Upper trapezius muscle stiffness among musicians with and without playing-related musculoskeletal disorders: a cross-sectional study

Abstract

Background

Increased muscle stiffness (MS) in the upper trapezius (UT) has been shown to be correlated with pain in some populations, but knowledge regarding altered MS in musicians affected by playing-related musculoskeletal disorders (PRMDs) remains limited. The primary aim of this study was to investigate whether MS is altered in musicians with PRMDs. A further aim was to explore the associations between MS and musicians’ features.

Methods

A total of 60 musicians from the Conservatory of Southern Switzerland and the Orchestra della Svizzera italiana participated in the study. The assessment procedure included a self-report questionnaire on background and lifestyle, practice habits, PRMD characteristics (i.e., presence, intensity, location, and extent), physical activity and perceived health, along with a bilateral evaluation of MS in the UT using the MyotonPRO (Muomeetria, Tallinn, Estonia).

Results

Of the 60 participants, 28 musicians (47%) reported ongoing PRMDs, with higher pain prevalence in the UT, especially on the left side. MS in the UT did not differ significantly between musicians with and without PRMDs. However, significant differences were observed in preparatory exercises (𝑍 = -2.1, p < 0.05) and rest breaks during practice sessions (𝑍 = -2.8, p < 0.01). Furthermore, positive correlations were identified between MS and perceived effort (ρ = 0.6, p < 0.01), playing-related disability (ρ = 0.5, p < 0.01), and physical activity level (ρ = 0.4, p < 0.01). Conversely, a negative correlation was found between MS and the physical component of perceived health (ρ= -0.7; p < 0.01).

Conclusions

Although no statistically significant difference was found in MS between the PRMD and non-PRMD groups, significant associations between MS and musician-related features were detected. Future research should prioritise collaborative longitudinal studies between musical and scientific communities, with the aim of monitoring musicians over time and developing a deeper understanding of the relationships between specific musical practices, individual characteristics, and MS.

Background

The rigorous demands of playing a musical instrument at a high level require musicians to perform countless repetitive fine motor movements during long hours of practice sessions each day, within a highly competitive context. In addition, musical instruments are typically played in ergonomically demanding postures, exposing the muscles of the neck, trunk, and upper extremities to overuse [1] and repetitive work strain [2, 3]. Consequently, many musicians suffer from playing-related musculoskeletal disorders (PRMDs), which interfere with their ability to play [4] and negatively impact their participation in musical activities such as rehearsals, daily practice, and performance. The neck and shoulder area has been frequently reported as one of the most affected regions [5–8]. Recently, neck and shoulder pain has been shown to be related to higher muscle stiffness (MS) in the upper trapezius (UT) muscle among other populations [9–11]. It is plausible that similar conditions can be found among musicians because of the repetitive load while playing [2, 3, 12, 13], which is potentially associated with the development and persistency of PRMDs and therefore possibly implicated in preventive or treatment strategies.

MS reflects the mechanical properties of muscle tissue such as elasticity, tone, and resistance to deformation, but its relationship with musculoskeletal health has yet to be established [11, 14, 15]. Nevertheless, the relationship between MS and pain has been implicated in populations subject to repetitive movements and prolonged physical demands [16]. For musicians, the pressure to perform at a high level, along with the demands of rehearsals, auditions, and concerts, can contribute to psychophysical stress, affecting both playing technique and overall wellbeing [17]. Therefore, assessing MS might provide an opportunity to better understand playing-related problems. For instance, it might be speculated that high levels of MS might be involved in the risk of developing chronic musculoskeletal conditions, potentially jeopardising a musician’s career [18].

Recent advancements in measurement technologies, such as the MyotonPRO (Muomeetria, Tallinn, Estonia), have enabled reliable, cost-effective, and non-invasive quantification of MS [19, 20]. This device has demonstrated good to excellent intra-rater and inter-rater reliability for assessing muscle tone, stiffness, and elasticity [20]. While its application in the study of musicians remains limited, the MyotonPRO offers promise for advancing the understanding of MS in this population. To date, only one study has explored MS among musicians, in which tensiomyography was used to measure changes in the UT muscle before and after myofascial induction therapy of the masticatory muscles [21]. This highlights the need for further research to investigate the relationship between MS and PRMDs in musicians. The main aim of this study was to determine whether MS in the UT muscle is altered in musicians with PRMDs compared with musicians without PRMDs. A further objective was to investigate potential associations between MS and the characteristics of musicians, including demographic, music-related, and health-related features.

Methods

This study employed a descriptive cross-sectional design and was conducted and reported in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines.

