[Evaluation of the German new back school: muscular physiological characteristics]. / Evaluation der Neuen Rückenschule : Muskulär-physiologische Merkmale.

BACKGROUND: According to the biopsychosocial approach of the German new back school the core objectives are sustainable improvement of physical and psychosocial health resources. Subjects with non-specific low back pain were investigated to evaluate the desired physical effects. METHODS: Coordinative and postural motor exercises were evaluated by means of surface electromyography (EMG). Applying a modified waiting group design 56 participants were examined 3 months before the start, at the beginning and at the end of the new back school program as well as 3 and 12 months after completion and the results were compared to a healthy control group (n=56) matched for age and body mass index (BMI). RESULTS: Initially significant group differences were found in 18 % of all statistical calculations of the static and 6 % of the dynamic test situations. Considering the trunk muscles the most frequent significant alterations from normative data were found in the lumbar multifidus muscle (static tests 29 % and dynamic tests 7 %). No relevant changes in the number of statistical results could be detected directly after completion of the new back school program. Nevertheless, at 12 months follow-up the number of significant differences to the normative data of the control group dropped by one third to 12 % of all calculations with static loads. CONCLUSION: The adjustment effects at 12 months follow-up indicate a delayed positive influence of the new back school program on muscular physiological parameters. Individuals with chronic non-specific back pain showed a long-term profit from participation in the new back school program due to the initiated orientation to a modified more active lifestyle.

[Evaluation of the German new back school: pain-related and psychological characteristics]. / Evaluation der Neuen Rückenschule : Schmerz- und psychologische Merkmale.

BACKGROUND: Results related to the outcome of the classical back schools are inconsistent. Accordingly, a reformulation of the program integrating psychological and social aspects was performed as a necessary step for the development of the new back school in Germany. The aim of this study was to assess the effectiveness and sustainability of the new back school in subjects with non-specific back pain in the prevention setting. MATERIAL AND METHODS: In a modified waiting design, individuals were investigated with respect to demographical, pain-related and psychological characteristics 3 months before the start, at the start and at the end of the back school and as well as 12 months after completion. In addition, predictors for a successful participation were analyzed. RESULTS: A total of 88 subjects with back pain initially participated in the study. In the short and long-term course, low to moderate effects were detected; however, during follow-up a reduction of pain showed high effects. Depression as assessed by the hospital anxiety and depression scale (HADS) and passive coping strategies assessed using the coping strategies questionnaire (CSQ) were identified as predictors for response to the intervention. CONCLUSION: On the basis of the sample studied, the new back school proved to be an effective treatment for short and long-term reduction of pain-related stress and associated psychological aspects. Maladaptive, passive coping strategies and higher depression scores were associated with a higher probability of success in terms of pain reduction and functional improvement.

[Gait analysis after minimally invasive total hip arthroplasty]. / Ganganalyse nach minimal-invasiver Hüftprothesenimplantation.

Upon implantation of a hip prosthesis by total hip arthroplasty (THA), clinical criteria are not always sufficient for an objective assessment of the functional outcome. Thus, functional improvement of gait behavior was comparatively validated by instrumented 3D gait analysis for a current, minimally invasive surgical approach (MIS; anterolateral approach) and a conventional, transgluteal approach (KONV). In selected cases, disturbed motion sequences were registered by measuring the muscle activity via high-resolution, monopolar surface electromyography (S-EMG) above the operation area. Despite continuous and significant improvement of practically all analyzed kinematic and kinetic gait parameters for both surgical approaches already after 5 weeks but in particular after 6 and 12 months, no significant differences were detected between the 2 procedures for any parameter or time point. The S-EMG demonstrated non-physiological muscle activation on the operated, but also on the non-operated side, even at 6 months after surgery. Advantages of the MIS approach thus seem primarily restricted to early, post-operative results, such as more rapid pain reduction and rehabilitation.

SEMG activation patterns of thigh muscles during upright standing in haemophilic patients.

