Spatial distribution of surface EMG on trapezius and lumbar muscles of violin and cello players in single note playing

Musicians activate their muscles in different patterns, depending on their posture, the instrument being played, and their experience level. Bipolar surface electrodes have been used in the past to monitor such activity, but this method is highly sensitive to the location of the electrode pair. In this work, the spatial distribution of surface EMG (sEMG) of the right trapezius and right and left erector spinae muscles were studied in 16 violin players and 11 cello players. Musicians played their instrument one string at a time in sitting position with/without backrest support. A 64 sEMG electrode (16x4) grid, 10mm inter-electrode distance (IED), was placed over the middle and lower trapezius (MT and LT) of the bowing arm. Two 16x2 electrode grids (IED=10mm) were placed on the left and right erector spinae muscles. Subjects played each of the four strings of the instrument either in large (1bow/s) or detaché tip/tail (8bows/s) bowing in two sessions (two days). In each of two days, measurements were repeated after half an hour of exercise to see the effect of exercise on the muscle activity and signal stability. A “muscle activity index” (MAI) was defined as the spatial average of the segmented active region of the RMS map. Spatial maps were automatically segmented using the watershed algorithm and thresholding. Results showed that, for violin players, sliding the bow upward from the tip toward the tail results in a higher MAI for the trapezius muscle than a downward bow. On the contrary, in cello players, higher MAI is produced in the tail to tip movement. For both instruments, an increasing MAI in the trapezius was observed as the string position became increasingly lateral, from string 1 (most medial) toward string 4 (most lateral). Half an hour of performance did not cause significant differences between the signal quality and the MAI values measured before and after the exercise. The MAI of the left and right erector spinae was smaller in the case of backrest support, especially for violin players. Back muscles of violin and cello players were activated asymmetrically, specifically in fast movements (detaché tip/tail). These findings demonstrate the sensitivity and stability of the technique and justify more extensive investigation following this proof of concept

Estimation of load sharing among muscles acting on the same joint and Applications of surface electromyography