Participants

All musicians enrolled at the University School of Music of the Conservatory of Southern Switzerland (Conservatorio della Svizzera italiana - CSI) or employed in the Orchestra della Svizzera italiana (OSI) were invited to participate in this study between October and November 2023.

Musicians were eligible if they were: (i) adults (i.e., 18 years of age); (ii) Bachelor of Arts students and Master of Arts students; (iii) students attending gap year programs or continuing education courses; and (iv) professional musicians employed in a professional orchestra.

To exclude musicians with severe health conditions unrelated to musical performance that could confound self-reported outcomes (i.e., pain perception, perceived effort, and disability), participants reporting skin lesions or sensory disturbances in the UT, as well as severe, disabling neurological and/or rheumatic conditions (e.g., fibromyalgia syndrome, rheumatoid arthritis, focal dystonia) or traumatic injuries in the past 12 months, as well as severe psychological conditions (e.g., diagnosed severe borderline personality disorders) in the past 12 months or upper limb and/or spinal surgery.

The participants were divided into two groups on the basis of their response to the PRMD question developed by Zaza et al. [4]: the PRMD group (musicians with a PRMD) and the non-PRMD group (musicians without any current PRMD). The sample size calculation was based on previous studies assessing MS [22, 23], assuming a pooled standard deviation of 45 N/m and aiming to detect a difference of 35 N/m between groups. To achieve a statistical power of 80% with a two-sided significance level of 5%, a minimum of 26 participants per group (i.e., 52 total) was needed. The non-PRMD group was selected to match the PRMD group as closely as possible in terms of occupation (e.g., student/professional), gender (e.g., women, men, other), and type of instrument (e.g., played with one or both arms elevated or neutral position) to control for potential confounding factors.

Procedures

Musicians were recruited through an in-person presentation conducted by the principal investigator and/or via e-mail with the support of the secretary offices of the approached institutions. The e-mail contained information about the study, a participant information sheet with the consent form, the link to a web-based questionnaire site using the environment provided by Qualtrics^® and a link to a scheduling tool (i.e., Calendly^®) to express the availability for a further physical assessment procedure in person. The latter was conducted to assess MS and was arranged to take place across the CSI and OSI at a pre-arranged date and time at a single appointment.

The research project was granted ethical approval by the Cantonal Research Ethics Committee of Canton Ticino (Switzerland) (Ref. CE 4447, BASEC 2023 − 01616). The study was conducted in accordance with the principles outlined in the Declaration of Helsinki, Good Clinical Practice, the Human Research Act, and the Human Research Ordinance.

Outcome measures

The questionnaire included items related to musicians’ demographic and lifestyle information (i.e., gender, age, main occupation, weight and height, smoking status, and sleeping habits), as well as music-related information (i.e., main musical instrument, years of experience, number of hours of practice per week, whether preparatory exercises and breaks were included during each practice session [Yes/No response], and perceived exertion while playing, assessed using a 0–10 numerical rating scale).

Additionally, PRMDs were defined in accordance with Zaza et al. [4] as pain, weakness, lack of control, numbness, tingling, or other symptoms that interfere with a musician’s ability to play their instrument at their accustomed level, and participants were screened for such symptoms experienced during the preceding week using this definition. In the case of PRMDs, participants were asked to shade their pain on a female or male body chart with two different views (frontal and dorsal) printed on paper, using the web-based software Sketch Your Pain (SYP) (https://syp.spslab.ch) for scanning and processing via QR codes [24, 25]. In addition, participants were asked to indicate the intensity of their symptoms on a numerical rating scale (NRS) from 0 (no pain) to 10 (worst possible pain) [26].

Additionally, the officially validated Italian versions of three standardised questionnaires were used to assess health-related outcomes:

• The Performing Arts Section of the Disabilities of the Arm, Shoulder and Hand Outcome Measure (PAS-DASH) consists of 5 items designed to evaluate playing-related disability; scores range from 0 (no disability) to 100 (most severe disability), with higher scores indicating greater playing-related disability [27–30].

• The short form of the International Physical Activity Questionnaire (IPAQ-SF) comprises seven items assessing the frequency and duration of vigorous, moderate, and walking activities undertaken over the preceding seven days. Total physical activity is expressed in MET-minutes per week, with higher scores indicating greater levels of physical activity. On the basis of IPAQ-SF scores, physical activity levels are further categorised as high, moderate, or low [31, 32].

• Finally, the 12-Item Short Form Health Survey (SF-12) includes 12 questions evaluating perceived health across two main components: the physical component score (PCS) and the mental component score (MCS). Scores for each component range from 0 to 100, with higher scores indicating better perceived physical or mental health [33, 34].

