The Effects of Using an Ergonomic Chinrest When Playing the Violin

Study Overview
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Brief Summary
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A one-day crossover randomised trial was conducted to compare violinists using an ergonomic chinrest (EC) with do-as-usual on muscle activation, kinematics and sound. After two weeks of testing the EC, self-perceived evaluations on comfort, performance, sound, neck alignment and muscle tension were reported in a questionnaire between EC and do-as-usual. The main question is to answer if: the EC is superior compared to do-as-usual and gives a more aligned neck posture and less muscle tension/dynamic muscle activity the EC is subjectively evaluated as better than do-as-usual regarding self-perceived comfort, performance and sound

Detailed Description
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The purpose of this study is to investigate the measurement of neck kinematics, muscle activation and sound when using EC and a usual chinrest and, additionally, their self-reported experience of neck alignment, muscle tension, sound experience, performance, and comfort. It is a crossover, block randomised (block sizes of 4) and within-subjects experimental design performed in one day. The design was made to compare an ergonomic chinrest used with a low shoulder rest (EC) with preferred chin and shoulder rest (do-as-usual) in a randomised order and the effect on muscle activation, kinematics and sound. The study also includes a two-week familiarisation period testing the EC before the test day (crossover design). After these two weeks, a questionnaire was given to register self-reported performance, comfort and sound experience. Furthermore, the participants were asked in an SMS about what ergonomic equipment they used after half a year (the EC, do-as-usual or other equipment). On the test day, all participants played with both setup an excerpt of a music piece (second movement from W. A. Mozart's violin concerto no. 5 in A major), The required sample size was estimated based on a previous feasibility study of either being in an awkward or neutral position with the head. We aimed to recruit 38 professional violinists. A professional violinist was defined as having finished the music conservatory with the violin as the main subject or attending school enrolled in the last years (master/soloist player). The protocol was initial feasibility tested, and we report this study using the Consolidated Standards of Reporting Trials (CONSORT) 2010 extension to randomised crossover trials.

Official Title
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Self-reported and Objectively Measured Muscle Tension and Neck Kinematics in Violinists Playing With an Ergonomic and Usual Chinrest: a Randomised Crossover Study

Conditions
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Ergonomics

Intervention / Treatment
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* Device: Ergonomic chinrest used with low shoulder rest (EC)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older speak and write fluently Danish or English Professional violinists No severe pain symptoms in the neck or upper extremities (<3) scored on a numeric rating scale from 0 (no pain) to 10 (worst perceived pain). Exclusion Criteria: medical conditions that could influence the test result (pacemaker or life-threatening health disorders) trauma on the upper cervical spine or upper extremities within the last 12 months previous or planned shoulder/neck operation severe eczema on the neck and upper extremities.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: We designed a crossover, block randomised (block sizes of 4) and within-subjects experimental design.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ergonomic chinrest used with low shoulder rest (EC)<br>Participants will play the violin using the ergonomic chinrest with a low Kun Super shoulder rest (EC) | Device: Ergonomic chinrest used with low shoulder rest (EC)<br>* Participants will play the violin using the ergonomic chinrest with a low Kun Super shoulder rest (EC) for two weeks before the test day (crossover study), measuring upper body kinematic and muscle activity. The novel ergonomic chinrest (Kréddle®, Wyoming, US) is fully adjustable to accommodate each violinist's body type and performance style: regarding height, rotation and tilting. The low Super Kun shoulder rest has been adjusted to be in the lowest position for all legs attached to the violin before the violinists received it. All participants was told not to adjust the shoulder rest but adjust the chinrest.<br>|
| No Intervention: Do-as-usual<br>On the test day (crossover study), participants will play with the usual preferred chin and shoulder rest. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Upper body kinematic was recorded by the device called Vicon | Neck movement data were collected with Vicon measured in degrees of movement in three anatomical planes: 1) head flexion, 2) head lateral bend, 3) head rotation, 4) trunk flexion, 5) trunk rotation and 6) arm abduction. This measurement was recorded on the test day for both setups while playing a music piece. Furthermore, a test was made on the ROM (head) in a sitting position for all participants before measuring the kinematics during the music piece. | One day | 
| Electromyography was recored with Myon | Wireless sEMG (Myon 320, AG, Switzerland) was used and placed to measure muscle activity bilaterally from the upper trapezius muscles (UT), upper neck extensor muscles (NE), sternocleidomastoideus muscles (SCM) and on the right medial and left anterior deltoideus muscle (DT). This measurement was recorded on the test day for both setups. | One day | 
| Sound was recorded with Olympus LS-10 stereo digital recorder | Sound measurement was recorded on the test day for both setups | One day | 
| Self-reported performance score | Three questions were used for an overall performance score: Have you had difficulty with (within the last 14 days) 1) playing your violin? 2) using your normal technique when playing? 3) playing as well as you would like to? The questions were answered on a 5-point Likert scale from no to impossible. These questions were given after the two-week familiarisation period. | Two weeks | 
| Self-reported comfort score | Five questions are used for the overall comfort score: How comfortable was (the last 14 days) 1) playing with EC-/ EC+, 2) the height of EC (with your chosen adjustment), 3) the configuration of EC that you have chosen, and 4) the size of the EC chinplate? , 5) the chinrest surface against your skin? The question was answered on a 5-point Likert scale from very comfortable to very uncomfortable. These questions were given after the two-week familiarisation period. | Two weeks | 
| sound quiz | A quiz with six audio files in a randomised order was sent a month after the test day. The quiz was simple: Do you play using Kréddle (the EC): yes, no, don't know. | one month | 
| Diary | Each day during the two-week familiarisation period the violinists had to fill in a diary: written user feedback that will be categorised into positive, negative or neutral feedback. Furthermore about the EC adjustment and their confidence level. The adjustment was recorded if they found an adjustment that worked ('Yes', 'No', 'Not yet'). The confidence level when playing with EC was reported on a 5-point Likert scale (5= very confident, 1=not very confident). 'Very confident' was defined as if the violinist could play the music sheets sent to them also after a break of several days | Two weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Adherence | Adherence to the protocol was recorded from the self-administrated two-week diary. Adherence was counted as the number of days playing with the EC out of the two weeks. | Two weeks | 
| Compliance | Compliance to the protocol was recorded from the self-administrated two-week diary. Compliance for playing with EC was hours played out of total playing time. | Two weeks | 
| Follow-up on which product they are using | After the crossover test day the study ends, but the participants have to answer after a half a year if the are still using EC, do-as-usual or another new setup and if it because they participated in this project. This was answered by a SMS message. | 6 month | 
| Antroprometrics | Body measurements were taken on the test day: neck length, arm length, height and shoulder width | One day | 
| Instrument measurement | On the test day the measurement of the length of the instrument, the shoulder rest height and chin rest height was taken for both setups (EC and do-as-usual) | One day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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crossover design, neck kinematic, muscle workload, violin playing, performance, comfort