[Poverty, public transfers and health: An analysis on self-rated health of social benefit recipients in Germany]. / Armut, öffentliche Sozialtransfers und Gesundheit: Eine Analyse zur subjektiven Gesundheit von Sozialleistungsbeziehern in Deutschland.

BACKGROUND: Prevention and reduction of poverty are key elements of social welfare policy in Germany. This study is the first analysis of self-rated health of individuals that escape poverty by benefiting form public transfers. METHODS: Analyses are based on the German Socio-economic Panel (GSOEP) of 2010. Self-rated health was based on subjective assessment of general health status. Subjects were directly asked about receipt of public transfers. Income poverty was based on the equalized disposable income and is applied to a threshold of 60% of the median-based average income. We analyzed the association between self-rated health and pre- and post-transfer poverty by means of descriptive analyses and binary logistic regression. RESULTS: After adjusting for age, we found a significantly higher risk of poor self-rated health among those who escaped income poverty due to the receipt of social transfers compared to others (ORWomen: 1.85; 95%-CI: 1.27-2.69; ORMen: 2.57; 95%-CI: 1.63-4.05), in particular to those at risk of post-transfer poverty. These poverty-related inequalities in health were predominantly explained by nationality, occupational status, household type and long-term care within the household. CONCLUSION: This study provides first evidence that the receipt of public transfers is associated with increased risk of poor health in the light of impending income-poverty. This study adds to the current debate about the social and health implications of public transfers in the relationship between poverty and health.

[Challenges in the Analysis of Health Care Inequalities in Pediatric Rehabilitation]. / Herausforderungen in der Analyse von Versorgungsungleichheiten in der Kinderrehabilitation.

BACKGROUND: Social inequalities on access and utilization of inpatient rehabilitation among adolescents have rarely been studied. METHODS: Parents of children with chronic health conditions (age of 7-17) were interviewed about access and utilization of inpatient rehabilitation. Parents were recruited through pediatricians as well as rehabilitation centers in Central Germany. RESULTS: Despite of numerous recruitment measures the participation by pediatricians was low. Also expanding the sample did not remedial. Furthermore, fewer adolescents with need of rehabilitation were achieved than expected. The analysis is subject to these restrictions, nevertheless, they still allow explorative statements about access and utilization of pediatric rehabilitation. CONCLUSION: Despite major challenges in recruitment, pediatricians should be considered into analysis of inequalities in rehabilitation because of their gatekeeper function.

Improved evaluation of back muscle SEMG characteristics by modelling.

Surface EMG (SEMG) as non-invasive method is a valuable tool in functional studies of movement co-ordination. The interpolation of the SEMG power (EMG mapping) gives information about intra- and inter-muscular co-ordination. It has been shown that SEMG maps of low back pain patients and healthy subjects differ. The only major drawback to SEMG is that volume conduction of muscle tissue, fat, and skin decreases the spatial and temporal resolution of signals. To improve the interpretation of SEMG signals, we have applied high pass filtering of cross covariance functions, which has proved to be useful in increasing the spatial resolution, to SEMG data of the back region. Experimental data demonstrate that SEMG signals from the back extensors show only rarely signs of action potential propagation. This behaviour, also described in the literature, can be explained by a model assuming short, deep muscle fibres, having bipolar end effects, with overlapping positions parallel to the fibre direction. This condition is fulfilled by the mm. multifidii et rotatores which are part of the m. erector spinae. Although the model is simplistic, the agreement between simulations and experiments is good.

Surface EMG-recordings using a miniaturised matrix electrode: a new technique for small animals.

A new method for multichannel surface-EMG measurements in small animals is presented. The underlying scientific aim is the characterisation of the spreading and the co-ordination of skeletal muscle activation between different muscles or muscle parts, depending on various motor tasks. The myoelectrical signals were recorded monopolarly by a 16-channel matrix electrode on the muscle surface directly under the skin on the fascia of the investigated muscle, without damaging the muscle. Surface-EMG's were recorded for at least 5 days after surgery without electrical interferences. During defined motor tasks, the projection of the myoelectrical activation of the different parts of the M. triceps brachii of rats (Rattus norvegicus), pikas (Ochotona rufescens) and cuis (Galea musteloides) or the M. anconeus of toads (Bufo marinus) on the muscle surface was mapped. The locomotion of the investigated animals was monitored by a three-dimensional kinematic analysis (video and/or high-speed cineradiography). There was no perceptible influence from application of EMG matrix electrode. The miniaturised matrix electrode seemed practicable in gaining insight into changes in myoelectrical activation patterns (EMG mapping). This allows a characterisation of the intramuscular co-ordination processes corresponding to the actual morphofunctional state of the investigated animals.