MS was subsequently measured with the MyotonPRO, which is a hand-held, non-invasive, painless, and easy-to-use technology, with good to excellent intra-rater and inter-rater reliability in assessing muscle [20] and tendon stiffness [35]. This tool produces a lighted, brief mechanical impulse to the skin overlying the targeted muscle, delivering a force of 0.4 N on the underlying soft tissue for 15 ms to cause muscle deformation. The probe of a handheld MyotonPRO device was placed perpendicular to the skin surface overlying the muscles and constant pressure was applied. The ability of soft tissues to resist deformation caused by MyotonPRO is assessed via an acceleration graph that represents the damped natural oscillation of the tissue. Dynamic stiffness, measured in N/m, is determined by multiplying the peak acceleration of the oscillation by the probe’s mass and dividing it by the maximum tissue displacement. Higher values indicate stiffer tissue [35].

MS was assessed over four pre-defined anatomical points bilaterally in the UT, each spaced 2 cm apart, centred on the midpoint between the spinous process of the seventh cervical vertebra (C7) and the most lateral aspect of the acromion (see Fig. 1). A custom-made transparent plastic template, specifically designed for this study, was employed to standardise the placement of four measurement points, each spaced 2 cm apart around the midpoint of the muscle belly of the UT.

Fig. 1.

Measurement points for the assessment of MS. For a standardised marking of the measurement points, a self-produced template was used on the calculated mid-point (orange) of the upper trapezius muscle that was calculated between the spinous process of the seventh cervical vertebra (C7) and the most lateral aspect of the acromion. Four measurement points were bilaterally centred around the mid-point, each 2 cm apart. The MyotonPRO is held vertically, and provides five mechanical impulses for each measurement point, with a frequency of 15ms and a constant gentle pressure of 0.4 N

The measurements were taken on the same chair, in an upright position, without leaning against the back of the chair, with the arms extended to the side of the thighs, with 0° shoulder flexion. Standardised instructions were given to the participants to remain relaxed, maintain a natural resting posture, look straight ahead, and refrain from speaking, in order to ensure consistency and minimise voluntary muscle tension.

In all the instances, two raters were involved. A physiotherapist responsible for locating the measurement points underwent specialised training in anatomical landmark identification, alongside supervised calibration sessions with the MyotonPRO device to ensure both intra- and inter-rater reliability. Furthermore, a researcher performing the MyotonPRO measurements received dedicated training in device operation and standardised assessment protocols to maintain methodological rigour and reliability.

Statistical analysis

Descriptive statistics were used to systematically summarise all the variables. For categorical variables, absolute and relative frequency distributions were presented. For continuous variables, the distribution was assessed using the Shapiro-Wilk normality test. Variables with a normal distribution (p > 0.05) are reported as means and standard deviations (SDs), whereas variables with a non-normal distribution (p ≤ 0.05) are presented as medians and interquartile ranges (IQRs).

Using SYP, the analysis of pain extent, expressed as the number of pixels coloured inside the frontal and dorsal body charts (i.e., the total area of pain for each participant), and pain frequency maps to indicate the most frequently reported location of pain across the entire sample were computed for women and men separately.

To explore differences between the groups in terms of MS, independent samples t-tests for the left and right sides were performed. In addition, a paired samples t-test was used to compare the differences between corresponding points on the right and left sides of the body.

A total of 21 variables were analysed in this study. These variables include demographic characteristics (i.e., age, gender, hand dominance, main occupation), music-related characteristics (i.e., musical instrument played, years of experience, weekly hours of practice, perceived exertion while playing, use of preparatory exercises, and taking breaks during practice sessions), health-related outcome measures (i.e., body mass index, hours of sleep per night, smoking status, PAS-DASH score, IPAQ-SF score, SF-12 physical health component, SF-12 mental health component and pain characteristics, such as ventral pain extent, dorsal pain extent, ventral pain intensity, and dorsal pain intensity). The selection of the 21 variables considered was informed by previous literature [3, 7, 8, 36–43], which highlighted the relevance of factors such as playing habits, physical activity, perceived exertion, and general health in relation to musculoskeletal health in musicians.

Furthermore, the Spearman correlation test was used to estimate the correlation between the mean MS (i.e., the mean stiffness score calculated bilaterally across all eight measurement points for each participant) and continuous or ordinal variables (e.g. age, years of experience, hours of practice, perception of effort during execution, body mass index, hours of sleep, playing-related disability score as measured by the PAS-DASH questionnaire, IPAQ-SF score, intensity and extent of pain, scores regarding physical and mental health of the SF-12). Correlation coefficients (Spearman’s rho) were interpreted according to the following thresholds: values between 0.10 and 0.30 were considered low, values between 0.31 and 0.50 were considered moderate, and values above 0.50 were considered strong correlations [44].

