Job satisfaction among aircraft baggage handlers and their exposure to risk factors for work-related musculoskeletal disorders: A case study

Abstract

BACKGROUND: Work-related musculoskeletal disorders (WMSDs) cause pain and economic loss. Risk of WMSDs is affected by job satisfaction as a psychosocial factor.

OBJECTIVE: The aim of this study was to investigate job satisfaction among aircraft baggage handlers and their exposure to work-related musculoskeletal disorder risk factors.

METHODS: Two data collection tools addressing risk levels (Quick Exposure Check) and psychosocial factors (Job Satisfaction Survey) were answered by 399 male baggage handlers employed in Esenboga International Airport in Ankara, Turkey.

RESULTS: Risk exposure scores for WMSDs among baggage handlers were 27±3.4 (high) for the back (static), 42±7.2 (very high) for the back (moving), 42±6.1 (very high) for the shoulder/arm, 44±1.9 (very high) for the wrist/hand, and 13±5.1(high) for the neck. The average job satisfaction levels of the majority was either low (4.2250±1.10184) or moderate (3.1019±0.93352). In addition, low and moderate job satisfaction was significantly associated with higher WMSD risk levels among baggage handlers.

CONCLUSIONS: Increased WMSD risk levels among baggage handlers are associated with low and moderate job satisfaction, suggesting that it is mandatory to perform intervention methods in this occupation.

Keywords

Baggage handlers musculoskeletal disorders job satisfaction quick exposure check

1 Introduction

Work-related musculoskeletal disorders (WMSDs) include a wide range of inflammatoryand degenerative conditions affecting the muscles, tendons, joints, peripheral nerves and supporting blood vessels. Body parts most commonly involved are the back, neck, shoulder, upper and lower extremities. WMSDs are widespread and costly, causing great personal and socio-economic effects in many countries.

WMSDs occur in certain occupations with rates up to three of four times higher than the overall frequency. High risk sectors include air transportation, nursing facilities, food processing, mining, heavy and light manufacturing [1 –3]. Besides physical risk factors, work-related psychosocial factors such as time pressure, low job control, low job satisfaction, lack of social support at work and perceived high work stress have been identified as predictors for WMSDs [4].Over the last 20 years, WMSDs have attracted increasing interest from ergonomists, employers, and health and safety practitioners. WMSDs are considered to be a major cause of disability, absence from work and requests for health care [5].

The global airline industry continues to grow rapidly. To illustrate, it doubled from US$369 billion in 2004 to $746 billion in 2014, according to the International Air Transport Association (IATA) [6].

Baggage handling work performance is an important part of the civil aviation flight cycle. Baggage handlers’ job tasks vary depending on flight schedules, types of aircrafts and types of servicesections [7].

Posture-related changes may occur due to changes in the muscle moment arm, alteration of muscle length, reduced number of muscles in hips and thighs contributing to the lifting moment and decreased stability and mobility while kneeling. Two common workplace parameters, baggage weight and lift destination height, affect the biomechanical loading of the spine while in kneeling postures. It was found that kneeling resulted in lower activity of trapezius muscle, increased spinal compressions and spine anterior-posterior shear. It is known that kneeling is a more limited posture than standing. Spine loading is significantly affected by destination, height and load weight when handling manual materials in a kneeling posture. Lower ceiling height increases spinal compression in a simulation of baggage handling and results in increased sagittal moment [8, 9]. Reddell et al. [10] evaluated the relationship between weightlifting belts and prevention from back injury among 642 airline baggage handlers working for a major airline company. They found that the use of weightlifting belts could not be recommended for baggage handlers as the use of belts increased the risk of injury, especially when not wearing a belt following a period of wearing one. Riley [11] suggested that a baggage weight limit between 23 to 25 kg is a step that would have a positive effect in reducing the risk of handling-related injuries. However, such a measure may not have an overall effect on the average weight of items handled. Oxley et al. [12] conducted a study on baggage handlers from United Kingdom airports and reported 73% trouble in the lower back, 51% in the knees and 43% in the shoulders during the previous 3 months. These results showed that baggage handling staff were often exposed to a high level of risk during the routine manual pushing and pulling of the baggage.