Surface EMG mapping of the human trapezius muscle: the topography of monopolar and bipolar surface EMG amplitude and spectrum parameters at varied forces and in fatigue.

OBJECTIVES: To investigate the factors affecting the topography of trapezius muscle EMG, multichannel recordings were made at different forces of isometric shoulder elevation and during fatiguing exercise. METHODS: Twenty-eight channels of monopolar EMG were recorded from an array of 4 x 7 electrodes placed on the upper trapezius muscle. From the monopolar EMG and the bipolar derivations the root mean square (RMS(monopolar), RMS(bipolar)) and power spectrum median frequency (MF(monopolar), MF(bipolar)) were calculated. RESULTS: The maximum RMS(monopolar) was located above the middle part of the trapezius muscle, where a minimum was found for RMS(bipolar). The cranial-caudal RMS distribution shifted upwards when the force was increased from 50 to 100% MVC and during fatigue. MF(bipolar) showed a peak above the endplate region, where the MF(monopolar) was low. During fatigue the normalized MF slope was independent of the cranial-caudal electrode position, but MF(monopolar) decreased most strongly at positions above the endplate region, where MF(bipolar) decreased less. CONCLUSIONS: While the changes in MF reflected metabolic properties and volume conduction phenomena in the muscle, changes in RMS reflected a compensation for the fatigue processes within the muscle. The RMS changes in fatigue can be explained by the direction of the fibres involved in shoulder elevation.

Selective spatial information from surface EMG after temporal filtering: the application to interference EMG using cross-covariance analysis.

OBJECTIVE: An increased spatial resolution in multichannel surface EMG recordings would provide new possibilities for the investigation of intermuscular and intramuscular coordination. A known analytical solution for volume conduction allows the conclusion that a high pass filtered surface electromyography (SEMG) signal contains information from a smaller environment near the recording electrode and therefore provides a higher spatial resolution. METHODS: The present paper concerns experiments on 9 subjects to measure, from the human biceps brachii muscle during static isometric contraction, using multichannel surface EMG. Cross-correlation functions between bipolar SEMG channels were calculated and high pass filtered. RESULTS: The correlation peaks showed the signs of propagating action potentials. The spatial width in the direction perpendicular to the muscle fibres decreased with increasing cut-off frequency. There exists an optimal cut-off frequency, which provides the best spatial resolution. It correlates with the thickness of the subcutaneous fat layer which causes a minimum depth of the active muscle fibres measured. CONCLUSIONS: High pass filtered cross-covariance functions of bipolar SEMG channels have an increased spatial resolution perpendicular to the muscle fibre direction and the frequency content of the signals can potentially give an indication of the depth of the active muscle fibres.

Characteristics of heart rate fluctuations and respiratory movements during orienting, passive avoidance and flight-fight behaviour in rabbits.

In the present study different heart rate patterns were demonstrated to accompany flight-fight behaviour, orienting behaviour and passive avoidance in rabbits. Flight-fight behaviour was characterized by markedly increased heart rate and diminished overall heart rate variability. The effect was mediated by vagal inhibition and beta-adrenergic activation in a type-specific relation. Orienting behaviour was accompanied by a smaller heart rate increase and the exaggeration of slow heart rate fluctuations. The latter effect was absent during beta-adrenergic blockade suggesting a behaviourally provoked beta-adrenergic activation. Single beta-adrenergic blockade did not change the characteristics of the heart rate fluctuations at rest. During passive avoidance a vagally mediated heart rate deceleration was followed by a slow heart rate return toward the initial heart rate level. This level was not reached during beta-adrenergic blockade. The enhanced overall heart rate variability during passive avoidance was mainly caused by strengthened respiratory-induced heart rate fluctuations and, furthermore, by exaggerated slow rhythmical heart rate fluctuations. The latter effect was not observed during beta-adrenergic blockade and is referred to as an orienting component within passive avoidance. Three individual behavioural types may be differentiated in rabbits 'Weisses Gross-Silber' by stable behavioural characteristics i.e. spontaneous motor activities, preferred postures at rest and coping behaviour. The results of the present study suggest that different neurovegetative reaction types, i.e. dominating beta-adrenergic or vagal activation are correlated with stable behavioural characteristics, especially in terms of preferring active or passive coping behaviour, respectively.

A topographical analysis of spectral electromyographic data of the human masseter muscle under different functional conditions in healthy subjects.