Finally, the Mann-Whitney U test was used to analyse whether the mean stiffness significantly changed according to the categorical variables (e.g. gender, occupation, instrument, preparatory exercises and break, hand dominance, smoking).

Results

A total of 60 musicians participated in the study, with a response rate of approximately 26% for the CSI and 33% for the OSI. In total, the percentage of participants with self-reported PRMDs was 47% (n = 28), whereas approximately 53% (n = 32) did not report current PRMDs and were thus allocated to the non-PRMD group.

Overall, participants with a chronic PRMD were the majority (n = 19; 68% of participants with PRMDs).

The descriptive features of the participants are described in the following tables, including demographic variables (see Table 1), music-related variables (see Table 2) and health-related variables (see Table 3).

Table 1.

Descriptive statistics of the demographic variables

Variable		PRMD (n = 28)	non-PRMD (n = 32)	Total (n = 60)
		n (%)	n (%)	n (%)
Gender	Women	15 (48.4)	16 (51.6)	31 (51.7)
	Men	13 (44.8)	16 (55.2)	29 (48.3)
	Other	0 (0.0)	0 (0.0)	0 (0.0)
Age	median (IQR)	24.0 (4.0)	25.0 (9.2)	24.0 (5.0)
Hand dominance	Right	24 (44.4)	30 (55.6)	54 (90.0)
	Left	4 (100.0)	0 (0.0)	4 (6.7)
	Ambidextrous	0 (0.0)	2 (100.0)	2 (3.3)
Main occupation	Bachelor’s students	5 (71.4)	2 (28.6)	7 (11.7)
	Master’s students	20 (51.3)	19 (48.7)	39 (65.0)
	Continuing education students	2 (66.7)	1 (33.3)	3 (5.0)
	Professionals	1 (9.1)	10 (90.9)	11 (18.3)

Table 2.

Descriptive statistics of the music-related variables

Variable		PRMD (n = 28)	non-PRMD (n = 32)	Total (n = 60)
		n (%)	n (%)	n (%)
Instrument	Bassoon	2 (66.7)	1 (33.3)	3 (5.0)
	Cello	1 (20.0)	4 (80.0)	5 (8.3)
	Clarinet	2 (100.0)	0 (0.0)	2 (3.3)
	Double bass	2 (100.0)	0 (0.0)	2 (3.3)
	Flute	2 (28.6)	5 (71.4)	7 (11.7)
	French Horn	0 (0.0)	2 (100.0)	2 (3.3)
	Guitar	1 (100.0)	0 (0.0)	1 (1.7)
	Oboe	1 (100.0)	0 (0.0)	1 (1.7)
	Percussion	0 (0.0)	2 (100.0)	2 (3.3)
	Piano	3 (33.3)	6 (66.6)	9 (15.0)
	Viola	5 (71.4)	2 (28.6)	7 (11.7)
	Violin	8 (47.1)	9 (52.9)	17 (28.3)
	Voice	1 (50.0)	1 (50.0)	2 (3.3)
Years of experience	median (IQR)	13.5 (5.8)	17.0 (9.0)	16.0 (9.0)✝
Hours of practice per week	median (IQR)	30.0 (19.1)	33.8 (7.8)	30.0 (14.0)
Perceived exertion while playing	median (IQR)	5.0 (2.0)	4.5 (1.8)	5.0 (2.0)
Preparatory exercises	Yes	14 (53.8)	12 (46.2)	26 (43.3)
	No	14 (41.2)	20 (58.8)	34 (56.7)
Breaks during practice	Yes	14 (58.3)	10 (41.7)	24 (40.0)
	No	14 (38.9)	22 (61.1)	36 (60.0)

✝Data available for 31 subjects in the non-PRMD group and 59 subjects overall (one subject did not respond to this question)

Table 3.

Descriptive statistics of the health-related variables

Variable		PRMD (n = 28)	non-PRMD (n = 32)	Total (n = 60)
		n (%)	n (%)	n (%)
BMI [kg/m 2]	median (IQR)	21.5 (1.9)	22.1 (3.7)	21.8 (3.1)
Hours of sleep	median (IQR)	7.5 (1.4)	7.0 (1.0)	7.3 (1.0)
Smoking	Yes	7 (77.8)	2 (22.2)	9 (15.0)
	No	21 (41.2)	30 (58.8)	51 (85.0)
Playing-related disability [PAS-DASH]	median (IQR)	58.3 (53.7)	31.3 (31.3)	43.8 (27.0)
Physical activity participation levels [IPAQ-SF score]	High	8 (57.1)	6 (42.9)	14 (23.3)
	Moderate	9 (47.4)	10 (52.6)	19 (31.7)
	Low	11 (40.7)	16 (59.3)	27 (45.0)
Perceived health [SF-12]
Physical component	median (IQR)	47.2 (19.6)	55.4 (6.4)	53.0 (11.9)
Mental component	median (IQR)	37.3 (14.1)	44.8 (12.0)	42.2 (13.5)
Pain
Ventral pain extent (%)	median (IQR)	1.7 (1.7)	-	1.7 (1.7)
Dorsal pain extent (%)	median (IQR)	5.6 (5.7)	-	5.6 (5.7)
Ventral pain intensity	median (IQR)	4.8 (4.0)	-	4.8 (4.0)
Dorsal pain intensity	median (IQR)	5.5 (4.4)	-	5.5 (4.4)

