Region-specific prevalence and associated factors of work-related musculoskeletal disorders among pilots of a commercial airline: a cross-sectional study

Abstract

Objectives

To estimate the prevalence and anatomical distribution of work-related musculoskeletal disorders (WMSDs) among pilots of a Chinese commercial airline and identify factors associated with neck, shoulder and lower-back WMSDs.

Design

Cross-sectional study.

Setting

A commercial airline in China; data were collected during routine periodic medical examinations from 17 November 2025 to 31 December 2025.

Participants

A total of 1042 active commercial airline pilots (1030 men and 12 women) were included from 1200 invited pilots.

Primary and secondary outcome measures

The prevalence of WMSDs across nine anatomical regions and factors associated with WMSDs in the neck, shoulders and lower back.

Results

The overall prevalence of WMSDs was 21.50%; the most commonly affected regions were the lower back (11.52%), neck (11.32%) and shoulders (8.35%). Working in uncomfortable postures was associated with WMSDs across all three regions, particularly for ‘often’ exposure: neck (adjusted OR (aOR) 7.97, 95% CI 3.58 to 17.76), shoulders (aOR 5.48, 95% CI 2.35 to 12.80) and lower back (aOR 8.58, 95% CI 3.89 to 18.94). Neck WMSDs were associated with prolonged head-down posture and covering shifts for colleagues, whereas adequate rest time was inversely associated. Shoulder WMSDs were associated with prolonged static back posture. Lower-back WMSDs were positively associated with covering shifts and cold/temperature exposure and inversely associated with adequate rest, daily task variation and outdoor work.

Conclusions

WMSDs most commonly affected the lower back, neck and shoulders. Working in uncomfortable postures was consistently associated with WMSDs across these regions, while work-organisation and environmental factors showed site-specific associations.

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• A large analytic sample (n=1042) was obtained through consecutive recruitment, with a questionnaire response rate of 93.6%.

• The questionnaire was adapted from the standardised Nordic Musculoskeletal Questionnaire and Dutch Musculoskeletal Questionnaire, facilitating comparison with previous occupational health research.

• Multivariable logistic regression analyses, performed separately for the neck, shoulders and lower back, adjusted for potential confounders.

• The cross-sectional design precludes causal inference.

• Recruitment of pilots from a single airline may limit generalisability; the healthy worker effect may have led to underestimation of work-related musculoskeletal disorders prevalence.

Introduction

Musculoskeletal disorders are a major occupational and public health problem and an important contributor to disability and impaired work ability.¹ Work-related musculoskeletal disorders (WMSDs) refer to musculoskeletal conditions that are attributable to the work environment and the performance of work tasks.² WMSDs are multifactorial, with biomechanical exposures such as awkward or sustained postures and repetitive work acting in combination with psychosocial, work-organisational and individual factors.^{3 4}

In China, national occupational studies have documented substantial WMSDs burdens in key industries, including civil aviation-related workers,^{5 6} but evidence specifically concerning commercial airline pilots remains limited. Commercial airline pilots have distinctive exposures, including prolonged constrained sitting, sustained neck, shoulder and spinal loading, limited opportunities for movement, irregular schedules, fatigue and high mental workload. International studies among commercial airline pilots have reported substantial musculoskeletal symptom burdens, particularly in the lower back, neck and shoulders, with occupational correlates including constrained postures, physical workload, turbulence, flying hours, cockpit seat comfort, work demands and rest opportunities.^7–11

However, most studies have focused on low back pain rather than WMSDs across multiple anatomical regions, and few have examined whether associated factors differ by body region. Evidence from Chinese military pilots is not directly generalisable because exposures such as high G-forces, helmet-related loading and intensive flight training differ substantially from commercial aviation.^{12 13}

To address these gaps, this cross-sectional study aimed to estimate the prevalence and anatomical distribution of WMSDs among pilots of a Chinese commercial airline and to identify demographic, ergonomic, occupational and work-organisational factors associated with WMSDs in the most commonly affected body regions.