In 20 healthy subjects, 16-channel surface electromyograms (EMG) were recorded with the mandible in its postural position, during compensation for forces applied from ipsilateral, contralateral and frontal positions, and during force-constant biting on a unilaterally placed force transducer. After artefact elimination, EMG power spectra were calculated on the basis of the original EMG curves via fast Fourier transformation. Using spectral EMG characteristics, EMG maps were computed by means of an interpolation algorithm and an imaging procedure. Spectral EMG maps were demonstrated for all the test conditions. Significant differences of myoelectrical activity were verified between the 16 electrode positions. Moreover, the levels and/or the topographical distributions of spectral EMG powers differed significantly between the test conditions. During biting as well as with contralaterally and frontally applied forces, the highest EMG activity was found in the inferior third of the masseter and the lowest in the superior third. With ipsilaterally applied forces, the topographical distribution of the total EMG power was completely changed. The power maximum was frequently demonstrated in the superior, especially the posterosuperior, third of the muscle, the minimum in the inferior third. In the postural position of the mandible, EMG activity decreased from the anterior to the posterior regions of the masseter. If the bite force or the horizontally applied forces were enhanced, EMG activity increased significantly but the EMG map structures were only changed in some details. The topographical distribution of myoelectrical activity demonstrated by EMG maps characterizes the intramuscular activation patterns of distinct masseter functions.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative-topographic and temporal characterization of myoelectrical activation patterns: new diagnostic possibilities in neurology, physiotherapy and orthopaedics.

In controls and patients with different syndromes (spastic/flaccid paresis, low back pain syndrome), the myoelectrical activation patterns of complex muscles (M. biceps brachii, M. quadriceps femoris, M. masseter) or synergistic/antagonistic muscle groups in the back region during isometric muscle contractions and defined movements were determined by monopolar 16 (32) channel surface EMG recordings. On the basis of these recordings, maps of myoelectrical activation ("EMG-maps") were calculated. This method permits a detailed quantitative-topographic EMG analysis including the characterization of therapy effects.

[Neuroautonomic organization of cardiac rhythm and of nonrhythmic oscillations in the frequency of cardiac contractions and respiration]. / Neirovegetativnaia organizatsiia serdechnykh ritmov i neritmichnykh kolebanii chastoty serdechnykh sokrashchenii i dykhaniia.

In 25 chronic adult rabbits, the functional organization of neurally mediated short-term rhythms and patterns of the heart rate (HR) were investigated. The respiration-unrelated arrhythmia seems to be vagally mediated only, being abolished with atropine. The respiration-related arrhythmia exists not only within the range of respiratory frequency but also in lower frequencies as discovered by spectral and coherence analysis. During motor activity, there is a systematic correlation among increasing premotor, motor and amygdaloid multispike activities, increasing HR and depressed HR-rhythms with limbic initiation of motor and concomitant autonomic patterns, "Immobile confrontations" alone produces vagally induced HR-decrease and increased amplitudes of vagal HR-rhythms with a concomitant cortical multispike depression, a mirror image of the autonomic patterns after nociceptive stimulation.

A review of national health policies and professional guidelines on maternal obesity and weight gain in pregnancy.

Maternal obesity creates an additional demand for health-care services, as the routine obstetric care pathway requires alterations to ensure the most optimal care for obese women of childbearing age. This review examines the extent to which relevant national health documents reflect and respond to the health implications of maternal obesity and excessive gestational weight gain. A targeted search of peer-reviewed publications and grey literature was conducted for each country to identify national health documents, which were subsequently content analyzed according to an adapted framework. A total of 37 documents were identified, including one policy, 10 strategies and 26 guidelines, published within the last 10 years. Out of the 31 countries investigated, only 13 countries address maternal obesity while none address excessive gestational weight gain. We found inconsistencies and gaps in the recommendations to health-care service providers for the management of maternal obesity and weight gain in pregnancy. The findings show that only limited guidance on maternal obesity and gestational weight gain exists. The authors recommend that international, evidence-based guidelines on the management of maternal obesity and excessive gestational weight gain should be developed to reduce the associated health-care and economic costs.

Mutational analysis of subunit G (Vma10p) of the yeast vacuolar H+-ATPase.