Although electromyography (EMG) is a common method to evaluate muscle activity, studies utilizing EMG in haemophilic patients are rare. The haemophilic arthropathy, resulting in altered afferent information is expected to cause disturbed activation and inter-muscular coordination patterns in haemophilic subjects. The aim of this study was to determine differences of selected knee muscles between haemophilic patients and non-haemophilic subjects during upright standing. Surface EMG (SEMG) amplitudes of rectus femoris, vastus medialis (VM), vastus lateralis (VL) and biceps femoris (BF) muscles of both sides were measured in 27 haemophilic patients (H) and 26 control subjects (C) while standing on an even surface. Data from both sides were pooled in C, but data of H were subdivided further according to major (H-MA) and minor (H-MI) affected joints. To normalize the data, amplitude ratios (percentage of cumulated activity) were calculated as well. Regardless of whether H-MA or H-MI was compared with C, amplitudes of all extensor muscles reached significantly higher levels in H (P < 0.05). SEMG amplitude ratios also differed between H and C. Independent of subgroup, BF showed significantly reduced activation ratios (P < 0.01). Only the ratios of VM and VL of H-MA could replicate the observed amplitude differences to C (P < 0.05). These findings show that while standing, haemophiliacs maintain the necessary stability demands through increased extensor activities and modulated coordination patterns. Although all thigh muscles of haemophiliacs are characterized by distinct atrophy, increased amplitude levels could be proved for the knee extensor muscles only. Therefore, general atrophy-related effects cannot explain these results.

Healthy humans use sex-specific co-ordination patterns of trunk muscles during gait.

Human gait patterns differ considerably between the sexes. Therefore sex specific trunk muscle activation patterns can be expected. Healthy volunteers of both sexes (51 women, 55 men) walked on a treadmill at speeds from 2 to 6 km/h. Surface electormyography was recorded from five pairs of trunk muscles. Grand averaged root mean square (rms) curves and amplitude normalised curves were calculated. Mean amplitudes and relative amplitudes were calculated as well. Mean amplitudes as well as relative amplitude levels were not generally sex specific, but differed for single muscles. Grand averaged rms curves of all investigated muscles differed between sexes. At low walking speeds, differences mostly originated from mean amplitude level differences, alternating between sexes. At higher walking speeds, amplitude curves became more phasic, differences again alternated between sexes. Therefore, trunk muscle co-ordination during gait is sex-specific. Any interpretation of trunk muscle co-ordination patterns during gait requires sex specific normatives.

[Quantitation of glutamate in the brain by using MR proton spectroscopy at 1.5 T and 3 T]. / Quantitative Bestimmung von Glutamat im Hirn mithilfe der MR-Protonenspektroskopie bei 1,5 T und 3 T.

PURPOSE: The influence of different magnetic field strengths on the quantification of glutamate was experimentally investigated by means of IN VITRO and IN VIVO (1)H-MR spectroscopic measurements at 1.5 T and 3 T. MATERIALS AND METHODS: In vitro (1)H-MR measurements of aqueous solutions of NAA, glutamate, glutamine and GABA were performed on two clinical MR scanners at 1.5 T and 3 T using a single voxel PRESS sequence (TR/TE = 10 000 / 30 ms). IN VITRO brain measurements were also performed at both field strengths using a PRESS 2D- (1)H-CSI-sequence (TR/TE = 5000 / 30 ms) in 6 volunteers. Spectra at 1.5 T and 3 T were compared with respect to the overlap of the single compound spectra and the deviations between estimated and nominally adjusted concentrations. In vivo spectra at both field strengths were compared with respect to SNR (Glu), line width and Cramer-Rao values of the estimated glutamate intensities by using the LCModel. For the thalamus, insular and parietal cortex mean Glu/tCr ratios were estimated and compared between 1.5 T and 3 T as well as with corresponding values in the literature. RESULTS: In general, an improved separation of signal maxima was observed in the IN VITRO spectra at 3 T. Except for GABA, all IN VITRO concentrations estimated at 3 T revealed lower deviations from their adjusted nominal concentration compared to 1.5 T: NAA (1.5 T: -5.5 %, 3 T: 0.7 %), glutamate (1.5 T: -18.1 %, 3 T: 12.3 %), glutamine (1.5 T: 44.8 %, 3 T: 9.2 %), GABA (1.5 T: - 24.8 %, 3 T: 33.8 %). The SNR of IN VIVO spectra at 3 T was nearly doubled compared to 1.5 T. The mean number of voxels with %SD (Glu)< 20 was distinctly lower at 1.5 T (53 %) than at 3 T (80 %). Estimated Glu/tCr ratios for thalamus, insular and parietal cortex lay in the upper range of the literature values. CONCLUSION: The results indicate that the advantageous distribution of signal maxima at 3 T allows an improved separation of the individual spectra. Both the higher initial magnetization at 3 T and the improved sensitivity of the phased array matrix coil used in the 3 T study result in an increased SNR, which leads to better reliability of the individual detection as well as a more accurate quantification of glutamate.