Methods

Study design and data collection

This study employed a cross-sectional design. Data were collected using a self-administered electronic questionnaire. The questionnaire employed was the Chinese Version of the Musculoskeletal Disorders Questionnaire, provided by the Chinese Center for Disease Control and Prevention. This instrument was originally adapted from the Nordic Musculoskeletal Questionnaire¹⁴ and the Dutch Musculoskeletal Questionnaire.¹⁵ It was previously validated and demonstrated good reliability and validity for use among Chinese occupational populations.^16–18 The questionnaire was administered by trained investigators who explained the study objectives and instructions for completion to each participant. Participants completed the questionnaire independently on site and submitted their responses electronically.

Sample size calculation and participants

Active commercial airline pilots were consecutively recruited from a domestic airline in China during routine periodic medical examinations, with data collected from 17 November 2025 to 31 December 2025. All active commercial airline pilots presenting for routine periodic medical examinations during the recruitment period were invited to participate. Returned questionnaires were subsequently screened for eligibility and data quality. Of 1200 invited pilots, 1123 returned the questionnaire (response rate, 93.6%). After removing duplicate records (n=2), 1121 unique records were screened. 79 questionnaires were excluded because of invalid responses, including implausible anthropometric values, pre-existing musculoskeletal conditions or trauma history, logically inconsistent flight-hour data or other data quality concerns. Finally, 1042 valid questionnaires were retained for analysis, representing 86.8% of all invited pilots. The participant recruitment, exclusion and inclusion process is summarised in figure 1.

Figure 1. Flow diagram of participant recruitment, screening, and inclusion.

Participants were eligible if they met the following criteria: (i) age ≥18 years; (ii) flight experience ≥1 year; and (iii) no history of congenital musculoskeletal disorders, traumatic injuries, rheumatoid arthritis or other conditions potentially affecting the musculoskeletal system. The exclusion criteria were as follows: (i) involvement in a flight accident or severe trauma within the preceding 6 months; and (ii) musculoskeletal symptoms attributable to other diagnosed medical conditions.

The sample size was estimated using the single-proportion formula for cross-sectional studies:

$${\displaystyle {\displaystyle n=Z_{\alpha /2}^{2}p(1-p)/d^2}}$$

Because data on WMSDs among Chinese commercial airline pilots were limited, the 71.3% prevalence of low back pain reported among Saudi Arabian commercial airline pilots¹¹ was used as a proxy reference estimate for sample size estimation. Low back pain was selected because it was the most consistently reported musculoskeletal outcome among commercial airline pilots in the available literature.^7–11 An absolute precision of 3 percentage points was prespecified to provide a reasonably precise prevalence estimate while maintaining feasibility within the available pilot population; this corresponds to a 95% CI with a half-width of approximately 3 percentage points around the expected prevalence. With a 95% confidence level, an expected prevalence of 71.3%, and an absolute precision of 3%, the minimum required number of valid responses was estimated to be approximately 874. To allow for potential non-response and invalid questionnaires, 1200 pilots were invited to participate.

Measures

Data were collected on demographic and occupational variables, including sex, age, height, weight, educational level, flight experience (years), cumulative flight hours, smoking history and physical exercise habits. The occurrence of musculoskeletal discomfort during the preceding 12 months was assessed across nine anatomical regions—neck, shoulders, upper back, lower back, elbows, hands/wrists, hips/thighs, knees and feet/ankles—together with the frequency and duration of symptoms. Diagnostic criteria for WMSDs were adapted from the standard definition of the National Institute for Occupational Safety and Health.^19–21 A region-specific WMSD case was defined as the co-occurrence of all of the following conditions: (i) discomfort in that region during the past 12 months; (ii) symptom onset after commencing the current occupation; (iii) no prior acute injury or accident affecting the symptomatic region; and (iv) symptoms occurring at least once per month or lasting longer than 1 week.

Quality control

Prior to survey implementation, the study objectives were clearly defined, and a detailed investigation protocol was developed during the initial design phase. All investigators—specifically aviation physicians employed by the participating airline—received standardised training covering the study objectives, significance, background and specific procedures for data collection and quality assurance to ensure consistency and accuracy in questionnaire administration. During the survey, a one-to-multiple (1:N) approach was adopted, whereby a single trained investigator provided face-to-face instructions to a group of participants who independently completed the questionnaire by scanning a QR code using their mobile devices and submitting responses online. On submission, data were uploaded directly to a secure cloud server, thereby ensuring the authenticity and integrity of the collected information. The electronic questionnaire incorporated built-in logic validation and completeness verification functions to minimise implausible entries and missing responses. Completion progress was monitored in real time via a back-end management system, helping to minimise incomplete or invalid submissions. Following data collection, all completed questionnaires were downloaded immediately and manually reviewed for implausible entries, which were subsequently excluded from the analysis.

