For this feasibility study, a cross-sectional design was selected. Participants were first-semester undergraduate students at the University of Alberta, Edmonton, Canada. They were tested once without follow-up. Inclusion criteria were: 1) enrolled in first-semester as a full-time undergraduate student majoring in music (case) or in any other faculty at the University of Alberta (control), 2) voluntary participation, 3) over the age of 16. Exclusion criteria were: 1) diagnosis of neurological, orthopaedic or psychological condition, 2) diagnosis of infections or systemic disease, 3) regular consumption of pain medication or medication for mental health diagnosis, 4) varsity athlete, 5) for controls only, enrollment in selected courses (e.g. studio lessons) from the music department, where a grade is assigned for playing an instrument.
Recruitment and testing took place from 2016 until 2018, each semester between September and November for 2016-18 fall cohorts (3), and between March and May for the 2018 spring cohort (1). Seventy-nine students contacted the researchers to indicate interest in participation. Data from ten participants were excluded for the following reasons: a non-music student taking music courses; a varsity athlete; participants with mental health diagnoses; participants choosing to withdraw without stating reasons; and participants lost to follow-up. Data from a total of 69 students were included in the analysis, of which 19 were music students and 50 were non-music/control students. No sample size calculation was conducted for this feasibility study. Ethics approval for this study was obtained from the Research Ethics Boards at the Osnabrück University of Applied Sciences and the University of Alberta.
This feasibility study used the following procedure: students were recruited through posters displayed across campus, on social media (Twitter and Facebook), through a campus-wide email distribution system, and via flyers distributed in-person in a first-year music class. Potential participants were informed that they would receive a $5 coffee gift card for participation, plus one additional gift card for referring additional eligible participants.
Initial eligibility of participants was confirmed via email. Eligible participants were then invited to be tested at the investigator’s lab on campus. On testing day, the procedure, as well as inclusion and exclusion criteria, were explained to the participant. Eligible participants were then asked to provide written informed consent. Testing started with participants completing a baseline questionnaire asking general demographic information and history of pain and musculoskeletal complaints. This was followed by additional questionnaires assessing self-reported mental and physical well-being. The second part of the protocol included physical testing of range of motion (ROM), mechanosensitivity, core strength, and general mobility. At the end of the assessment, participants were briefed about their performance. Overall, testing took approximately 70 minutes. All assessments were performed by an investigator who was either a trained physiotherapist, occupational therapist or an occupational therapy student. Every investigator received a minimum of 2 hours of instruction/training for the assessments.
This pilot study adhered as closely as possible to the study protocol used by Ballenberger et al. to allow for comparability and to test feasibility of the protocol in a different geographical and cultural setting (16). Furthermore, through continuous communication with the authors of the parent study in Germany, refinements to the original protocol were reflected in our study protocol at the earliest convenience. This paper describes the final protocol used. Changes are discussed in the discussion.
Assessment of physical and mental health
The original participant questionnaire was translated from German into English by a native German speaker who is fluent in both languages. This study aimed to compare music and non-music students. In the initial cohort, music students answered a playing-related pain questionnaire. Neither music nor control students, however, were asked to answer any questions about general musculoskeletal pain prevalence. For better comparison, 20 questions about general pain were added before recruitment of the third cohort. Those questions were based on the general pain questions used in the German parent study.
Health-related Quality of life
To screen health-related quality of life, we used the RAND 12 questionnaire, which is free and does not require a license. This makes the test more user-friendly for replication of the study and future implementation in clinical settings. Furthermore, a custom scoring algorithm that is more appropriate for chronic conditions was employed, which does not rely on the basic assumption that physical and mental health component scores are not related (18). Test-retest reliability is reported to be excellent (ICC=0.78) and adequate (ICC=0.60) for physical and mental health composites, respectively (19).
Initially, the parent study in Germany used the Stress-Coping-Inventory (SCI) (16). An optional, more versatile, mental health screening questionnaire was found in the 21-item Depression Anxiety Stress Scales (DASS-21), which –unlike the SCI – has also been translated into multiple languages. The DASS-21 screens and distinguishes between the three mental health dimensions of depression, anxiety and stress (20). It demonstrates good internal consistency of 0.82-0.97, for both clinical and non-clinical populations (21, 22).
Core strength was assessed using four tests: a full plank, lateral planks on the right and left sides, and the Biering-Sørensen test for extensor endurance (23). Both the Biering-Sørensen test and plank tests have excellent inter-rater reliability (ICC = 0.8-0.99 and ICC = 0.95, respectively) (23, 24). Investigators demonstrated the correct positioning and allowed participants to try. Participants were then asked to hold each position until fatigued or needing to stop for any other reason. Other reasons participants in this study gave for stopping included pain, discomfort or vigorous shaking. A 30 second break between planks was given to eliminate confounding fatigue. Any position change was verbally corrected once; any further correction led to termination of the test.
To assess general mobility/ hypermobility, the Beighton score and the Sitting-Rising Test (SRT) were utilized. The Beighton score assigns a score of 0 to 9 reflecting general mobility (25). Participants performed four movements bilaterally, which were assessed by the investigator. The SRT assesses general mobility out of 10-points. Participants were asked to sit cross-legged on the floor, and rise with minimal support (26, 27). For any additional support needed, points were deducted from a 10-point scale. Both tests have good intra- and inter-rater reliability (26; 28).
Kenny Music Performance Anxiety Inventory
Music Performance Anxiety was evaluated using the Kenny Music Performance Anxiety Inventory (KMPAI-R). The inventory was first developed in 2004 and is the only validated tool that not only measures cognitive, behavioral, and physiological aspects of performance anxiety, but also “underlying psychological vulnerability” (29). The latest, revised version consists of 40 items, subdivided into eight domains. A participant can score a maximum of 240 points, where a higher score indicates more severe MPA symptoms. Questions address playing-related anxiety and the influence of different external sources. It has shown excellent internal consistency (Cronbach’s Alpha =0.94) (30). The questionnaire is musician-specific, and was therefore only answered by music students.
To test mechanical pressure pain threshold, the same nine bilateral testing points as the original protocol by Ballenberger et al. were assessed (16). For the first cohort, a mechanical algometer (Pain Diagnostics & Thermography, Italy) was used, which was then exchanged for a digital model (FDIX Wagner Instruments, Greenwich, CT, USA). Each point was tested three times, with a recovery period of 5 seconds in between.
Playing-related Musculoskeletal Disorders and pain/complaints interfering with daily living
Musicians answered the Musculoskeletal Pain Intensity and Interference Questionnaire for Musicians (MPIIQM). The tool, containing 13 questions, evaluates musicians’ current playing-related health concerns (31). It generates two sub scores for pain interference (0-40) and pain intensity (0-50) (32). There are currently no cut-off scores established for this tool. It has adequate internal consistency and test-retest reliability (31).
IBM SPSS, version 25, and Microsoft Excel 2013 were used to analyse collected data. Alpha was set at p<0.05. Most characteristics were not normally distributed, so non-parametric tests were chosen, using Mann-Whitney U test and the Chi-square-test for continuous and categorical variables, respectively. A preliminary analysis showed that musician and control groups were comparable in terms of both age and gender, and therefore, data were not adjusted for these variables. Effect size r was calculated by dividing the z-value by square root of N (33).