Sleep spindle evolution from infancy to adolescence.

OBJECTIVE: To investigate the development of frontally recorded sleep spindles from infancy to adolescence to provide normative data for pediatric sleep medicine. METHODS: Sleep spindle activity was investigated in 120 healthy subjects aged 3 months to 16 years in 12 age groups. At 2 a.m. (min 1:17 a.m., max 3:18 a.m.) 10 min of NREM 2 was checked. Spindles were visually scored in the electroencephalogram from F4/A1. RESULTS: The age dependency of interspindle interval, length of spindle, and spindle density, was statistically significant (Kruskal-Wallis p<0.0001). There were U-shaped curves for spindle length, spindle density, and an inverted U-shaped curve for the interspindle interval. Results of the post hoc U-test p<0.05 (Bonferroni corrected, m=66): Spindle length was minimal at 1.7 up to 3.0 years. Spindle density (number of spindles) was minimal between the ages of 1.7 and 2.3 years, thereafter there was a high increase that reached a plateau at age 5 years and remained up to 16 years. Interspindle interval was maximal at 1.7 and 2.3 years. CONCLUSIONS: Sleep spindle activity changes with maturation in terms of length and density. SIGNIFICANCE: The establishment of age-related normative data of sleep spindle activity can improve identification of NREM 2 in infancy, childhood, and adolescence, and enable detection of delayed neural maturation and/or sleep instability.

Back muscle activation pattern and spectrum in defined load situations.

For the prevention and rehabilitation of low back pain the understanding muscle function in the low back region is essential. Important aspects of function include the muscle activation patterns and muscle fatigue. In the low back region m. erector spinae plays a critical role. The different parts of this muscle complex differ considerably in function. Following the concept of Bergmark [A. Bergmark, Stability of the lumbar spine, Acta Orthop. Scand. 60 (1989) 1-54] trunk muscles can be divided in two subsystems, the global-mobilizing-system and the local-stabilizing-system. At present the multifidus muscles are assigned to the local whereas the longissimus and iliocostalis muscles are assigned to the global system. From results of the four parts of our investigation, it can be shown that essential information about muscle function can be obtained by spectral and intra- as well as inter-muscular surface EMG parameters. Obtained data demonstrated functional transitions between the local and global system of trunk muscles for the multifidus muscle.

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.

Simultaneous surface electromyography (SEMG) and 31P-MR spectroscopy measurements of the lumbar back muscle during isometric exercise.

The aim of this study was to demonstrate the feasibility of simultaneous surface electromyography (SEMG) and 31P-MR spectroscopy (31P-MRS) measurements on the back muscle of volunteers during the performance of an isometric exercise. Six volunteers (three male, three female) performed a modified Biering-Sörensen test inside a 1.5 T MR scanner while simultaneously recording SEMG signals. A surface coil was used for 31P-MRS with a CSI sequence. Spectra were collected with a voxel resolution of 40 mm x 40 mm x 100 mm and a temporal resolution of 30 s during periods of rest, sustained muscle contraction and recovery. The duration of muscle contraction was 150 s. SEMG analysis yielded a decrease of the mean SEMG frequency of approximately 20%. The SEMG amplitudes were constant or increased up to approximately 150% during exercise. 31P-MRS showed a maximum decrease of the phosphocreatine (PCr) amplitude down to approximately 32% of its initial value. Simultaneously, a doubling of the inorganic phosphate (Pi) signal was observed. The present study demonstrates that simultaneous SEMG and 31P-MRS measurements of the back muscle are feasible during isometric exercises.

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.

Surface EMG of the lumbar part of the erector trunci muscle in patients with fibromyalgia.

OBJECTIVE: To determine differences supposed in EMG parameters of the erector trunci region between patients with fibromyalgia and healthy subjects during defined investigation situations. METHODS: During sitting and standing in upright position surface EMG (SEMG) from 15 subjects with fibromyalgia and 10 healthy controls was performed using a 16-channel technique where the electrodes were applied in a well-defined grid pattern (gain 5000, 3 db points at 5 Hz and 700 Hz respectively). SEMG quantification was done by Fourier algorithm using 512 measurement points for calculation. RESULTS: An increased EMG amplitude could be recorded during rest in fibromyalgia patients compared with controls. Spatial amplitude differences (frequency range 100-500 Hz) in the low back region were significantly (p < 0.01) decreased in the patients' group during sitting. CONCLUSION: It is the first time that a decreased difference in EMG amplitude of different parts within a certain muscle could be proven in patients with fibromyalgia. As far as is known from the literature this result seems to be a uniquefinding in fibromyalgia patients.