Statistical analysis

All analyses were performed using R V.4.4.2. There were no missing values for any variables included in the final analyses; therefore, no imputation was performed. Continuous variables are presented as mean±SD or median (IQR), depending on the normality of their distribution. Categorical variables are summarised as frequencies (percentages). Continuous variables in the univariable analyses were compared using the Mann-Whitney U test. Categorical between-group comparisons were performed using the χ² test or Fisher’s exact test, as appropriate. For regression analyses, cumulative total flight hours were scaled in units of 1000 hours. Variables showing statistical significance (p<0.05) in univariable analyses were entered into body-region-specific multivariable logistic regression models for WMSDs in the neck, shoulders and lower back. Sex, age and total flight hours were forced into all models regardless of their univariable significance. Multicollinearity was assessed using variance inflation factors (VIFs) and generalised variance inflation factors, as appropriate. VIFs for age and total flight hours ranged from approximately 5.0–6.1 across the three models, whereas values for the remaining covariates were substantially lower. The complete lists of variables entered into each initial model are provided in online supplemental table S3, and the full model outputs are available in online supplemental table S4. All tests were two-sided, with statistical significance set at α=0.05.

Results

Basic characteristics of participants

A total of 1042 valid questionnaires were included in the final analysis, comprising 1030 men and 12 women and representing 86.8% of all invited pilots. Participant sociodemographic and work-related characteristics are summarised in table 1. The median age was 33 years (IQR: 30–36 years). Overall, 365 pilots (35.03%) were captains and 677 (64.97%) were first officers.

Table 1. Sociodemographic and work-related characteristics of participating commercial airline pilots.

Item	n	%
Sex
Male	1030	98.85
Female	12	1.15
Position
First officer	677	64.97
Captain	365	35.03
Age (years)
<25	3	0.29
25–34	689	66.12
35–44	310	29.75
≥45	40	3.84
Flight experience (years)
<2	36	3.45
2–3	134	12.86
4–5	200	19.19
6–7	155	14.88
≥8	517	49.62
Body mass index (kg/m²)
<18.5	7	0.67
18.5–23.9	554	53.17
≥24.0	481	46.16
Education level
College diploma or below	7	0.68
Bachelor’s degree	979	93.95
Master’s degree or above	56	5.37
Smoking status
Never	808	77.54
Occasionally	148	14.20
Frequently	28	2.69
Quit smoking	58	5.57
Physical exercise
Never	30	2.88
Occasionally	297	28.50
2–3 times per month	125	12.00
1–2 times per week	345	33.11
>Twice a week	245	23.51
Total flight hours (hours)
<1500	195	18.71
1500–3000	258	24.76
3001–10 000	415	39.83
>10 000	174	16.70

BMI categories were based on the Chinese adult standard (WS/T 428-2013): normal weight, 18.5≤BMI<24.0 kg/m²; overweight or obesity, BMI≥24.0 kg/m². Percentages may not total 100% due to rounding.

Prevalence of WMSDs by anatomical site

The overall prevalence of WMSDs, defined as the presence of WMSD symptoms in at least one of the nine anatomical regions assessed, was 21.50% (224/1042) among the participating pilots. By anatomical site, the highest prevalence was observed in the lower back (n=120, 11.52%), followed by the neck (n=118, 11.32%) and shoulders (n=87, 8.35%). The lowest prevalence was observed for the elbows and hands/wrists, both at 0.58% (n=6 each). The overall prevalence and anatomical-region-specific distribution of WMSDs are presented in figure 2.

Figure 2. The prevalence of work-related musculoskeletal disorders by anatomical region among commercial airline pilots.