The force produced by a specific muscle cannot be measured and what is measured is the total force provided by all the active muscles acting on a joint, including agonists and antagonists. The first part of this work (chapter 3) addresses the issue of load sharing by proposing two possible approaches and testing them. The second part (chapter 4 and 5) addresses two applications of surface EMG focusing on the study of a) muscle relaxation associated to Yoga sessions and b) the activation of muscle of the back and shoulder of musicians playing string instruments (violin, viola and cello). In both parts the element of innovation is the use of two dimensional electrode arrays and of techniques based on EMG Imaging. The objectives of this work are presented and explained in chapter 1 while the basic concepts of surface EMG are summarized in chapter 2. Different EMG-based muscle force models found in the literature are explained and discussed. Two renowned amplitude indicators in surface EMG (sEMG) studies are the average rectified value (ARV) and the root mean square (RMS). These two amplitude indicators are computed over a defined time window of the recorded signals to represent the muscle activity. The advantages and disadvantages of RMS and ARV are compared and discussed for a simple sinusoid as well as for more complex signals (simulated motor unit action potential detected by high density electrode grid). The results show that RMS is more robust to the sampling frequency than ARV. In this thesis, starting from the simulation of a single fiber and of a group of fibers (motor unit), it is shown that inter electrode distance (IED) greater than10 mm causes aliasing. Aliasing is a source of error in sEMG map interpretation or decisions that are made by automatic algorithms such as those providing image segmentation for the identifications of regions of interest. Chapter 2 discusses three segmentation algorithms (K-means, h-dome, watershed) and compares them in order to find the most suitable method. Results reveal that among the three mentioned algorithms, watershed provides most accurate segmentation for the simulated ARV maps. Chapter 3 presents a mathematical model that is associated to the monotonic Force-EMG relation. A possible non-linear relationship between the EMG and force or torque is presented. A system of "M" equations is obtained by performing "M" measurements at "M" different force levels in isometric conditions. The solutions of such system of equations are the values for each muscles. Two different approaches were investigated for finding the solutions of the system, which are: a) Analytical-Graphical Approach (AGA) and b) Numerical Approach (NA) consisting of error minimization (between the total estimated and measured force) applying optimization algorithms. The AGA was used to find the model parameters of each muscle contributing to the force production on a joint by finding the intersection of those surfaces that can be obtained from sequential substitutions of the model parameters in the equations corresponding to each contraction level. In simulation studies, the AGA graphically shows that there is more than one solution to the load sharing problem even for the simplest theoretical case (i.e. a joint spanned by only two muscles). The second approach, based on minimization of the mean square error between the measured and the total estimated force or torque (with "N" muscles involved) provides an estimate of the model parameters that in turn provides the force contributions of the individual muscles. The optimization algorithms can find the solutions of our system made of non-linear equations (see chapter 3). Starting from different point (initial conditions), different solutions can be found, as predicted by the AGA approach for the two-muscle case. The main conclusion of this study is that the load sharing strategy is not unique. Chapter 4 discusses the application of surface electromyography to a single case study of Yoga relaxation to show the feasibility of measurements. The effect of yoga relaxation on muscle activity (sEMG amplitude), as well as on mean and median frequencies and muscle fiber's conduction Velocity, is discussed in this chapter. No changes in the sEMG activity pattern distribution were found for the same task performed before and after applying yoga relaxation technique. However, myoelectric manifestations of fatigue were smaller after relaxation and returned to the normal pattern after the recovery phase from relaxation. Further studies are justified. Chapter 5 describes results and discusses the spatial distribution of muscle activity over the Trapezius and Erector Spinae muscles of musicians playing string instruments. In chapter 5, the effect of backrest support in sitting position during playing cello, viola, and violin on the muscle activity index of upper and lower Trapezius muscle of the bowing arm, upper Trapezius muscle of non-bowing arm, left and right Erector Spinae muscles is investigated. Two professional players (one cello and one viola) and five student players (one cello, three violin and one viola) participated in this study. The muscle activity index (MAI) was defined as the spatial average of RMS values of the muscle active region detected by watershed segmentation for Trapezius muscles (left and right), and thresholding technique (70% of the maximum value) for left and right Erector Spinae muscles. It was found that the MAI is string (note) dependent. Statistical difference (p < 0:05) between the MAIs of left Erector Spinae muscle during playing with and without backrest support was observed in four (out of five) student players. No statistical differences were observed on the muscle activity of Trapezius (bowing and no-bowing arms) during playing with and without backrest support in different types of bowing for all musicians. In conclusion, this work addresses a) the issue of spatial sampling and segmentation of sEMG using 2D electrode arrays, b) two possible approaches to the load-sharing issue, c) a single-case study of Yoga relaxation and d) the distribution of muscle activity above the Trapezius and Erector Spinae muscles of musicians playing string instruments. Previously unavailable knowledge has been achieved in all these four studies

Surface Electromyography for Direct Vocal Control

This paper introduces a new method for direct control using the voice via measurement of vocal muscular activation with surface electromyography (sEMG). Digital musical interfaces based on the voice have typically used indirect control, in which features extracted from audio signals control the parameters of sound generation, for example in audio to MIDI controllers. By contrast, focusing on the musculature of the singing voice allows direct muscular control, or alternatively, combined direct and indirect control in an augmented vocal instrument. In this way we aim to both preserve the intimate relationship a vocalist has with their instrument and key timbral and stylistic characteristics of the voice while expanding its sonic capabilities. This paper discusses other digital instruments which effectively utilise a combination of indirect and direct control as well as a history of controllers involving the voice. Subsequently, a new method of direct control from physiological aspects of singing through sEMG and its capabilities are discussed. Future developments of the system are further outlined along with usage in performance studies, interactive live vocal performance, and educational and practice tools

