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Hintergrund: Sozial benachteiligte Schwangere sind in besonderem Maße vulnerabel. Sie befinden sich wie alle Schwangeren in einer biographischen Übergangssituation und tragen zusätzlich die mit ihrem sozialen Status assoziierten Gesundheitsrisiken. In diesem Zusammenhang stellt insbesondere die Geburtsvorbereitung als gesundheitsfördernde Maßnahme ein wichtiges niedrigschwelliges Angebot der Gesundheitsförderung dar. Denn durch diese kann bereits vor der Geburt die Unterstützung, Beratung und Vernetzung der betroffenen Mädchen und Frauen erfolgen. Die Verbesserung der Inanspruchnahme von Unterstützungsangeboten wie der Hebammenbetreuung setzt Detailwissen um die Bedürfnisse der angesprochenen Personengruppe voraus. Deren Erfassung ist daher ein wesentlicher Schwerpunkt dieser Studie.
Methode: In der qualitativen Studie werden sowohl Frauen und Mädchen in schwierigen Lebenssituationen (n=19) zu ihren Bedürfnissen und Erfahrungen in der Schwangerschaft als auch Expertinnen, Familienhebammen und ein Sozialpädagoge retrospektiv teilstrukturiert befragt (n=7). Ergänzt werden die Aussagen durch Angebotsanalysen aus ausgewählten Städten und Gemeinden (n=7). Die Auswertung der Studie ist angelehnt an die Technik der Grounded Theory.
Ergebnisse: Die Bedürfnisse der befragten Frauen und Mädchen in der Schwangerschaft sind komplex und weisen in ihren speziellen Ausprägungen besondere thematische Schwerpunkte auf. Durch die meist prekären Lebensverhältnisse stehen Sicherheitsbedürfnisse im Vordergrund. Soziale Beziehungen und die Rollenfindung als Mutter sind gleichfalls wichtige Themen, weil die Frauen von Diskriminierung betroffen sind oder diese befürchten. Das Informationsbedürfnis bezieht sich schwerpunktmäßig auf gegenwärtige Phänomene und Erfahrungen. Viele der geäußerten Bedürfnisse werden sowohl an die Menschen des sozialen Umfelds als auch an Mitarbeiter der Beratungsstellen oder Akteure des Gesundheitswesens adressiert. Hebammen bieten sich durch ihre spezielle Arbeitsstruktur insbesondere dann als Ansprechpartner an, wenn die Kontakte zu Familienmitgliedern oder den Menschen des direkten sozialen Umfelds unsicher sind. Übliche Geburtsvorbereitungskurse treffen nur bedingt die Interessen der Befragten und bringen das Risiko einer Ausgrenzung durch die Gruppe mit sich. Die Interviews mit den Expertinnen sowie die Angebotsanalysen zeigen außerdem, dass die Vernetzung der Professionen des Gesundheits- und Sozialwesens und eine Überweisung zu passgenauen Angeboten nur unzureichend realisiert sind.
Ausgewählte Empfehlungen: Die speziellen Bedürfnisse der schwangeren Frauen und Mädchen in besonderen Lebenssituationen bedürfen einer inhaltlich abgestimmten Vernetzung von Ärzten, Hebammen und Beratern. Geburtsvorbereitungskurse sollten neben den üblichen curricularen Inhalten die Chance berücksichtigen, dass Frauen eine neue soziale Rolle im unkomplizierten Beisammensein mit anderen neu definieren und erproben können. Die thematischen Schwerpunkte sollten das Wachstum des Kindes und zeitnahe Erfahrungen in den Vordergrund stellen.
In this paper, we evaluate the application of Bayesian Optimization (BO) to discrete event simulation (DES) models. In a first step, we create a simple model, for which we know the optimal set of parameter values in advance. We implement the model in SimPy, a framework for DES written in Python. We then interpret the simulation model as a black box function subject to optimization. We show that it is possible to find the optimal set of parameter values using the open source library GPyOpt. To enhance our evaluation, we create a second and more complex model. To better handle the complexity of the model, and to add a visual component, we build the second model in Simio, a commercial off-the-shelf simulation modeling tool. To apply BO to a model in Simio, we use the Simio API to write an extension for optimization plug-ins. This extension encapsulates the logic of the BO algorithm, which we deployed as a web service in the cloud.
The fact that simulation models are black box functions with regard to their behavior and the influence of their input parameters makes them an apparent candidate for Bayesian Optimization (BO). Simulation models are multivariable and stochastic, and their behavior is to a large extent unpredictable. In particular, we do not know for sure which input parameters to adjust to maximize (or minimize) the model’s outcome. In addition, the complex models can take a substantial amount of time to run.