In another study, musculoskeletal symptoms and chronic effects from cumulated workload in Danish airport baggage handlers were examined. It was found that musculoskeletal symptoms in the neck, upper back, lower back, shoulders, elbows, wrists, hips and knees were significantly higher than in a reference group of men from other unskilled occupations with less heavy work. Cumulated heavy lifting in awkward positions did not affect only lower back, knees and shoulders, but also other anatomical regions such as the wrists and elbows [13]. In a recent study, musculoskeletal disorders and psychosocial factors were investigated among 525 Swedish flight baggage handlers in six Swedish airports. The Standardized Nordic Questionnaire and Copenhagen Psychosocial Questionnaire were used as tools to assess WMSDs and psychosocial factors. According to the study, lower back and shoulder pain was reported 70% and 60%, respectively. Lower back pain with perceived disability was shown to be significantly related to awkward and extreme arm postures while baggage handling in narrow aircraft compartments. This study also revealed associations between psychosocial factors and WMSDs [14].

WMSDs among aircraft baggage handlers might be explained primarily by physical load associated with their job tasks, including frequently pushing or pulling heavy baggages and lifting or carrying heavy objects [15]. Injuries resulting from manual handling tasks represent an ongoing problem for the transport and storage industry worldwide. Internationally, a survey of baggage handlers revealed that 46% had suffered a back injury while at work. This suggests that approaches currently employed in this industry are insufficient to teach safety factors during manual handling [16].

Many researchers have argued that job satisfaction is key for job performance and service recovery. Previous studies showed that the depletion or scarcity of organizational resources, coupled with constant or even increased performance expectations, may have drastic effects on employee psychology. High level of exhaustion makes cargo handlers perceive themselves as less capable of handling their job, therefore resulting in low job satisfaction [17].

Ergonomics (human factors) is the scientific discipline concerned with the understanding of the interactions among humans and other elements of a system, and the profession that applies theoretical principles, data and methods to design in order to optimize well-being and overall performance. Practitioners of ergonomics contribute to the planning, design, implementation, evaluation, redesign and continuous improvement of tasks, jobs, products, technologies, processes, organisations, environments and systems in order to make them compatible with the needs, abilities and limitations of people [18].

The present study aimed to investigate the job satisfaction levels and WMSD risk factors of aircraft baggage handlers. This is the first study evaluating job satisfaction and exposure to risk factors for work-related musculoskeletal disorders among aircraft baggage handlers in Turkey. The results of the study will inform practitioners engaged in planning appropriate ergonomics for baggage handlers in Ankara, Turkey.

2 Methods

2.1 Workplace characteristics

Turkish Airlines is the national airline of Turkey which operates flights in 37 Turkish airports and around 130 foreign destinations worldwide. Its main hub is located in Atatürk International Airport of Istanbul. Turkish Airlines transports over 25 million passengers every year. As of the end of 2013, a total of 3,966 people (1,800 cabin personnel, 993 cockpit personnel, 1,173 ground personnel) were employed at Turkish Airlines. Ground handling services for the airline are provided by Turkish Ground Services (TGS), a joint venture. In Esenboga International Airport in Ankara, Turkey, TGS has 543 employees involved in various activities and functions associated with the operation, development and maintenance of the airport facility [19]. The safe and timely processing of arrival and transfer of baggage is the responsibility of Ramp Service Staff.

2.2 Participants

Baggage handling is characterised by repeated work tasks consisting of loading and unloading baggage, air express and air cargo shipments. The staff operate baggage tugs, conveyors, fork lifts and other baggage and air freight handling equipment.

Baggage handlers use forklifts, baggage carts and conveyors to load aircrafts in a safe and cautious manner. These materials are loaded in the baggage compartments of aircrafts. The handlers have no freedom to determine their work schedules. They work on arriving and departing aircrafts, which provides them with a varied work plan depending on airline schedules. Baggage handlers work shifts between 8 and 11 hours per day, with 6 days on and 1 day off, in all weather conditions including extreme weather. They receive periodic pay rises based on seniority and experience. An average airline baggage weighs about 25–30 kilograms and handlers load about 150–200 bags for each flight. Most of the lifts are performed in awkward positions: stooped, squatting, sitting and kneeling.