Proficiency-aware systems

In an increasingly digital world, technological developments such as data-driven algorithms and context-aware applications create opportunities for novel human-computer interaction (HCI). We argue that these systems have the latent potential to stimulate users and encourage personal growth. However, users increasingly rely on the intelligence of interactive systems. Thus, it remains a challenge to design for proficiency awareness, essentially demanding increased user attention whilst preserving user engagement. Designing and implementing systems that allow users to become aware of their own proficiency and encourage them to recognize learning benefits is the primary goal of this research. In this thesis, we introduce the concept of proficiency-aware systems as one solution. In our definition, proficiency-aware systems use estimates of the user's proficiency to tailor the interaction in a domain and facilitate a reflective understanding for this proficiency. We envision that proficiency-aware systems leverage collected data for learning benefit. Here, we see self-reflection as a key for users to become aware of necessary efforts to advance their proficiency. A key challenge for proficiency-aware systems is the fact that users often have a different self-perception of their proficiency. The benefits of personal growth and advancing one's repertoire might not necessarily be apparent to users, alienating them, and possibly leading to abandoning the system. To tackle this challenge, this work does not rely on learning strategies but rather focuses on the capabilities of interactive systems to provide users with the necessary means to reflect on their proficiency, such as showing calculated text difficulty to a newspaper editor or visualizing muscle activity to a passionate sportsperson. We first elaborate on how proficiency can be detected and quantified in the context of interactive systems using physiological sensing technologies. Through developing interaction scenarios, we demonstrate the feasibility of gaze- and electromyography-based proficiency-aware systems by utilizing machine learning algorithms that can estimate users' proficiency levels for stationary vision-dominant tasks (reading, information intake) and dynamic manual tasks (playing instruments, fitness exercises). Secondly, we show how to facilitate proficiency awareness for users, including design challenges on when and how to communicate proficiency. We complement this second part by highlighting the necessity of toolkits for sensing modalities to enable the implementation of proficiency-aware systems for a wide audience. In this thesis, we contribute a definition of proficiency-aware systems, which we illustrate by designing and implementing interactive systems. We derive technical requirements for real-time, objective proficiency assessment and identify design qualities of communicating proficiency through user reflection. We summarize our findings in a set of design and engineering guidelines for proficiency awareness in interactive systems, highlighting that proficiency feedback makes performance interpretable for the user.In einer zunehmend digitalen Welt schaffen technologische Entwicklungen - wie datengesteuerte Algorithmen und kontextabhängige Anwendungen - neuartige Interaktionsmöglichkeiten mit digitalen Geräten. Jedoch verlassen sich Nutzer oftmals auf die Intelligenz dieser Systeme, ohne dabei selbst auf eine persönliche Weiterentwicklung hinzuwirken. Wird ein solches Vorgehen angestrebt, verlangt dies seitens der Anwender eine erhöhte Aufmerksamkeit. Es ist daher herausfordernd, ein entsprechendes Design für Kompetenzbewusstsein (Proficiency Awareness) zu etablieren. Das primäre Ziel dieser Arbeit ist es, eine Methodik für das Design und die Implementierung von interaktiven Systemen aufzustellen, die Nutzer dabei unterstützen über ihre eigene Kompetenz zu reflektieren, um dadurch Lerneffekte implizit wahrnehmen können. Diese Arbeit stellt ein Konzept für fähigkeitsbewusste Systeme (proficiency-aware systems) vor, welche die Fähigkeiten von Nutzern abschätzen, die Interaktion entsprechend anpassen sowie das Bewusstsein der Nutzer über deren Fähigkeiten fördern. Hierzu sollten die Systeme gesammelte Daten von Nutzern einsetzen, um Lerneffekte sichtbar zu machen. Die Möglichkeit der Anwender zur Selbstreflexion ist hierbei als entscheidend anzusehen, um als Motivation zur Verbesserung der eigenen Fähigkeiten zu dienen. Eine zentrale Herausforderung solcher Systeme ist die Tatsache, dass Nutzer - im Vergleich zur Abschätzung des Systems - oft eine divergierende Selbstwahrnehmung ihrer Kompetenz haben. Im ersten Moment sind daher die Vorteile einer persönlichen Weiterentwicklung nicht unbedingt ersichtlich. Daher baut diese Forschungsarbeit nicht darauf auf, Nutzer über vorgegebene Lernstrategien zu unterrichten, sondern sie bedient sich der Möglichkeiten interaktiver Systeme, die Anwendern die notwendigen Hilfsmittel zur Verfügung stellen, damit diese selbst über ihre Fähigkeiten reflektieren können. Einem Zeitungseditor könnte beispielsweise die aktuelle Textschwierigkeit angezeigt werden, während einem passionierten Sportler dessen Muskelaktivität veranschaulicht wird. Zunächst wird herausgearbeitet, wie sich die Fähigkeiten der Nutzer mittels physiologischer Sensortechnologien erkennen und quantifizieren lassen. Die Evaluation von Interaktionsszenarien demonstriert die Umsetzbarkeit fähigkeitsbewusster Systeme, basierend auf der Analyse von Blickbewegungen und Muskelaktivität. Hierbei kommen Algorithmen des maschinellen Lernens zum Einsatz, die das Leistungsniveau der Anwender für verschiedene Tätigkeiten berechnen. Im Besonderen analysieren wir stationäre Aktivitäten, die hauptsächlich den Sehsinn ansprechen (Lesen, Aufnahme von Informationen), sowie dynamische Betätigungen, die die Motorik der Nutzer fordern (Spielen von Instrumenten, Fitnessübungen). Der zweite Teil zeigt auf, wie Systeme das Bewusstsein der Anwender für deren eigene Fähigkeiten fördern können, einschließlich der Designherausforderungen , wann und wie das System erkannte Fähigkeiten kommunizieren sollte. Abschließend wird die Notwendigkeit von Toolkits für Sensortechnologien hervorgehoben, um die Implementierung derartiger Systeme für ein breites Publikum zu ermöglichen. Die Forschungsarbeit beinhaltet eine Definition für fähigkeitsbewusste Systeme und veranschaulicht dieses Konzept durch den Entwurf und die Implementierung interaktiver Systeme. Ferner werden technische Anforderungen objektiver Echtzeitabschätzung von Nutzerfähigkeiten erforscht und Designqualitäten für die Kommunikation dieser Abschätzungen mittels Selbstreflexion identifiziert. Zusammengefasst sind die Erkenntnisse in einer Reihe von Design- und Entwicklungsrichtlinien für derartige Systeme. Insbesondere die Kommunikation, der vom System erkannten Kompetenz, hilft Anwendern, die eigene Leistung zu interpretieren