The G subunit of V-ATPases is a soluble subunit that shows homology with the b subunit of F-ATPases and may be part of the "stator" stalk connecting the peripheral V(1) and membrane V(0) sectors. When the N-terminal half of the G subunit is modeled as an alpha helix, most of the conserved residues fall on one face of the helix (Hunt, I. E., and Bowman, B. J. (1997) J. Bioenerg. Biomembr. 29, 533-540). We probed the function of this region by site-directed mutagenesis of the yeast VMA10 gene. Stable G subunits were produced in the presence of Y46A and K55A mutations, but subunit E was destabilized, resulting in loss of the V-ATPase assembly. Mutations E14A and K50A allowed wild-type growth and assembly of V-ATPase complexes, but the complexes formed were unstable. Mutations R25A and R25L stabilized V-ATPase complexes relative to wild-type and partially inhibited disassembly of V(1) from V(0) in response to glucose deprivation even though the mutant enzymes were fully active. A 2-amino acid deletion in the middle of the predicted N-terminal helix (DeltaQ29D30) allowed assembly of a functional V-ATPase. The results indicate that, although the N-terminal half of the G subunit is essential for V-ATPase activity, either this region is not a rigid helix or the presence of a continuous, conserved face of the helix is not essential.

Personality and quantified neuromuscular activity of the masticatory system in patients with temporomandibular joint dysfunction.

Patients suffering from temporomandibular joint dysfunction syndrome (TMJS) and healthy volunteers were examined by means of MMPI questionnaire and electromyography (masseter, anterior temporal and anterior digastric muscles) at rest and during natural chewing. In response to mental load (arithmetic chain task) TMJS patients showed an increase in postural activity and partly rhythmical short augmentations above the mean level of this activity. Chewing potentials were considerably diminished in patients compared with controls. There was evidence for neurotic disorders in the patients MMPI (neurotic triad: higher scores on hypochondria, depression, hysteria). Significant differences (multivariate variance and discriminant analysis: P less than 0.001) between patients and controls were found both in the group with psychic signs (MMPI scales) and in the group of quantitative electromyographic parameters. However, a sufficient discrimination was only obtained by a combination of both parameter groups. The results show that probably psychic dynamics, as well as the structure of neuromuscular activity within the masticatory system, are important in the aetiopathogenesis of TMJS.

[Methodologic studies in dynamic EMG mapping based on the Hilbert transformation]. / Methodische Untersuchungen zum dynamischen EMG-Mapping auf der Basis der Hilbert-Transformation.

On the basis of Discrete Hilbert Transformation spectral parameters for dynamic EMG analysis can be introduced. Within analysis intervals which are used in the same manner as in spectral analysis, the momentary power of EMG frequency bands can be computed as time series of the same interval duration. A close connection exists between momentary power and the current phenomenology of power spectral analysis because the momentary power of a defined frequency band can be seen as the exact dynamic equivalent of the corresponding mean power value deduced from the power spectrum. A multichannel EMG recording (greater than or equal to 16 channels) makes the representation of the topographical distribution of the spectral parameter by a coloured map possible. Additionally, the momentary power can be used to calculate map sequences. In this way, changes of EMG activity can be quantified by map sequences of an arbitrary time resolution. By calculation of momentary frequency via DHT an artefact detection scheme for ECG interference can be suggested. A completion of this methodology can be carried out by applications of adaptive filtration procedures. Using this concept of EMG processing, a new and common methodical basis of EMG power spectral analysis can be introduced.

[Quantification of artefacts in surface EMG by validating the lower frequency limit in clinico-physiologic studies]. / Quantifizierung von Artefakten im Oberflächen-EMG zur Validisierung der unteren Grenzfrequenz bei klinisch-physiologischen Untersuchungen.

The surface-EMG becomes more and more important because computer assisted analysing systems can be applied. The occurrence of artefacts makes it very difficult to compare several recorded EMG channels with each other. In this study a frequency related quantification of movement artefacts and ECG-related influences on the EMG is carried out to select a suitable lower cut-off frequency for surface-EMG investigations. In 764 monopolar surface-EMG-recordings of the neck and back muscles the solely artefact-caused part of EMG-segments was analysed and quantified by means of modelling methods.

[Quantitative topographic characterization of the myoelectric activity distribution of the masseter muscle: mapping of spectral EMG parameters]. / Quantitative topographische Kennzeichnung myoelektrischer Aktivitätsverteilungen des M. masseter: Mapping spektraler EMG-Parameter.

A new method for quantitative characterization of myoelectrical masseter activity distribution by mapping of spectral EMG-parameters is described. The surface electromyograms of M. masseter were monopolarly recorded (16 channels). On the basis of registered EMG intervals (512 ms) the spectral EMG power of several frequency bands was calculated (Fast Fourier Transformation). The spectral EMG parameters between the 16 electrode positions were estimated by linear interpolation (4-nearest neighbours algorithm). Afterwards the spectral EMG parameters were fitted in a grey-tone or colour scale with 10 intervals. The so obtained EMG activity maps ("EMG-Maps") permit a quantitative-topographic characterization of myoelectrical masseter activity during different functional load procedures. The frequency range which is to consider in masseter surface-EMG investigations encloses frequencies between 15 and 500 Hz. The topography of EMG activation pattern of M. masseter is only described in a comprehensive manner when the electrode array consists of 16 electrodes and more. During defined motor tasks like clenching with controlled forces the reproducibility of EMG-Maps which respect to the topography of EMG activity pattern is very high. The absolute values of spectral EMG power as well as power changes of selected band ranges during clenching correlate to the extent of chewing forces.