Univariable comparisons of WMSD prevalence across subgroups

Online supplemental table S1 presents univariable comparisons of the prevalence of WMSDs in the lower back, neck, and shoulders across subgroups defined by demographic characteristics, lifestyle factors, task types, work-organisation patterns and work-related postural factors. Most sociodemographic and occupational seniority variables, including professional rank, age, flight experience, body mass index, education level, marital status and total flight hours, showed no significant differences in WMSDs prevalence across subgroups for any of the three anatomical regions. In contrast, significant subgroup differences were mainly observed for work-related postural and organisational factors, including prolonged sitting, uncomfortable working posture, repetitive tasks, same daily work routine, frequent overtime work, insufficient break time, staff shortage, covering shifts for colleagues, prolonged static back or neck posture and prolonged head-down posture. Results for continuous variables are summarised in online supplemental table S2.

Multivariable analysis of factors associated with WMSDs

Variables showing statistical significance (p<0.05) in the univariable analyses (online supplemental tables S1 and S2), together with sex, age and total flight hours, were considered for inclusion in the multivariable logistic regression models. Separate multivariable logistic regression models were constructed for WMSDs in the neck, shoulders and lower back. For readability, table 2 presents variables that remained statistically significant in at least one body-region-specific model, whereas the complete outputs of the initial models are provided in online supplemental table S4.

Table 2. Multivariable logistic regression analysis of factors associated with neck, shoulder and lower-back WMSDs among 1042 commercial airline pilots.

Variable	aOR (95% CI)
	Neck WMSDs	Shoulder WMSDs	Lower-back WMSDs
Sex
Male		1.00 (ref.)
Female		9.54 (1.83 to 49.77)*
Uncomfortable working posture
Rarely/never	1.00 (ref.)	1.00 (ref.)	1.00 (ref.)
Sometimes	2.90 (1.61 to 5.25)*	2.26 (1.20 to 4.27)*	2.47 (1.41 to 4.32)*
Often	7.97 (3.58 to 17.76)*	5.48 (2.35 to 12.80)*	8.58 (3.89 to 18.94)*
Very frequently	2.37 (0.71 to 7.87)	1.75 (0.49 to 6.23)	4.68 (1.44 to 15.20)*
Frequency of repetitive operations during work
Rarely/never			1.00 (ref.)
Sometimes			0.82 (0.48 to 1.41)
Often			0.43 (0.19 to 0.98)*
Very frequently			0.47 (0.17 to 1.28)
Often turn around while working
No	1.00 (ref.)
Yes	2.31 (1.04 to 5.15)*
Prolonged static back posture
No		1.00 (ref.)
Yes		2.67 (1.19 to 5.99)*
Prolonged head-down posture
No	1.00 (ref.)
Yes	3.23 (1.80 to 5.80)*
Adequate rest time
No	1.00 (ref.)		1.00 (ref.)
Yes	0.51 (0.30 to 0.86)*		0.48 (0.29 to 0.81)*
Covering shifts for colleagues
No	1.00 (ref.)		1.00 (ref.)
Yes	2.83 (1.50 to 5.34)*		2.22 (1.15 to 4.26)*
Daily variation in job tasks
No			1.00 (ref.)
Yes			0.41 (0.20 to 0.85)*
Work performed outdoors
No			1.00 (ref.)
Yes			0.21 (0.08 to 0.56)*
Exposure to cold drafts or temperature fluctuations
No			1.00 (ref.)
Yes			2.99 (1.59 to 5.61)*

Only variables with at least one statistically significant category (p<0.05) in a body-region-specific model are shown; all category levels of included variables are reported. Sex, age and total flight hours were forced into all models regardless of their univariable statistical significance. Complete outputs of the multivariable models are provided in online supplemental table S4. *p<0.05.

aOR, adjusted OR; WMSDs, work-related musculoskeletal disorders.

In the multivariable models, working in uncomfortable postures was the only factor consistently associated with WMSDs across all three anatomical regions. Compared with pilots who rarely or never worked in uncomfortable postures, those reporting ‘sometimes’ or ‘often’ exposure had significantly higher odds of neck, shoulder and lower-back WMSDs. The strongest associations were observed for ‘often’ exposure, with adjusted ORs (aORs) of 7.97 (95% CI 3.58 to 17.76) for neck WMSDs, 5.48 (95% CI 2.35 to 12.80) for shoulder WMSDs and 8.58 (95% CI 3.89 to 18.94) for lower-back WMSDs. ‘Very frequent’ exposure was significantly associated only with lower-back WMSDs (aOR 4.68, 95% CI 1.44 to 15.20).