Effects of muscle fatigue, pain and warm-up on elite performance

Human performance is a broad research domain with both direct and translational applications to a wide array of medical and occupational fields. Study of elite performance, specifically, allows us to discover the extent and limits of human capability and its response to dysfunction. Investigation of elite performance has typically focussed on populations of sport athletes, however has recently expanded to include instrumental musicians based on emerging evidence highlighting the similar physical demands of athletes and instrumental musicians. Various intervention strategies are often employed to enhance performances and prevent injuries in instrumental musicians, yet quality scientific evidence regarding the efficacy of such strategies is especially scarce in this population. Accordingly, this thesis was designed to address knowledge gaps regarding three domains related to performance enhancement and injury prevention in elite performance populations, with particular attention given to domains most likely to provide practical benefits for instrumentalists: warm-up, pain, and fatigue. Investigation of warm-up strategies began with a systematic review of upper body warm-ups (Chapter 2), with the initial goal of using this review to provide a basis for a novel randomised controlled trial investigation of warm-up in elite violinists. The review revealed that no evidence exists to support any warm-up strategies for either performance enhancement in submaximal activities or injury prevention, despite widespread advocacy for the benefits of warm-up in populations of submaximal athletes such as instrumental musicians. High load dynamic warm-ups were shown to improve maximal strength and power performance only. Thus, with no clear ‘gold standard’ warm-up, an investigation of warm-up on muscle activity, musical performance, and perceived exertion in elite violinists was designed using a range of warm-up strategies: instrument-specific, muscular, and cardiovascular (Chapter 3). The results of this trial were consistent with findings of the upper body warm-up systematic review—none of the investigated warm-ups significantly impacted muscle activity or musical performance. All three investigated warm-ups, however, resulted in an acute decrease in perceived exertion compared to a control group. Epidemiological literature has revealed that an extremely large proportion of musicians— often reported to be >80%--experience pain or other physical symptoms over the course of their careers. Less clear, however, is the acute impact of continued playing with these physical symptoms on the musicians’ technique and biomechanics. A cross-sectional analysis of EMG data collected during the warm-up RCT (Chapter 3) was undertaken to investigate the impact of pain and other physical symptoms (e.g. cramps, tingling, numbness) on muscle activity levels in elite violinists. The results suggested that proximal and distal right arm symptoms may be the cause or be the result of differential bowing mechanics (Chapter 4). Finally, effective fatigue management permits consistent achievement of peak performance with minimal injury risk, yet our ability to manage acute fatigue is limited by an inability to reliably predict its onset. Further, acute fatigue has only been sparselent investigated in elite performance populations. To address this gap, a meta-analysis of available electromyographic (EMG) and demographic data from studies investigating fatigue protocols in healthy populations was conducted (Chapter 5). This meta-analysis yields the first comprehensive, data-driven predictive model for muscle fatigue; this model takes into account age, sex, muscle fibre type, contraction force, and initial EMG amplitude and provides an evidencebased foundation for fatigue management programmes in elite performance populations. Further, a novel and robust univariate relationship between EMG change rate and time to task failure during fatiguing contractions was discovered. In addressing knowledge gaps regarding the impact of warm-up, pain, and fatigue on muscular and/or musical performance, this thesis has raised further questions regarding warm-up efficacy, proposed differential mechanisms for biomechanical responses to proximal and distal physical symptoms, and presented a comprehensive framework for muscle fatigue prediction. In addition to providing a basis for future research, these findings will immediately benefit elite performers, musician and athlete, and will also have translational benefits to occupational and rehabilitative domains