BMI Body Mass Index, IPAQ-SF International Physical Activity Questionnaire – Short Form, PAS-DASH Performing Arts Section of the Disabilities of the Arm, Shoulder and Hand Outcome Measure, SF-12 Short-form Health survey questionnaire

Furthermore, Fig. 2 shows the pain frequency maps, where the perceived painful regions of the body for women and men for the frontal and dorsal views of the body are reported. Overall, neck/shoulder, thoracic and lumbar regions were marked most frequently, particularly among women, who presented a higher frequency and a broader distribution of PRMDs. It is important to note that these maps do not represent the number of individuals experiencing symptoms, but rather the anatomical areas where pain was most frequently reported by those who experienced PRMDs.

Fig. 2.

Pain frequency maps generated by superimposing the pain drawings of all participants included in the study (n = 60). Pain frequency maps were generated for men and women separately and for both the dorsal and frontal views. The colour grid indicates both the number and the percentage of individuals who reported pain in the specific area. Dark red represents the most frequently reported area of pain

The PRMD group (n = 28) and the non-PRMD group (n = 32) were compared in terms of MS across four measurement points on both the left and right sides of the body. The results of the independent samples t-tests are shown in Table 4.

Table 4.

Comparison of upper trapezius muscle stiffness (N/m) between the PRMD and non-PRMD groups at four measurement points on the left and right sides of the body

	Total (n = 60)	PRMD (n = 28)	non-PRMD (n = 32)	Mean Difference btw groups	T-test sig. p-value
	mean (SD)
Left
Point L1	334.6 (57.3)	328.9 (54.1)	339.6 (60.2)	10.7	0.942
Point L2	335.1 (55.8)	330.5 (53.7)	339.1 (58.1)	8.6	0.826
Point L3	348.7 (61.6)	334.3 (45.2)	361.3 (71.3)	27.0	0.158
Point L4	351.3 (66.5)	339.9 (61.9)	361.2 (69.8)	21.3	0.585
Right
Point R1	346.2 (55.2)	340.3 (47.2)	351.3 (61.7)	11.0	0.268
Point R2	348.4 (59.0)	341.3 (53.0)	354.6 (63.9)	13.3	0.544
Point R3	340.3 (61.4)	329.5 (58.7)	349.8 (63.1)	20.3	0.698
Point R4	354.4 (64.8)	343.1 (61.7)	364.3 (66.7)	21.2	0.712
Mean MS
	344.6 (53.1)	335.7 (46.1)	352.4 (58.2)	16.7	0.433

Independent samples t-tests were used to compare the groups. p-values indicate the significance of differences between groups at each measurement point. The values are reported as means with standard deviations (SDs)

On both sides, no significant differences were found between the groups (p > 0.05). These results suggest that there were no statistically significant differences between the PRMD and non-PRMD groups for MS at either the left or right points.

In addition, a paired samples t-test was used to compare the differences between the points on the right and left sides. The results revealed a statistically significant difference between points L1 and R4 (t(59) = −3.93, p < 0.001), with a mean difference of −19.82 (95% CI: −29.90, −9.74). However, no significant differences were observed between L2 and R3 (t(59) = −1.03, p = 0.309), L3 and R2 (t(59)  = 0.07, p = 0.943), or L4 and R1 (t (59) = 0.92, p = 0.361).

As significant differences were observed at only two bilateral points, the mean MS—calculated as the average stiffness score across all measurement points for each participant—was used in Spearman’s rank correlation tests (for continuous and ordinal variables) and the Mann–Whitney U test (for categorical variables). The statistically significant results are presented in Table 5 (i.e., correlations) and 6 (i.e., group comparisons).

Table 5.