The participants in this study were recruited via contact lists of TGS and invited to take part in this study. A total of 399 Turkish baggage handlers were employed for ramp service in Esenboga International Airport. All handlers were 18 years or older, and had either finished high school or attended university. Baggage handlers were informed as to the purpose of the study and they completed the surveys on a voluntary basis in approximately 20–25 minutes during their work times. All the baggage handlers were male, aged between 22 to 51 and above. In the questionnaire the participants were asked about their age, gender and work experience in years.

2.3 Procedures

In order to consider the information on musculoskeletal symptoms and job satisfaction, Quick Exposure Check (QEC) and Job Satisfaction Survey (JSS) were used.

2.3.1 QEC

QEC was developed by Li and Buckle in 1998 and modified by David, Woods and Buckle in 2003. Evaluation of the inter-user reliability, validity and usability of QEC were determined in two phases, with the participation of 206 practitioners. The reliability coefficients of QEC items were found to vary between 0.589 and 1 [20]. QEC assesses four areas of the body, namely the back, shoulder/arm, wrist/hand and neck, with regard to postures and repetitive movements. A combination of different risk factor exposures is shown in Table 2. The exposure levels for back, shoulder/arm, wrist/hand and neck are categorised into four exposure categories: low, moderate, high and very high.

For the back (static), a score between 8 and 15 denotes low risk, one between 16 and 22 denotes moderate risk, 23 and 29 denotes high risk, and 29 and 30 denotes very high risk. For the back (moving),shoulder/arm and wrist/hand, a score between 10 and 20 suggests low risk, one between 21 and 30 suggests moderate risk, 31 and 40 suggests high risk, and 41 and 60 suggests very high risk. For the neck, a score between 4 and 6 indicates low risk, one between 8 and 10 indicates moderate risk, 12 and 14 indicates high risk, and 16 and 20 indicates very high risk. The reliability of the Turkish translation of the QEC was investigated by Özcan et al. who concluded it to be a useful and sensitive observational technique for assessing exposure to risk factors forWMSDs [21].

2.3.2 JSS

The term job satisfaction refers to individuals’ attitudes towards their jobs, status, wages, working conditions and changes in goals. The job satisfaction of baggage handlers was assessed by using the JSS, a frequently used job satisfaction instrument developed by Paul Spector. He describes job satisfaction as “the extent to which people like (satisfaction) or dislike (dissatisfaction) their jobs”. JSS includes 36 items and nine subscales. Each subscale is assessed with four items and a total score is computed from all items. The rating scale format includes six choices per item changing from “strongly disagree” to “strongly agree”. The nine subscales are pay, promotion, supervision, fringe benefits, performance based rewards, operating procedures, coworkers, nature of work and communication. Total job satisfaction scores based on the sum of all 36 items range between 36 and 216. High scores represent job satisfaction. The validity and reliability of Turkish Version of the JSS was assessed by Yelboga who reported that JSS is a valid and reliable instrument that may be used to measure job satisfaction. The reliability estimate for the total scale is 0.78 for the thirty-six items of the adopted scale [22, 23].

2.4 Data collection

Direct contact was established between the researchers and baggage handlers with the permission of the Executive Board of the Esenboga International Airport and the Union of Ground Service Staff. Possible questions about socioeconomic status of the baggage handlers were not included as this information was considered sensitive and might violate their privacy. The participants were asked to complete the questionnaires as honestly and accurately as possible. They were assured of the confidentiality of their responses. The study was conducted in compliance with the Helsinki Declaration. All the materials used in the study were reviewed and approved by the Executive Board of Esenboga International Airport and the Union of Ground Service Staff.

2.5 Data analysis

Statistical analyses were performed with SPSS (version 20.0). P values < 0.01 and 0.05 were considered statistically significant. The relationship between job satisfaction levels were analyzed by using t-test. The ANOVA test was used in order to investigate the associations between QEC and job satisfaction levels.