High Density Surface Electromyography Activity of the Lumbar Erector Spinae Muscles and Comfort/Discomfort Assessment in Piano Players:Comparison of two chairs

Introduction: At a professional level, pianists have a high prevalence of playing-related musculoskeletal disorders. This exploratory crossover study was carried out to assess and compare quantitatively [using high density surface electromyography (HDsEMG)], and qualitatively (using musculoskeletal questionnaires) the activity of the lumbar erector spinae muscles (ESM) and the comfort/discomfort in 16 pianists sitting on a standard piano stool (SS) and on an alternative chair (A-chair) with lumbar support and a trunk-thigh angle between 105° and 135°. Materials and Methods: The subjects played for 55 min and HDsEMG was recorded for 20 s every 5 min. For the quantitative assessment of the muscle activity, the spatial mean of the root mean square (RMS(ROA)) and the centroid of the region of activity (ROA) of the ESM were compared between the two chairs. For the qualitative assessment, musculoskeletal questionnaire-based scales were used: General Comfort Rating (GCR); Helander and Zhang’s comfort (HZc) and discomfort (HZd); and Body Part Discomfort (BPD). Results: When using the A-chair, 14 out of 16 pianists (87.5%) showed a significantly lower RMS(ROA) on the left and right side (p < 0.05). The mixed effects model revealed that both chairs (F = 28.21, p < 0.001) and sides (F = 204.01, p < 0.001) contributed to the mean RMS(ROA) variation by subject (Z = 2.64, p = 0.004). GCR comfort indicated that participants found the A-Chair to be “quite comfortable,” and the SS to be “uncomfortable.” GCR discomfort indicated that the SS caused more numbness than the A-Chair (p = 0.05) and indicated the A-Chair to cause more feeling of cramps (p = 0.034). No difference was found on HZc (p = 0.091) or HZd (p = 0.31) between chairs. Female participants (n = 9) reported greater comfort when using the A-Chair than the SS (F = 7.09, p = 0.01) with respect to males. No differences between chairs were indicated by the BPD assessment. Conclusion: It is concluded that using a chair with lumbar support, such as the A-chair, will provide greater comfort, less exertion of the ESM and less discomfort than the standard piano stool

Longitudinal tracking of physiological state with electromyographic signals.

Electrophysiological measurements have been used in recent history to classify instantaneous physiological configurations, e.g., hand gestures. This work investigates the feasibility of working with changes in physiological configurations over time (i.e., longitudinally) using a variety of algorithms from the machine learning domain. We demonstrate a high degree of classification accuracy for a binary classification problem derived from electromyography measurements before and after a 35-day bedrest. The problem difficulty is increased with a more dynamic experiment testing for changes in astronaut sensorimotor performance by taking electromyography and force plate measurements before, during, and after a jump from a small platform. A LASSO regularization is performed to observe changes in relationship between electromyography features and force plate outcomes. SVM classifiers are employed to correctly identify the times at which these experiments are performed, which is important as these indicate a trajectory of adaptation

Perceptions of discrepancies between intentions and outcomes during music practice : differences among musicians with varied levels of experience and expertise

