Iranian Journal of Ergonomics

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Introduction: Musculoskeletal disorders (MSDs) are the main causes of work related injuries and disabilities in developed as well as developing countries. Few studies have considered different interactive effects of individual and work-related factors on MSDs, simultaneously. Methods and Materials: Data were gathered by Nordic questionnaire and Quick Exposure Check (QEC) method and were analyzed using logistic regression model in order to study the correlation between the prevalence and intensity of MSDs and individual and work-related factors. Results: More than half of all participants (61.6%) reported suffering from one form of MSDs during the past 6 months. Results showed that risk factors such as work stress, sleeping position, lifestyle and poor posture had an important role in the prevalence and intensity of MSDs. Discussion: The effect of a risk factor is constantly in interaction with other risk factors, and is modified by other factors. Participatory ergonomic intervention programs, work station intervention, ergo stress intervention and life-style interventions were suggested in order to decrease the prevalence and intensity of MSDs.

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Introduction: Listening to music during physical activity reduces the perceived stress on body. Hence, this study aimed to evaluate the effects of music genre and sound pressure level on calorie consumption and physical performance of students during treadmill tests.

Methods: In this cross-sectional study, 27 students were randomly selected. A demographic questionnaire, Borg Rating of Perceived Exertion Scale (RPE 6-20), and the Physical Activity Readiness Questionnaire (PAR-Q) were used for data collection. During flat and sloped treadmill running (five minutes at 6 km/hour), two pieces of music with fast and slow tempo (200 and 70 beat per minute) were also played at two sound pressure levels (60 and 80 dB). During the exercise, the students’ heart rate and calorie consumption were measured by a calorimeter (Beurer PM100). At each stage, the physical performance of the participants was estimated using the relevant equation.

Results: The students had the lowest physical performance (61.48) when no music was played and the highest physical performance (92.48) with slow, loud music. The mean heart rate, calorie consumption, and perceived exertion were maximized without music and minimized when slow, loud music was played.

Conclusion: Playing soft music at high sound pressure levels can promote physical performance during exercise by decreasing heart rate, calorie consumption, and perceived exertion.

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Introduction: Heavy load lifting or occupational and individual factors are effective hazard agents in the occurrence of musculoskeletal disorders. Therefore, the aim of the present study was investigating the correlation of musculoskeletal disorders with work ability index and allowable load lifting limit.

Methods: This analytical and cross-sectional study was conducted using census (n = 60) among the kitchen workers in Qazvin teaching hospitals in 2016. Data were collected through questionnaires including pain prevalence, work ability index and allowable load lifting limit. Data was analyzed by single and multiple regression logistic using SPSS 16 software.

Results: The highest prevalence was observed in the lower back (78.3%). Of the workers, 61.7% reported a good level of work ability index and 58.3% of the workplaces were in unsafe conditions of load handling. Unsafe condition alone increased the prevalence of shoulder and neck pain about 7 times and the lower back pain 4 times, and in interaction with other risk factors, the prevalence of neck and shoulder pains had 25 and 28 times increase, respectively. Also, subjects with good levels of ability compared to subjects with excellent levels of ability were 9 times more in exposure of musculoskeletal disorders.

Conclusions: Risk factors such as body mass index, work ability and allowable load lifting limit can affect the prevalence of musculoskeletal disorders. So, selection of subjects with good and excellent work ability levels and compliance with the load limit are the effective solutions in increasing the productivity and reducing musculoskeletal disorders among kitchen workers.