Several region-specific associations were also observed. Neck WMSDs were positively associated with prolonged head-down posture and covering shifts for colleagues, and often turning around while working, whereas adequate rest time was inversely associated with neck WMSDs. Shoulder WMSDs were additionally associated with prolonged static back posture; female sex was also associated with shoulder WMSDs, although the estimate was imprecise because only 12 women were included. For lower-back WMSDs, covering shifts for colleagues and exposure to cold drafts or abrupt temperature fluctuations were positively associated with WMSDs, whereas adequate rest time, daily variation in job tasks and outdoor work were inversely associated with lower-back WMSDs. The ‘often’ category for frequency of repetitive operations during work was also associated with lower odds of lower-back WMSDs (aOR 0.43, 95% CI 0.19 to 0.98), although no consistent exposure-response pattern was observed across exposure categories.

Discussion

This cross-sectional study investigated the prevalence, anatomical distribution and associated factors of WMSDs among 1042 commercial airline pilots from a Chinese commercial airline. The overall prevalence of WMSDs was 21.50%, with the lower back, neck and shoulders being the most commonly affected regions. Multivariable analysis showed that uncomfortable working posture was consistently associated with WMSDs across all three regions. In addition, region-specific associations were observed, involving prolonged head-down posture, prolonged static back posture, covering shifts for colleagues, cold drafts or temperature fluctuations, adequate rest time, daily variation in job tasks and outdoor work.

The overall prevalence observed in the present study was lower than that reported in several previous studies of commercial airline pilots, particularly studies focusing on low back pain. Studies from Thailand,⁷ Colombia,⁹ Germany¹⁰ and Saudi Arabia¹¹ have reported substantially higher prevalences of low back pain among commercial airline pilots, whereas a Swedish study⁸ examining multiple body regions found that low back, shoulder and neck symptoms were among the most common musculoskeletal complaints. The lower prevalence observed in our study may partly reflect methodological differences from previous pilot studies. Our WMSDs definition required recurrent or persistent symptoms with an occupational temporal relationship and excluded prior acute injury, whereas previous studies generally used broader symptom-based definitions. Differences in age, cumulative flight exposure and recruitment methods may also have contributed. In addition, the healthy worker effect may have contributed to the relatively low prevalence observed in this study. Because only active pilots undergoing routine periodic medical examinations were recruited, pilots with more severe musculoskeletal disorders who were unable to maintain active flying duties may have been underrepresented, potentially leading to an underestimation of the true WMSDs burden. Therefore, these findings should not be interpreted as evidence that the underlying musculoskeletal burden is genuinely lower in this population.

Working in uncomfortable postures was the only factor consistently associated with WMSDs in all three commonly affected regions. This finding is consistent with ergonomic evidence showing that awkward or static postures, repetitive movements, vibration and prolonged task duration may contribute to WMSDs.^{3 4} In commercial pilots, prolonged sitting, limited opportunities for movement and cockpit seat comfort have also been highlighted as relevant occupational factors.^{8 11}

The association between prolonged head-down posture and neck WMSDs is plausible because cockpit tasks, instrument monitoring, checklist use and communication may require sustained cervical flexion. Previous studies have shown that neck symptoms are common among pilots. A Swedish study⁸ of commercial pilots reported a high prevalence of neck symptoms, while a study¹² of Chinese fighter pilots reported a high prevalence of occupational neck pain and identified continuous flight training and coexisting shoulder and low back pain as related factors.

Shoulder WMSDs were associated with prolonged static back posture, suggesting that sustained spinal and scapular loading may contribute to shoulder symptoms. This is consistent with evidence that shoulder and neck symptoms in occupational groups may be influenced by both biomechanical and psychosocial factors,⁴ and with findings among Swedish commercial pilots showing that shoulder symptoms were common and associated with high work demands and low social support.⁸ Female sex was also associated with shoulder WMSDs in the multivariable model; however, this estimate was based on only 12 female pilots and had a wide CI, so it should be interpreted cautiously as an imprecise association rather than evidence of a sex-specific effect.