[Mapping spectral EMG parameters of the masseter muscle in normal probands under defined loads]. / Mapping spektraler EMG-Parameter des M. masseter bei gesunden Probanden unter definierten Belastungen.

In 20 healthy volunteers 16-channel surface electromyograms were monopolarly recorded from the right and left masseter muscle during defined functional conditions (force-constant bite, right and left hand side, 196, 333, 530 N chewing force, during a compensation of a load directed from a frontal or a lateral position to the mandible (20, 49, 69 N), during rest position of the mandible). The EMG curves were quantified by the calculation of spectral EMG-parameters (FFT). With respect to the muscle a topographic oriented representation of the myoelectrical activity was realised by a mapping of spectral EMG-parameters. The monopolarly recorded EMG activities significantly differed between the 16 electrode positions (topographic EMG distribution pattern). During the several examination conditions of the masseter muscle different topographic distribution pattern of the myoelectrical activity were found. Moreover, the total EMG power between the muscle functions differed too. The level of the load influenced the spectral EMG power as well as, partly, the topographic EMG distribution pattern.

[Control of isometric muscle contraction in muscle hypotonia of central origin: EMG mapping analysis]. / Kontrolle der isometrischen Muskelkontraktion bei muskulärer Hypotonie zentralen Ursprungs: EMG-Mapping-Analyse.

Electromyographic and mechanographic investigations in patients with muscular hypotonia, which is, for instance, a side-effect after stereotactic treatment of tremor syndromes, permit the presumption that in this sensomotor open-loop situation the decreased muscular resistance to stretching during isometric contraction (initial stiffness) is caused by changes of muscular innervation pattern. Probably, the innervation pattern during tonic activity is changed by a shift of a more tonic motoneurone behaviour to motoneurone activities with predominantly phasic characteristics. In 17 controls and 4 patients with muscular hypotonia caused by stereotactic lesions of VIM area (treatment of tremor syndromes) the EMG of right and left side forearm flexors (especially the activity of the M. biceps brachii) was investigated by a sophisticated, topographically oriented 16-channel-surface-EMG-technique ("EMG-Mapping") during slight isometric contraction. EMG-Maps of forearm flexors (especially of M. biceps brachii) in patients with centrally evoked muscular hypotonia demonstrate that in these open-loop conditions the motor control is changed. For this the reason could be a shift of the activated motor units from a predominantly static to a more phasic functional behaviour. The latest results on muscular activation processes in cats support this presumption.

Surface EMG of shoulder and back muscles and posture analysis in secretaries typing at visual display units.

OBJECTIVE: A study was carried out to investigate temporal changes of activation of shoulder and back muscles in workers at visual display units by means of surface EMG. Moreover, postural parameters were recorded to distinguish fatigue-related from posture-related changes of the myoelectrical activity. METHODS: Nine healthy female office workers typed texts spoken from tape during three 1-h-long sessions. After the first and again after the second hour there was a break of 15 min. Sixteen-channel surface EMG was bipolarly recorded from the erector spinae, trapezius, deltoid and sternocleidomastoid muscles. Root mean square (RMS) and power spectrum median frequency of the EMG were calculated. Sitting posture was assessed using an eight-channel movement analysis system with ultrasound markers. The position of the seventh cervical spinous process and the left and the right acromion were analysed synchronously with the EMG characteristics using regression analysis. RESULTS: The normalised RMS of the left and right trapezius muscle increased, while the median frequency did not change. The increase of the normalised RMS was significantly lower when the linear influence of posture was excluded. On average, the distance between C7 and the left and right acromion decreased within each working an hour. C7 became lower on average by 5.5 mm within an hour, whereas the acromions became lower by only 1.7 mm (left) and 3.3 mm (right). CONCLUSION: The increase in trapezius muscle activity was partly related to a lifting of the shoulders to compensate a slight slumping of the back. Another part of the EMG activity increase has to be attributed to fatigue, to attention-related activity or to the combination of both. Therefore, training of the back muscles and a varied organisation of work might have a preventive effect with respect to musculoskeletal complaints in VDU workers.