[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.

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.

[5-year follow-up study of total knee arthroplasty by means of EMG mapping]. / Nachuntersuchungsergebnisse mittels EMG-Mapping - 5 Jahre nach Knieendoprothesenimplantation.

AIM: The objective of the present study was to evaluate the long-term functional results after implantation of a total knee arthroplasty (TKA) objectively and quantitatively. METHOD: Functional parameters (muscular coordination, strength and range of motion) and the subjective satisfaction of the patients were measured by means of EMG mapping, isokinetics, ultrasound and a questionnaire in 21 patients with TKA 5.1 years after implantation of the TKA. RESULTS: 81 % of the investigated patients were subjectively satisfied. The isokinetic results showed a significant improvement of the extensor strength and of the relation between flexors and extensors. Patients who had been more physically active over these 5 years reached significantly better results. The results of EMG mapping showed good overall retention of the satisfactory coordination levels resulting from the initial in-patient rehabilitation. But the coordination patterns demonstrated clear changes showing highly activated areas in the region of the M. vastus medialis. The range of motion and the contraction capacity showed no further improvement compared with the results 26 weeks after implantation of the TKA. CONCLUSION: Long-term results after implantation of a TKA showed a good muscular coordination, strength and range of motion. A higher physical activity level led to better functional results and greater overall satisfaction of TKA patients 5 years after implantation.

[Objective assessment of results of special hydrotherapy in inpatient rehabilitation following knee prosthesis implantation]. / Objektivierung der Ergebnisse einer speziellen Wassertherapie in der stationären Rehabilitation nach Knieendoprothesenimplantation.

AIM: Based on our own previous surface EMG investigations (EMG mapping), it has been shown that disturbances in coordination, proprioception and strength measured before and after implantation of a total knee arthroplasty (TKA) can be treated successfully with standard physical therapy during in-patient rehabilitation. The objective of the present study was to evaluate the therapeutic effect of a special type of hydrotherapy. METHOD: 25 patients with TKA were treated for 3 weeks with a standardized hydrotherapy training during in-patient rehabilitation. Several diagnostic methods (EMG mapping, Isokinetics, Ultrasound) were applied to objectify and quantify changes in muscular coordination and strength at 4, 7, and 26 weeks postoperative. These results were compared with the results of 38 TKA patients treated with a "standard rehabilitation program" and with the results of 20 healthy persons. RESULTS: EMG mapping as well as isokinetics and ultrasound permitted an objective characterization of the results. Patients treated with the special hydrotherapy showed greater improvements in the investigated items of coordination and strength than patients treated with the "standard rehabilitation program". For example, in the hydrotherapy group a significantly better contraction capacity of the M. vastus intermedius was measured. The intensive hydrotherapy was tolerated by all patients and reached good acceptance. CONCLUSION: The investigated hydrotherapy technique leads to better muscular coordination and strength, which can provoke a better stabilization of the knee joint. Therefore, the early and intensive application of hydrotherapy for improving coordination and strength in the rehabilitation of patients with total knee arthroplasty is advisable.

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.

Spatiotemporal surface EMG characteristics from rat triceps brachii muscle during treadmill locomotion indicate selective recruitment of functionally distinct muscle regions.

Multichannel surface EMG recordings of a multiheaded skeletal muscle during cyclic locomotion combined with cineradiography were analysed in a chronic experiment. The resulting detailed two-dimensional activation pattern from the long and lateral triceps brachii heads of the rat during treadmill locomotion were combined with gait characteristics and fibre typing of the muscle. Shortly before ground contact of the forelimb, maximum muscle activity was found in the proximal part of the long head of the muscle. During the stance phase maximum activity was observed in the proximal part of the lateral head. The frequency dependent behaviour of cross-covariance functions over both muscle heads confirmed this selective shift in activation. In the lateral triceps brachii head of the investigated rats, exclusively type II fibres were found. In the long head the frequency of type I fibres was the highest in the deep muscle layers, proximally more than distally, whereas type II fibres were dominant in more superficial muscle layers. A combination of physiological and histological findings supports an anticipating mechanism whereby fine-tuning of the vertical foot down manoeuvre is mainly achieved by the (type I fibre dominated) proximal deep compartment of the biarticular long triceps brachii head and force generation is predominantly executed by the monoarticular lateral triceps brachii head.

[EMG mapping--applications and results in assessment of muscle coordination disorders in patients with a knee endoprosthesis (knee TEP)]. / EMG-Mapping--Anwendung und Ergebnisse zur Erfassung muskulärer Koordinationsstörungen bei Patienten mit Knieendoprothese (Knie-TEP).

QUESTION: Disorders of coordination, strength and proprioception are frequently described after surgery of the knee joint. These muscular coordination disorders have not yet been studied sufficiently. The purpose of this study was the objective-quantitative characterization of muscular coordination disorders of the M. quadriceps femoris by means of EMG mapping in the arthrotic knee joint and their progress after the implantation of a total knee arthroplasty and after in-patient rehabilitation. METHODS: The extent and pattern of activation (EMG mapping) of the M. quadriceps femoris were investigated by means of a 16-channel EMG technique in 38 patients before and after the implantation of a total knee arthroplasty (type LCS). RESULTS: EMG mapping permitted an objective-quantitative characterization of the extent and pattern of activation in the M. quadriceps femoris before and after the implantation of a total knee arthroplasty and therefore the objectivation of muscular coordination disorders. Muscular coordination disorders were present already before surgery and were also caused by the implantation of a total knee arthroplasty. These coordination disorders can be improved by an inpatient rehabilitation. CONCLUSIONS: The development of exercise programs adequate for everyday life is necessary to remove quickly and actually the demonstrated coordination disorders.

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.

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.

Force regulation is deficient in patients with parietal lesions: a system-analytic approach.

By means of a quantitative system-analytic investigation strategy, the postural motor control of the fingers was evaluated, to characterise the possible deficit of force regulation in patients with parietal lesions. In spite of a normal response to short torque pulses, the parietal-lesion patients had difficulties in returning to the preload level after the application of an additional step torque load to fingers II-IV of their left or right hands. The control offset (measured 500 ms after step torque application) was significantly larger in the patient group. This deficit in the investigated patients with parietal lesions to compensate for step torque loads was not due to a paresis, but rather resulted from a disturbance in the generation of a sufficient counterforce against the applied step torque within an adequate time window and motor pattern. This distinct force-regulation deficit was found in patients with left- and right-sided parietal lesions.

[EMG surface polygraphy of the pelvic floor--description of functional changes after radical prostatectomy]. / EMG-Oberflächenpolygraphie des Beckenbodens--Beschreibung von funktionellen Veränderungen nach radikaler Prostatektomie.

Urinary stress incontinence after radical prostatectomy could be cured by physiotherapy in a high percentage. The authors developed an investigation procedure for description of myoelectrical activity of pelvic floor with surface electrodes. 10 patients were studied 1 day before, 10 days and 6 months after radical prostatectomy. Significant changes of amplitude and frequency characteristics could not be found in rest and during the stationary intervals of maximal contraction. But after the operation in all patients changed the activation pattern within the interval of increasing muscle contraction. The mean and median frequency decreased significantly (Friedman-test, p < 0.001). This was interpreted as a problem of intramuscular coordination. After physiotherapy urinary incontinence was cured or improved. The typical activation pattern of dyscoordination was not more evident after 6 months.