A biomechanical approach to improve health among professional violinists using a novel ergonomic chinrest: The ergonomics of playing the violin

Violinists constitute a substantial proportion of classical musicians in symphony orchestras. Especially, violin playing involves asymmetrical seating posture and prolonged, repetitive work, which includes static muscle activity. As a result, violinists are particularly prone to playing-related musculoskeletal disorders, experiencing higher pain rates ranging from 64.1% to 90% compared to other musicians. The consequences of such disorders have wideranging effects on individuals and society. Inability to perform on their instrument can result in sickness absence and, in the worst case, early termination of employment, leading to increased healthcare expenses and reduced productivity.

Many violinists use supportive ergonomic equipment such as chinrests and shoulder rests to alleviate discomfort and improve the interface between the violin and the player, especially in the left shoulder and neck muscles. However, studies have shown that even with the widespread use of such equipment, many violinists still experience pain. Furthermore, there is a lack of consensus on how to effectively use these products to decrease muscle activity or change neck posture. Additionally, the understanding of violinists' perceptions regarding the usability of these products in terms of performance and comfort is limited.

This PhD dissertation commenced with a systematic online search for an ergonomic chinrest (EC) that largely incorporates all necessary features to accommodate a player's anthropometrics, especially an aligned neck posture. Subsequently, three studies were conducted with the following objectives: 1) examining the preliminary feasibility and acceptability of the selected EC, 2) investigating the feasibility of playing the violin with the EC, with or without a low shoulder rest, and 3) investigating the effects on upper body kinematics and muscle activity when using the EC compared to the participants' usual chinrest and
shoulder rest. Additionally, the user experience of the EC was explored to identify potential barriers and facilitators.

The first study involved a case study on the feasibility of using the EC for six weeks. Data on usage, performance, comfort, pain, and fatigue were collected. The instructional materials were found not to be feasible, requiring the implementation of online guidance for installation and usage from the product developer. Compliance with using the EC was high, and positive feedback was received regarding its effects on performance and comfort. However, the case experienced pain and fatigue throughout the six weeks. Still, the case reported no pain or fatigue at the end and expressed being positive toward using the EC in the future.

Based on the case study results, pain-free violinists were recruited for the following studies. The second was a feasibility study conducted over two weeks involving six violinists. It aimed to assess the usability of the EC utilising questionnaires evaluating various factors such as usage, performance, comfort, adjustment, confidence, sound quality, and written user feedback. The EC demonstrated high use; however, playing without a shoulder rest was deemed unfeasible due to significantly lower performance, longer confidence-building time, and more negative feedback. Additionally, all six participants met the compliance criterion
when playing with a shoulder rest, whereas two participants did not meet the criterion when playing without it. Consequently, the EC with a low shoulder rest was chosen for further testing.

The third and final study investigated the effects of the EC on upper-body muscle activity, neck kinematics and the user experience of EC. This study involved 38 professional violinists and used electromyography, three-dimensional motion capture and questionnaires. The comparison between the EC and the participants' usual chinrest and shoulder rest revealed only minor differences, including less left rotation of the head (3.3°), increased neck extension (1.3°), and slightly lower muscle activity (0.5-1.0 %MVE). No significant biomechanical differences were observed, and overall, the EC maintained static muscle activity (4-10
%MVE) across all muscles. The user experience of the EC demonstrated a solid drive to improve posture, reduce muscle tension, and enhance performance. Although usability issues such as product appearance, adjustment time, and sound impact were identified, 37% of participants expressed intentions to continue using the EC after the study.

In conclusion, this particular EC proved feasible for use with a low shoulder rest. However, no substantial changes were found in neck posture or muscle activity compared to the participants' usual chinrest and shoulder rest. Various usability issues were identified, which can inform the design process of the EC or other ergonomic products. Therefore, this specific EC cannot be recommended as a superior alternative to violinists' usual ergonomic chinrests. Nevertheless, developing solutions supporting individuals' needs remains crucial to ensure their satisfaction.

Future studies may explore other innovative ergonomic solutions, alternative interventions such as micro-breaks, or incorporating active and specific training during rehearsals. Furthermore, it is important to investigate and understand the changes in health behaviour among violinists and identify the necessary factors to enhance their well-being.