Statistically significant correlations between mean muscle stiffness and continuous or ordinal variables (Spearman’s correlation)

Variable	Statistical test result
Perceived effort	ρ = 0.6**
Playing-related disability [PAS-DASH]	ρ = 0.5**
Physical activity participation levels [IPAQ-SF]	ρ = 0.4**
Perceived health [SF-12] – Physical component	ρ = − 0.7**

*p < 0.05 

**p < 0.01

***p < 0.001

Spearman’s rank correlation (ρ) was used to assess correlations between mean muscle stiffness and continuous or ordinal variables

Table 5 reports Spearman’s rank correlation coefficients, revealing significant positive correlations between the mean MS and perceived effort (ρ = 0.6, p < 0.01), playing-related disability (PAS-DASH score; ρ = 0.5, p < 0.01), and physical activity level (IPAQ-SF score; ρ = 0.4, p < 0.01). In contrast, a strong negative correlation was found between the mean MS and the physical component of perceived health (SF-12; ρ = − 0.7, p < 0.01).

Table 6 presents group comparisons based on Mann–Whitney U tests. The participants who engaged in preparatory exercises and those who took breaks during practice sessions showed significantly lower mean MS values than their respective counterparts did (Z = − 2.1, p < 0.05; Z = − 2.8, p < 0.01, respectively).

Table 6.

Statistically significant differences in mean muscle stiffness across categorical variables

	Median (IQR)	Statistical test result
Preparatory exercises
Yes	327.4 (58.3)	𝑍 = −2.1*
No	348.4 (91.1)
Breaks
Yes	327.2 (51.4)	𝑍 = −2.8**
No	359.4 (74.0)

*p < 0.05

**p < 0.01

***p < 0.001

The Mann–Whitney U test was used for comparisons between two groups (Z). The median and interquartile ranges (IQRs) are reported

Discussion

This study provided insights into the relationships between MS, PRMDs, and other variables associated with playing a musical instrument. The first aim of this study was to determine whether MS in the UT differed between musicians with and without PRMDs. The participants were therefore divided into two distinct groups according to their condition and almost 47% self-reported a PRMD. This finding is in line with our previous work pertaining to the large-scale study population enrolled in several pan-European music universities, which reported a PRMD prevalence of 48% [45]. Nevertheless, no statistically significant difference was identified between the groups in terms of MS, and interestingly, the non-PRMD group presented a slightly higher mean value (352.4 N/m) compared to the PRMD group (335.7 N/m). Although this difference of 17 N/m was not statistically significant, it may still reflect a physiologically relevant variation. However, in the absence of established clinical thresholds or minimal clinically important differences for MS in musicians, its practical significance remains uncertain and future research to define such reference values is needed.

Unfortunately, the assessment of MS is limited among musicians, and its relationship with pain still warrants further exploration in this population. In our study, the results of the pain drawings revealed that the neck and shoulder regions were the most affected by PRMDs in both women and men, aligning once more with existing literature reporting pain in this area and therefore facing challenges while playing [3, 5–8]. However, our results indicated no significant relationships between MS and various pain parameters (i.e., pain extent, location, and intensity). This finding aligns with previous studies showing no clear connection between MS and pain. For instance, a study on chronic neck and back pain reported no association between pain intensity and increased myofascial stiffness [46]. Interestingly, some participants exhibited higher stiffness on the side with less pain, and interventions altering stiffness did not impact pain levels [46], suggesting that pain relief mechanisms may operate independently of modifications to tissue stiffness. Furthermore, a systematic review of musculoskeletal pain reported conflicting results, with some studies showing higher stiffness in symptomatic individuals, whereas others reported no difference or even lower stiffness in those with pain [47]. These discrepancies highlight the complexity of the relationship between MS and pain, suggesting that factors beyond MS may play a more pivotal role in pain perception and distribution, thereby underlining the multifactorial nature of pain.

Nevertheless, while MS was not directly linked to PRMDs, significant correlations were observed between mean MS and certain musician-related features, providing insights into its potential role in musculoskeletal health. A moderately strong positive correlation was found between perceived effort and MS, suggesting that individuals who experience greater exertion while playing tend to exhibit higher stiffness levels. Hildebrandt and colleagues [43] explored strategies for optimising musical practice and performance by improving the ergonomic aspects of playing. Focusing specifically on violinists, they evaluated muscle activation and perceived exertion while playing [42] and investigated individual position effects and biomechanical factors for compensatory movements of the left arm and shoulder. This highlights the potential for interventions targeting perceived effort to indirectly influence MS and related outcomes. In line with the latter, playing-related disability, as measured by the PAS-DASH, showed a significant positive correlation with MS. This finding suggests that musicians experiencing higher stiffness levels may be more likely to report functional impairments related to their instrument playing. Such disability can negatively impact performance quality and might potentially increase the risk of further musculoskeletal problems [8, 37]. The observed relationship highlights the importance of monitoring MS not only as a biomechanical parameter but also as a relevant factor linked to musicians’ functional health.