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.

Biocybernetic investigations of pursuit and posture motor control--a strategy for a detailed characterization of movement disorders in brain-damaged children.

By means of a biocybernetic approach the pursuit and posture motor control of brain-damaged children with spastic hemiparesis and disturbed motor coordination of mild extent were investigated. The postural motor control system was loaded by pseudostochastic binary torque sequences applied to the wrist. The dynamics of this system were characterized on the basis of the parameters forearm displacement as well as surface-EMG of M. Biceps and Triceps (calculations of weight functions). The pursuit motor control was analyzed by a pursuit tracking method. By this way the motor capacity for fine and rough motor coordination, motor rhythm, motor adaptation, the maximal speed of movements and motor reaction time could be tested. Considering these results a characterization of movement control on different levels of motor regulation was possible (dynamics of muscular, spinal, and supraspinal components of motor control).

[Model studies of muscle postural control in children with spastic hemiparesis: pathophysiologic and clinical relevance]. / Modelluntersuchungen der Muskelhalteregelung bei Kindern mit spastischer Hemiparese: pathophysiologische und klinische Relevanz.

By means of a biocybernetic method the transfer behaviour of postural motor control system was characterized in children with spastic hemiparesis and matched healthy subjects. There were significant differences between the initial reactions of the postural motor systems of both examination groups to pseudorandom torque sequences (fig. 3, tab. 1). Considering these results we created a postural motor control model for both examinations groups (model see fig. 2). From this model it is possible to estimate separately the biomechanical effect of augmented segmental reflex activity and muscle-inherent dysfunctions in patients with spastic syndrome (fig. 4). The determination of these disturbed functions enables us to give instructions on a focused treatment of spastic syndrome according to the dominant dysfunction quantified.

Electrophysiological characterization of central sensory and motor pathway function in patients with moderate hemiparesis. II. Clinical results.

The central sensory and motor pathway function in patients with moderate hemiparesis and in healthy persons was selectively characterized by evaluation of latencies of short (R1) and long (R2) latency EMG responses as well as simultaneously recorded sensorimotor potentials (N19, N26) evoked by electrical stimulation of median and peroneal nerve (additionally, calculation of peripheral and central sensory/motor conduction times). This investigation procedure permits a noninvasive quantification of disturbed central sensory and motor pathway function in hemiparetic patients. The results found are in agreement to clinical, CT and other examination findings.

Electrophysiological characterization of central sensory and motor pathway function in patients with moderate hemiparesis. I. Methodical approach.

The central sensory and motor pathway function in healthy persons and patients with several neurological disorders was selectively characterized by evaluation of latencies of short (R1) and long (R2) latency EMG responses as well as simultaneously recorded somatosensory potentials (N19, N26) evoked by electrical stimulation of N.medianus and N.peroneus. On the basis of these latencies the peripheral and central sensory/motor conduction times were calculated. By using this investigation procedure a selective quantification of central pathway functions is possible.

[Psychophysiological studies in the framework of objective diagnosis of neuroses with factor and discrimination analyses]. / Psychophysiologische Untersuchungen im Rahmen objektiver Neurosendiagnostik mit Faktoren- und Diskriminanzanalysen

This paper describes a complex method of collecting objective data to be used in the diagnosis of neuroses on the basis of clinical, experimental psychological, and objective psychophysiological parameters. The data collected was processsed using the methods of factor and discriminatory analysis. The results obtained clearly show that this approach to additional objective diagnosis may be successfully used in spite of some procedural difficulties.

[Biocybernetic tests on the identification and mathematical modelling of the motor regulation system and its disorders]. / Biokybernetische Untersuchungen zur Identifikation und mathematischen Modellierung des motorischen Regel-systems und seiner Störungen.

By means of the biocybernetically conceived step and impulse loads on the forearm the motor postural regulation of healthy test persons and neurological patients with rigor, spasticity and flaccid pareses of slight degree, respectively, were examined. The analysis of the forms of the transient processes rendered possible a significant differentiation of the groups of test persons and patients. With the help of the mathematical mode the response curves of healthy test persons as well as of patients could be simulated with sufficient exactness. Apart from the step and impulse loads psendorandom binary series of test signals are particularly suitable for the analysis of the motor postural regulation.