3 Results

Demographics. A total of 399 baggage handlers participated in this study. The age of the baggage handlers and their work experience in years are summarized in Table 1. In the sample, 42.86% of baggage handlers were 27–32 years of age and 36.34% were 21–26 years of age. As for work experience, 35.84% had 1–5 years of work experience, 25.56% had 6–10 years of work experience and 16.79% had 11–15 years of work experience.

3.1 Risk factors

Table 2 shows exposure level standards for the back, shoulder, wrist and neck according to the QEC. The scores of risk exposure for WMSDs (see Table 3) were 27±3.4 (high) for the back (static), 42±7.2 (very high) for the back (moving), 42±6.1 (very high) for the shoulder/arm, 44±1.9 (very high) for the wrist/hand, and 13±5.1(high) for the neck among the baggage handlers.

3.2 Job satisfaction

Table 4 demonstrates that job satisfaction levels of 233 baggage handlers were low (4.2250±1.10184), while the number of baggage handlers with moderate (3.1019±0.93352) levels of job satisfaction was 132. The remaining 34 baggage handlers had high levels of job satisfaction (1.1806±0.70441). These results showed that most baggage handlers were not satisfied with their job.

3.3 Relationship between risk factors and job satisfaction

In Table 5, it was found that back (static) risk levels were high in those with low (F = 5.42, p < 0.05) and moderate (F = 7.94, p < 0.01) jobsatisfaction levels. Also, back (moving) risk levels were very high in those with low (F = 4.95, p < 0.05) and moderate (F = 6.99, p < 0.01) job satisfaction levels. Low and moderate job satisfaction levels were significantly associated with very high risk levels for the shoulder/arm and wrist/hand, respectively. The analysis showed that the risk levels for the neck region were significantly high in the groups with low (F = 2.14, p < 0.05) and moderate (F = 9.09, p < 0.01) job satisfaction. Our study also revealed that a significant association was found between low (p < 0.05) and moderate (p < 0.01) job satisfaction levels and high risk levels of WMSDs. This association observed in the data, however, might be bidirectional; that is to say, WMSDs might also result in decreases in job satisfaction.

4 Discussion

This study was conducted to investigate aircraft baggage handlers’ job satisfaction levels and their exposure to risk factors for WMSDs. It was found that awkward postures, repetitive movements and forceful exertions have contributed to WMSDs. Psychological hazards associated with job content, organization and interpersonal relationships, excessive job demands, low decision latitude and low social support have been identified as potentials for musculoskeletal discomfort [24 –26]. Studies identified that poor ergonomic design of aircraft compartments and heavy bags were significant risk factors for WMSDs among baggage handlers [27 –29]. Risk factors associated with WMSDs include pushing/pulling, repetitive lifting with one or two hands, and working with hands above shoulder level. These factors are found in combination in the occupation of airline baggage handling.

The top two tasks that cause injury are “pushing baggage from the doorway into the baggage compartment of narrow body aircrafts” and “stacking baggage inside the baggage compartment of narrow body aircrafts”. It was shown that spinal moments are elevated for unexpectedly small loads [30].

Human performance in work life is a complex system of intimately related cognitive and motor components specific to humans [31]. There is a growing body of evidence relating to the link between non-physical factors (psychosocial) and musculoskeletal disorders. For example, low job satisfaction appears to be associated with musculoskeletal pains, in terms of both prevalence and severity [32].Physiological studies demonstrate that continuous work after the lifting task cannot be maintained much longer due to physical exhaustion. It is obvious that, biomechanical stresses increase psychophysiological stress [33–34]. Moreover, the literature also shows that psychosocial factors such as low commitment, low job satisfaction, poor psychosocial conditions, low demand and low decision-making are associated with development of musculoskeletal symptoms [35 –38]. Associations between job satisfaction and WMSDs occur through either a causal or effect-modifying relationship. The results of our study are also consistent with existing literature in that they demonstrate an association between WMSDs and job satisfaction.