Similarly, the analysis of physical activity levels revealed significant correlations in MS across activity categories. Indeed, participants with low levels of physical activity presented the highest median stiffness scores, followed by those with high and moderate activity levels. This pattern highlights the nuanced relationship between physical activity and musculoskeletal health. For instance, Warburton and Bredin [48] systematically reviewed the health benefits of physical activity, emphasising the importance of balanced and appropriately dosed exercise regimens for optimising musculoskeletal and cardiovascular outcomes. Interestingly, while moderate physical activity appears protective, the literature also reports that variations in MS are associated with pain [9–11] and injury risk [16], underscoring the complex role of MS in musculoskeletal health beyond physical activity levels.

Similarly, the physical component score (PCS) of the SF-12 demonstrated a strong negative correlation with MS, emphasising its potential impact on physical health outcomes among musicians with pain. Indeed, the physical component median score for musicians with PRMDs was 47.2 (IQR 19.6), whereas it was 55.4 (IQR 6.4) for their counterparts without PRMDs. This finding suggests that musicians with PRMDs perceived relatively worse physical health, especially when a normative score of 50 for the PCS of the SF-12 was considered for the general population [33]. Similarly, the score referred to as the mental component score (MCS), despite not showing a statistically significant relationship with MS, was relatively low among both groups in comparison with normative data [33]. Musicians with PRMDs demonstrated a median MCS of 37.3 (IQR 14.1), which was substantially lower than the median of 44.8 (IQR 12.0) observed in those without PRMDs. This finding might reflect the broader psychological burden associated with PRMDs, including chronic pain, functional limitations, and stress related to professional performance. Additionally, the lower scores for both components for symptomatic musicians are consistent with previous research [49], highlighting the multifaceted impact of musculoskeletal disorders on physical and mental wellbeing [8, 50–52]. These findings reinforce the need for targeted interventions to address both the physical and psychological challenges associated with PRMDs, as well as a behavioural change towards health. Interventions aimed at reducing stiffness might contribute to increase musicians’ overall wellbeing and longevity. However, the causal dynamics between musculoskeletal pain, psychological distress, and changes in practice behaviour remain insufficiently understood, partly due to the scarcity of longitudinal evidence. It is conceivable that pain and psychological distress not only result from inadequate practice habits but may themselves drive behavioural adaptations over time, leading to muscular fatigue and maladaptive muscle activation patterns [51, 52]. In line with this, Stanhope and Weinstein [53] reported that musicians frequently perceive pain as influencing their approach to practice, highlighting a potentially dynamic and reciprocal relationship between physical symptoms, mental health, and preventive strategies. This complex interplay between pain, mood, resilience, and behavioural change warrants further investigation in future research.

In our study, practice habits (i.e., preparatory exercises and breaks during practice) were found to play a potential role in mitigating MS. Participants who engaged in preparatory exercises had significantly lower stiffness rates than those who did not. This finding aligns with existing evidence highlighting the benefits of warm-up routines in reducing muscle tension, enhancing flexibility, and improving muscle performance [54–57]. However, among musicians, the role of preparatory exercises has been less thoroughly explored. A study by McCrary et al. [58] examining skilled violinists found no significant changes in muscle activity or objective performance following a warm-up. However, participants reported a notable reduction in perceived exertion, suggesting that preparatory exercises may still provide important subjective benefits. Similarly, Cyganska et al. [59] demonstrated that both massage and exercise interventions had a positive effect on neck muscle tone, supporting the potential of physical strategies to modulate musculoskeletal properties and reduce strain in populations exposed to repetitive or static loading. These findings underscore the importance of structured warm-up routines not only for performance readiness, but also as a potential strategy for reducing the physical demands that contribute to MS, particularly in individuals engaged in repetitive motor tasks like music practice.

Breaks also emerged as a potentially significant factor related to MS. Individuals who reported taking breaks demonstrated significantly lower stiffness scores than those who did not. This result reinforces the necessity of integrating scheduled breaks into both occupational and educational contexts [60, 61] to mitigate the effects of sustained muscular activity on MS. This finding suggests that work-rest schedules, particularly in environments requiring repetitive tasks or prolonged static postures, might play a critical role in reducing muscular strain and improving overall performance. For instance, Lee et al. [62] found that female assembly line workers with myofascial trigger points exhibited significantly higher upper trapezius stiffness in the working posture (386.2 N/m) compared to asymptomatic individuals (335.2 N/m), with no difference in resting posture. The greater change in MS between working and resting postures in the symptomatic group highlights the influence of sustained task-related positions. These findings support the idea that occupation-specific demands, such as those encountered during music practice, can contribute to increased MS. Future research could focus on identifying which specific postures or playing techniques contribute most to increased MS, enhancing targeted prevention and intervention strategies for musicians.