For lower-back WMSDs, the associations with uncomfortable posture, covering shifts and cold drafts or temperature fluctuations may reflect the combined effects of static sitting, cumulative workload, environmental discomfort and insufficient recovery. Previous studies among commercial airline pilots have also identified flight-related and ergonomic factors, such as turbulence, luggage lifting, perceived work hazards, physical load, work time, flying hours and cockpit seat comfort, as relevant to low back pain.^{7 9–11} The inverse association observed only for the ‘often’ category of frequency of repetitive operations during work should be interpreted cautiously because no consistent exposure-response pattern was observed across categories.

The findings related to adequate rest time, covering shifts for colleagues and daily variation in job tasks highlight the importance of work organisation. Previous research among commercial airline pilots has suggested that psychosocial work conditions and rest breaks are relevant to musculoskeletal symptoms.^{7 8} Large-scale occupational studies in China have also shown that work-organisation factors, including overtime work, staff shortages, rest time and job rotation or task variation, are associated with WMSDs in occupational populations.^{5 6} These findings support further prospective evaluation of scheduling optimisation, adequate recovery time and workload management as potential intervention targets rather than establishing preventive effects.

In China, previous research has provided evidence on WMSDs among key occupational groups and civil aviation-related workers including flight attendants.^{5 6} Studies among Chinese military pilots have also reported a high burden of neck pain and low back pain.^{12 13} However, flight attendants and military pilots differ substantially from commercial airline pilots in ergonomic exposure, aircraft tasks, training intensity and work organisation. Therefore, the present study provides population-specific evidence for Chinese commercial airline pilots.

Several potential areas for preventive intervention may represent potential targets. The consistent association between uncomfortable working posture and WMSDs across the neck, shoulders and lower back suggests that cockpit ergonomic optimisation should be a shared priority across anatomical regions. Potential measures may include improving seat support and adjustability, optimising instrument panel layout and reducing sustained head-down postures where feasible. Ensuring adequate rest time and limiting shift coverage are also reflected by the inverse association with adequate rest and the independent positive association with covering shifts. Task diversification, where operationally feasible, may represent another potential target for prospective evaluation. In addition, the association between cold drafts or abrupt temperature fluctuations and lower-back WMSDs suggests that cockpit microclimate management, including airflow direction and temperature control, should be considered. These findings identify ergonomic, organisational and environmental factors that warrant prospective evaluation as potential targets for WMSD prevention among commercial airline pilots.

However, several limitations should also be acknowledged. First, the cross-sectional design precludes causal inference and does not allow the temporal sequence between occupational exposures and WMSDs to be established. Second, recruitment from a single Chinese commercial airline may limit generalisability. Although female pilots were retained in the analysis, their small number (n=12) resulted in imprecise sex-specific estimates and limits the interpretation and generalisability of findings for female pilots. Third, all data were self-reported and may therefore be subject to recall and reporting bias; in addition, WMSDs were not clinically diagnosed, and objective ergonomic measurements were not available. The healthy worker effect may also have resulted in underestimation of WMSD prevalence because the study included only active commercial airline pilots. Fourth, psychosocial factors such as job stress, fatigue and social support, which may contribute to musculoskeletal disorders, were not assessed and may have confounded some of the observed associations. Future studies would benefit from prospective designs, objective exposure measurements, clinical assessment of WMSDs and the inclusion of psychosocial variables to provide a more comprehensive understanding of the aetiology of WMSDs in this occupational group.

Conclusions

This study assessed the prevalence, anatomical distribution and site-specific correlates of WMSDs among Chinese commercial airline pilots. Uncomfortable working posture was consistently associated with WMSDs across the neck, shoulders and lower back, while adequate rest time was inversely associated with WMSDs in multiple regions. The findings highlight the multifactorial nature of WMSDs in this occupational group, encompassing ergonomic, environmental and work-organisational dimensions. These results may inform the development of targeted prevention and occupational health management strategies for commercial airline pilots.

Data availability statement

Data are available upon reasonable request.