Hyde, Doerksen, & Ribeiro, 2010; Hyde, Doerksen, Ribeiro, & Conroy, 2010). The assumption of two dissimilar behavior influencing processes, differs fundamentally from previous theories and thus from the research that has been conducted in the last decades in exercise psychology. Research mainly concentrated on predictors of the controlled processes and addressed the identified predictors in exercise interventions (Ekkekakis & Zenko, 2015; Hagger, Chatzisarantis, & Biddle, 2002).
Predictors arising from the described automatic processes, for example automatic evaluations for exercising (AEE), have been neglected in exercise psychology for many years. Until now, only a few researchers investigated the influence of these AEE for exercising behavior (Bluemke et al., 2010; Brand & Schweizer, 2015; Markland, Hall, Duncan, & Simatovic, 2015). Marginally more researchers focused on the impact of AEE for physical activity behavior (Calitri, Lowe, Eves, & Bennett, 2009; Conroy et al., 2010; Hyde et al., 2010; Hyde, Elavsky, Doerksen, & Conroy, 2012). The extant studies mainly focused on the quality of AEE and the associated quantity of exercise (exercise much or little; Bluemke et al., 2010; Calitri et al., 2009; Conroy et al., 2010; Hyde et al., 2012). In sum, there is still a dramatic lack of empirical knowledge, when applying dual-process theories to exercising behavior, even though these theories have proven to be successful in explaining behavior in many other health-relevant domains like eating, drinking or smoking behavior (e.g. Hofmann et al., 2008).
The main goal of the present dissertation was to collect empirical evidence for the influence of AEE on exercise behavior and to expand the so far exclusively correlational studies by experimentally controlled studies. By doing so, the ongoing debate on a paradigm shift from controlled and deliberative influences of exercise behavior towards approaches that consider automatic and affective influences (Ekkekakis & Zenko, 2015) should be encouraged. All three conducted publications are embedded in dual-process theorizing (Gawronski & Bodenhausen, 2006, 2014; Strack & Deutsch, 2004). These theories offer a theoretical framework that could integrate the established controlled variables of exercise behavior explanation and additionally consider automatic factors for exercise behavior like AEE.
Taken together, the empirical findings collected suggest that AEE play an important and diverse role for exercise behavior. They represent exercise setting preferences, are a cause for short-term exercise decisions and are decisive for long-term exercise adherence. Adding to the few already present studies in this field, the influence of (positive) AEE for exercise behavior was confirmed in all three presented publications. Even though the available set of studies needs to be extended in prospectively studies, first steps towards a more complete picture have been taken. Closing with the beginning of the synopsis: I think that time is right for a change of perspectives! This means a careful extension of the present theories with controlled evaluations explaining exercise behavior. Dual-process theories including controlled and automatic evaluations could provide such a basis for future research endeavors in exercise psychology.