Limitations

There are limitations to be aware of when considering the findings. Firstly, since this study involved a cross-sectional design, the findings cannot be considered conclusive, and no causal relationships can be established. Further prospective studies will help to corroborate the longitudinal patterning of these findings. Secondly, the sample of musicians was relatively small, especially the sub-sample of professional musicians (i.e., n = 11), thereby limiting the generalisability and statistical power of the analysis. Therefore, there is a need for replication within a homogeneous and broader range of music students and professional musicians. Accordingly, the heterogeneity of participants playing different musical instruments might have influenced the results and due to the restricted sample size, instrument-specific analyses were not statistically viable. Further studies involving large, instrument-specific populations would support meta-analytic integration and might contribute to a deeper understanding of the impact of biomechanical stress on the development of PRMDs.

Moreover, another limitation of the present study is that only the UT muscle was assessed, whereas multiple muscles and muscle groups are involved in musicians’ musculoskeletal health. Future studies should consider evaluating a broader range of muscles to provide a more comprehensive understanding.

In addition, potential confounding factors such as recent use of medications (e.g., anti-inflammatories, analgesics, antidepressants, or hormonal treatments) and pregnancy were not systematically assessed. The absence of this information may have influenced the measurements and should be addressed in future research through appropriate screening and standardised exclusion criteria. Furthermore, another limitation arises from the lack of standardisation in the assessment conditions. For example, some participants had recently engaged in intense practice sessions, whereas others had not been physically active for several hours. The variability in upper limb and UT muscle activity, including differences in duration and intensity, was beyond our control. Consequently, these factors might have influenced the results, introducing additional variability into the outcomes. Nonetheless, further studies involving a larger sample are needed, to examine whether the present findings could be reproducible across a broader range of music students and among professionals or similar populations.

Finally, the MyotonPRO device allows for the measurement of multiple mechanical properties, including muscle tone and elasticity, alongside stiffness. Although this study concentrated on stiffness as the primary outcome, future research should consider incorporating tone and elasticity measures to provide a more comprehensive understanding of muscle function in musicians. Nonetheless, given its ease of use, portability, and non-invasive nature, the MyotonPRO device may represent a promising tool for assessing MS and developing individual stiffness profiles in musicians. These profiles warrant further investigation through longitudinal designs, which could in turn inform the development of targeted preventive and treatment initiatives, thereby offering novel perspectives to the understanding of PRMDs.

Conclusions

Overall, the results suggest that MS was not directly associated with PRMDs but was significantly influenced by perceived effort, preparatory exercises, breaks, and physical activity levels, as well as playing-related disability and the physical component of perceived health. Since this study was the first to evaluate MS among musicians with and without PRMDs, further research should integrate biomechanical parameters to better understand the development of PRMDs in different instrumental groups. Future research should explore the longitudinal effects of these interventions and investigate the mechanisms underlying the observed relationships, contributing to a more comprehensive understanding of MS and its determinants.

Abbreviations

CSI

Conservatory of Southern Switzerland (Conservatorio della Svizzera italiana)

IPAQ-SF

International Physical Activity Questionnaire – Short Form

OSI

Orchestra della Svizzera italiana

MS

Muscle Stiffness

NRS

Numerical Rating Scale

PAS –DASH

Performing Arts Section of the Disabilities of the Arm, Shoulder, and Hand Outcome Measure

PRMDs

Playing-related musculoskeletal disorders

SF-12

12-Item Short Form Health Survey

SYP

Sketch Your Pain software

UT

Upper Trapezius

Authors’ contributions

All authors made substantial contributions to the work presented in this manuscript. CC, PS, and MB conceived and designed the study. CC coordinated the research activities, oversaw the project, contributed to the interpretation of the findings, and drafted the manuscript. CC and PS conducted data collection. AS and SV supervised the methodological framework. MB provided overall supervision of the project. All authors contributed to the review and revision of the manuscript, discussed the results and study procedures, and approved the final version.

Funding

The authors declare that they have no funding.

Data availability

The data supporting this study are available upon request from the corresponding author.

Declarations

Ethics approval and consent to participate

All procedures performed in this study were in accordance with the ethical standards of the Cantonal Research Ethics Committee of Canton Ticino (Switzerland) (Ref. CE 4447, BASEC 2023 − 01616) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Additionally, the study reporting adheres to the STROBE guidelines for observational studies.

Before starting any procedure, all participants received written information about the study and signed an informed consent.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.