Bayesian Optimization is a sequential and self-learning algorithm to optimize black box functions similar to as we find them in simulation models: they contain a set of parameters for which we want to identify the optimal set, they are expensive to evaluate, and they exhibit stochastic noise. BO has proven to efficiently optimize black box functions from varius disciplines. Among those, and most notably, it is successfully applied in machine learning algorithms to optimize hyperparameters.
SimBO is a flexible framework for optimizing discrete event-driven simulations (DES) using sequential optimization algorithms. While specifically designed for Bayesian Optimization (BO) in the context of DES, SimBO can be applied to any black-box problem with other optimization algorithms. The framework consists of four encapsulated components - the black-box problem, the sequential optimization algorithm, a database for experiment configuration and results, and a web-based graphical user interface - that communicate via well-defined interfaces. Each component can be run in different environments, allowing for cooperation between different hardware- and software configurations. In our research context, SimBO’s architecture enabled BO algorithms to be run on a high-performance cluster with GPU support, while the simulation is executed on a local Windows machine using the Simio simulation software. The framework’s flexibility also makes it suitable for evolving from a research-focused tool to a production-ready, cloud-based optimization tool for modern algorithms.
Rationale: Three-dimensional (3D) motion analysis has proved helpful in the diagnosis of different musculoskeletal syndromes and identifying injurious movement patterns in high string players. Furthermore, an optoelectronic 3D motion capture system allows an accurate and objective assessment of upper body posture and motion during violin and viola performance. However, no reference upper body model of high string players has been proposed as yet. Moreover, a more physiological shoulder model that separates the joints of the shoulder complex has not been reported. Especially in view of given the role of the scapula in the normal movement of the humerus, it cannot be disregarded when evaluating musculoskeletal strain in the shoulder.
The International Society of Biomechanics recommends definitions of joint coordinate systems for the report of upper body joint motion using anatomical landmarks as reference for the placement of surface markers. Using markers on the skin for some of the proposed locations is, however, inappropriate when an instrument is being played. There are skin movement artifacts, e. g. caused by the movement of the scapula underneath the skin, whereas some markers interfere with the instrument on the shoulder or might be occluded by the bowing arm in motion.
Purpose: The aim of this study was to develop a marker-based method for quantifying 3D upper body kinematics of high string players and to demonstrate its clinical feasibility in violin and viola performance. The method is intended to provide an objective evaluation of high string players’ motor strategies, especially in the shoulder complex, while minimizing skin movement artifacts, marker occlusions and limitations in instrument placement.
Methods: A custom marker set was developed consisting of thirty-one single markers to define the anatomical coordinate systems of sixteen upper body segments including the pelvis, thorax, spine and head, as well as both scapulae, upper arms, forearms and hands. Twenty-one of these markers as well as two pre-built and four custom-made rigid marker clusters were used for tracking the segment motions.
Twelve professional violinists without history of musculoskeletal or neurological problems were recruited for assessing the clinical feasibility of the method. They were asked to perform a single sequence of two consecutive musical notes on each of two adjacent strings (G- and D-string) in real time, played at 50 bpm with tempo audibly regulated by a metronome, and using a standardized violin and bow. The participants played up- and down-bow alternately using the whole length of the bow.
A custom biomechanical model was applied to the motion capture data and the rotation angles of fifteen joints were calculated. The location of each glenohumeral joint rotation center was computed by upper arm movements with respect to the scapula based on a functional method. For a description of the motion patterns, minimum, maximum and range of angular motion were averaged across participants for each string and rotation. Inter-subject variability was assessed by calculating the standard deviation (SD) at each sample of the angle-time series between participants for each rotation and for both strings. Then SD was averaged over sequences for each rotation and string. For comparing mean rotation angles between strings over time, random effect models were used.
Results: The highest range of motion was observed in the right elbow flexion and right wrist flexion/extension. Also, high ranges of motion (> 10°) were found in all right glenohumeral rotations and right wrist deviation and pronation/supination. In conclusion, lumbar and thoracic spine, thorax, neck, and left upper limb were quite static, while large motion occurred in the right upper limb during up and down bowing.
Most rotation angles showed a reasonable inter-subject variability except for left and right glenohumeral plane of elevation as well as left glenohumeral internal/external rotation, and left and right wrist pronation/supination (> 10°).
Significant differences in the rotation angles between G- and D-string bowing were detected especially in the left wrist and right shoulder joints.
Conclusions: This is the first study that used quantitative 3D analysis to explore the upper body kinematics of high string players during performance, providing a detailed view of the motor control in the shoulder as well as in the lumbar and thoracic spine. The biggest advantage over previously published methods is the more physiological shoulder and spine models while providing a simple application.