A similar study was conducted by Tafazzol et al. [39] to analyze the WMSDs among 209 baggage handlers. They found that the most common WMSDs occurred in the lower back region, knees, neck and upper back, respectively. Almost 88% of the baggage handlers suffering from pain claimed that this pain had started after they began to work as a baggage handler. In another research, Jaworek et al. [40] studied burnout syndrome as a mediator for the effect of work-related factors on musculoskeletal complaints among 237 hospital nurses. They found that work demands and work stimuli were positively related to burnout and musculoskeletal complaints. The association between psychosocial factors and musculoskeletal problems was studied in another field of work by Larsman and Hanse [41]. They explored the relationship between these factors among 1,690 service organization workers. They observed that high psychological load with low decision making and low social support were related to increased risks of musculoskeletal problems. According to Hoole and Vermeulen [42], job satisfaction levels of aircraft pilots were influenced by the demands they had to cope with on a daily basis. This may have been due to the nature of their work environment and to the fact that they were working long and irregular shifts. To account for high job satisfaction levels, the researchers stated that these might be the result of sharing responsibilities, having more prestige, more promotion opportunities and better remuneration. On the other hand, baggage handlers, with respect to pilots, earn considerably less, have much less job security and mainly work on their own. Therefore it is plausible to assume that the baggage handlers would have lower levels of job satisfaction, as claimed in the present study.

Stewart et al. found major factors leading to WMSDs experienced by workers; one of which was their overall job satisfaction. In their study, workers reporting high levels of job satisfaction were three times less likely to have WMSDs stories in comparison to those with lower job satisfaction or to those who were unclear about their job satisfaction levels. They also claimed that having WMSDs might also impact workers’ job satisfaction negatively [43]. Therefore, their study confirms a bidirectional relationship among job satisfaction and WMSDs variables, which is again in conformity with our results.

Lee et al. [44]. investigated the relationship between work-related psychosocial factors and lower-back-related musculoskeletal disorders among long-haul international female flight attendants. They found that the flight attendants with lower-back-related musculoskeletal disorders had higher perceived psychosocial job demands, job insecurity and physical load compared with those without lower-back-related musculoskeletal disorders. As can be seen, job insecurity may lead to ‘physiological vulnerability’ of muscles and sensation of pain. Flight attendants frequently experience high physical load factors, such as pushing heavy luggage and frequent back bending, which may increase their risk of lower back WMSDs. These findings are parallel to our results. Similarly, we revealed an association between low and moderate levels of job satisfaction and high WMSD risk levels among baggage handlers.

When examining risk factors, studies attempt to limit their analyses by controlling or adjusting for individual or lifestyle factors. It is evident that WMSDs can arise from cofounders such as post injury, psychosocial variables, smoking, eating habits and alcohol consumption [45–46]. However, it is hard to control for all the possible confounding factors. Every study, regardless of how well it has been planned and conducted, has their limitations. Naturally, our study also has a number of these. Firstly, the self-reported nature of all outcome measures seems to be one limitation. The data may have been influenced by self-reported assessment techniques. In other words, the baggage handlers may have hesitated to provide accurate and honest answers. Secondly, the lack of evaluation of extrinsic and intrinsic risks factors such as current health status, past injuries, smoking and alcohol consumption, daily stressful situations and their use of medicine, also appears as a limitation. Thirdly, the male dominance in the study sample, due to the male dominance in this sector itself, is a final limitation of the study.

5 Conclusions

This study examined the exposure to risk factors for WMSDs and job satisfaction among baggage handlers in Turkish Airlines. This study, which was conducted in Ankara, can be used as a starting point of a series of comparative studies concerning job satisfaction and WMSDs among baggage handlers working in other airports in Turkey. In this study, we found high risk levels for WMSDs associated with low and moderate levels of job satisfaction among baggage handlers. Physiological and psychosocial factors may act in combination to make risks greater for WMSDs. To prevent WMSDs, it is mandatory to perform intervention methods such as addition of weight information on the existing routing tag of all baggage, storing bags upright on their short sides in order to reduce the number of lifts, posture education, and proper exercise training opportunities for baggage handlers. At the same time, improvements in the psychosocial work environment should be considered and integrated as an important element of intervention in this occupation.

Conflict of interest

There was no funding support and the authors declare no conflict of interests regarding this paper.

Footnotes

Acknowledgments

The authors would like to thank the Executive Board of Esenboga International Airport, Turkish Airlines, Turkish Ground Services and all the baggage handlers who participated in this study.

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