Errors are an inherent and necessary part of learning in all dimensions of human activity. In order to effectively encode and refine procedural memories, learners must experience attempts to accomplish goals, perceive discrepancies between the results of their attempts and their intended outcomes, and adjust their behavior to accommodate those discrepancies. The extent to which music practice results in positive changes in the quality of performance and extent of performers’ facility is in part a function of the precision of learners’ physical and auditory goals and learners’ discrimination of discrepancies between those goals and the outcomes their movements produce. We designed three experiments to examine musicians’ perceptions of their own others’ practice. In Experiment 1, immediately after recording individual practice sessions, high school, college, and professional musicians listened to their recordings and pressed a computer key to mark moments of discrepancy between what they had intended while practicing and what they heard on the recordings; in Experiment 2, the high school and professional participants from Experiment 1 repeated the task 2 years later; in Experiment 3, high school and professional participants heard practice recordings of four other violinists’ practice (two artist-level experts and two competent students), and pressed the key each time they heard a discrepancy between what they heard on the recordings and what they would have intended had they been the practicer. In Experiment 1, the mean rates of keypresses did not differ among the high school, undergraduate, graduate, and professional participants, although there were large within-group variances. When the high school and professional participants in Experiment 1 returned after 2 years and performed the same task with their original recordings, high school participants marked significantly more discrepancies, but the mean rate of keypresses among professionals did not increase. In Experiment 3, professionals marked significantly more discrepancies than did high school participants, but and the mean rates of keypresses within each group did not differ among recordings by professionals and high school musicians. These results are consistent with the notion that the precision of performance goals and the acuity of perceptual discrimination are central features of musical expertise.Musi

Musical Instrument Ergonomics in Violin and Piano Performance

The compatibility of the instrument with human physical abilities and characteristics is one of the principles in ergonomics. Inadequate instrument set-ups and sizes that mismatch the player’s physical attributes is frequently cited as one of the risk factors contributing to the development of playing-related musculoskeletal disorders (PRMDs) in violin and piano performers. For violinists, playing in a sustained asymmetric posture is inevitable and it has been observed that the left upper limb, which is the side that supports the instrument, is predominantly symptomatic in upper string players (violinists and violists). The use of adaptive accessories, such as a chin rest and/or a shoulder rest, has been proposed to be a way to improve the interface between the instrument and the player. For pianists, a “one-size-fits-all” keyboard has been the available industry standard with respect to the size of the keyboard in modern piano manufacturing, teaching and performing. However, recent demographic evidence proposes that this standardised piano keyboard discriminates against many pianists who have relatively smaller hand sizes. Controversies persist in best methods to ergonomically fit the instrument to the player among players and pedagogues of both these instruments, and no reviews to date have been conducted to determine whether a collection of evidence to support ergonomic ideals exists. This doctoral thesis presented the synthesis of work on investigating ergonomics in violin and piano performance and addressing knowledge gaps regarding optimising the interface between the instrument and the player. A systematic review of this topic was undertaken in Chapter 2. The results revealed that only scarce evidence with heterogeneity and low quality of methodology available on instrumental ergonomics in violin and piano performance. An observational study on interaction between hand span and different sizes of keyboards on muscle activity in pianists was conducted in Chapter 3 to investigate the biomechanical responses under ergonomic modifications, while hand size was identified as a potential risk factor for PRMDs (Chapter 2). The results of this experiment showed less muscular loads in pianists while they were playing on a matched size of keyboard regarding their hand spans, suggesting a compatible interface between the player and instrument can enhance performance biomechanics. Chapter 4 and 5 presented an interview study conducted to explore the factors that contribute to optimising the instrument-player interface in violin playing while the lack of comprehensive understanding of violin set-up was shown in Chapter 2. In Chapter 4, interview data was extracted in a way to present how the violin instrument should fit to a player. The results suggested there were fundamental inconsistencies in the use of physical elements (e.g. violin accessories and position the violin instrument) and the attitudes and beliefs towards instrument set-up while participants held onto different sources of knowledge. On the other hand, comfort and budget were commonly seen as the considerations in selecting the ergonomic set-up. Chapter 5 presents the findings from the aspect of how violinists should fit with their instruments, showing the biomechanics greatly varies but having a neutral posture may be the common aim in violin playing. It is also revealed the phenomenon that violinists tended to prioritise musical performance over monitoring their own posture and movement. Results in both Chapter 4 and 5 showed teacher plays an important role in either pedagogically providing ergonomic suggestions or working with body health professionals on improving a performance interface in violinists, and the process can be time-consuming. The data presented in this thesis showed the complexity of optimising the interface between the musical instrument and the player. From the investigations on violinists and pianists, interdisciplinary collaborations and crossover trainings in the professionals are recommended so that musicians are able not only to be trained with adequate ergonomic supports but to sustain their desirable musical outcomes. Future research building upon the findings of this thesis will further facilitate the inclusion of ergonomics in the industry of musical performance