The method was found to give consistent motion patterns across participants and to be sensitive to differences between adjacent strings. Although the method appears to be valid, more rigorous validation is necessary. Since there is no gold standard with which we could compare results, we were only able to assess the clinical feasibility. We believe that our method represents a good compromise between accuracy and practicability for clinical application.
Due to the inclusion of multi-segmented shoulder and spine models, it will improve understanding of the motor strategies adopted by high string players and may contribute to injury prevention, diagnosis and treatment.
Rationale:
Instrumentalists often suffer from playing-related (neuro-)musculoskeletal disorders (PRMDs). Most common PRMDs in string players are related to upper-body regions. Motion analysis has proven to be helpful in the evaluation of functional disorders. It was already shown that it is a valid and clinically feasible tool for accurate, repeatable, and objective assessments of functional movement in string players. Thus, it may guide clinicians to improvements in injury prevention, diagnosis, and treatment. Nevertheless, its application in clinical consultation is still very uncommon. For this reason, there is a lack of well-established motion analysis protocols for the examination of PRMDs in string players using advanced biomechanical instruments in clinical settings.
Purpose:
To demonstrate the development and application of a motion analysis protocol for the evaluation of functional upper-body movements in violinists, violists, and cellists in a clinical setting for the investigation of PRMDs.
Approach:
The protocol was to be integrated into a clinical reasoning process for testing clinical hypotheses and evaluating treatment outcomes in physiotherapy. As a starting point, a primary clinical question was defined, and then, specific upper-body symptom regions as well as measurement parameters (relative rotation angles and muscle activities over time) were identified. Subsequently, involved segments, joints, and muscles were assorted. For quantification of upper-body kinematics a novel, marker-based method was used which provides multi-segmented shoulder and spine models while providing simple application. Based on that, a comprehensive mechanical model of the upper body as well as the associated coordinate systems and rotation sequences were specified. This further guided both, the definition of a custom-made marker set as well as the selection and placement of surface electrodes. Furthermore, required static and functional calibration trials as well as movement tasks for functional assessment were specified. Finally, advanced approaches, such as a comprehensive kinematic model and functional determination of joint centers and axes were established for extraction. Then, outcome parameters and their form of representation were determined for further analysis and interpretation.
The application of the method first includes the selection of segments, joints, and muscles to examine – originating from one or more clinical (working) hypotheses or symptom regions. This drives the configuration and placement of required surface markers and electrodes. Then, the required calibration and functional movement trials are executed. After measurement, the outcome parameters get extracted and analyzed. Based on the results the hypothesis is discarded or verified.
Content:
The method was applied to a violinist (female; 18 years old; 13 years of experience; practicing 2 to 3 hours per day, 7 days per week) with playing-related demands in the left cervical-shoulder-arm region.
Subjective findings indicated that the pain regularly occurred after 30 minutes of playing fast or difficult musical pieces. Physical examination showed that strength testing of left serratus anterior muscle caused pain, lower trapezius muscles seemed weak, forearm muscles were sensitive to pressure, movement of the cervical spine to the left was reduced, and upper limb neural tension test was noticeable.
This led to the following working hypothesis: Neck-related arm pain with neurodynamic component and motor control problem in the scapulothoracic region. Thus, left-sided cervical-shoulder-arm region was selected for functional examination.
Optoelectronic motion capture system and surface electromyography were used for data collection. Static and function calibration trials as well as functional assessment trials (chromatic scale with different tempi) were conducted. Afterwards, data was further processed, and outcome parameters were extracted.
Results showed that greater tempo and pain had an impact on the rotation angles and muscle activities. They led to less overall joint movement and range of motion, to less muscle activity in the forearm muscles, and to greater activity inputs in the scapulothoracic muscles. Overall, greater tempo and pain led to a different motor program which verified the working hypothesis.
The procedure was repeated after treatment (four appointments over one week) with manual therapy, training, and education. The pre-/post-interventional comparison showed changes in the motor program. There was noticeable higher mean activity in upper trapezius and deltoid muscles and simultaneously less in the remaining ones. In addition, only marginal differences in ranges of motion and muscle activity inputs were found between tempi. The playing style appeared to be more stable now. Overall, it appeared that nearly the same motor program was used for each tempo.
Clinical Implications:
Potential applications are intraindividual evaluations of simultaneously joint and muscular function in string players during clinical consultation. It is intended to contribute to the diagnosis of PRMDs in terms of an objective, comprehensive and yet clinically feasible diagnostic assessment as well as pre-post-intervention outcome evaluation.
Nonetheless, motion analysis must be used with care in clinical decision making. Motion data is subject to both, intraindividual variations, and measurement errors. In addition, the smallest clinically relevant changes are not clear yet. Therefore, results should only be interpreted together with other clinical findings.