Iranian Journal of Ergonomics

---

Introduction: Musculoskeletal disorders are the most common occupational diseases and injuries. The importance of control and reduction the discomfort to the extent that in many countries, Prevention of work-related musculoskeletal disorders among workers has been considered as one of the national priorities. Methods: the cross-sectional study was carried out as an intervention in a chicken slaughterhouse. In order to determine the prevalence of musculoskeletal disorders, Cornell questionnaire was used. By identifying the tasks that are very high in musculoskeletal disorders posture evaluate was conducted and then the proportional to risk level tasks, engineering and management measures was performed. Given that most tasks are the kind of manual handling and carrying, were used the KIM methods for evaluating posture before and after of intervention. Results: The results of the Cornell questionnaire showed that the highest risk level Belongs to the neck, shoulders, back, arms and waist. Also evaluate by the KIM method the highest level of risk was estimated, the task of throwing the box and pick up the ice with the risk level 4 score, that after the intervention, decreased to the 2 score. Improvement obtained for all interventions on the average about 46.37 percent. The McNemar test was also significant difference between the results obtained before and after intervention. Conclusion: ergonomic problems have undesirable effects on employee health and productivity. This study, engineering and management interventions could significantly reduce the amount of corrective measures to improve working conditions in different parts of the company.

---

Introduction: The analysis posture methods are counted as a source of investigating the risk of musculoskeletal disorders related to work. Personal digital assistant is a small mobile system with an operative system that can install on various programs such as posture analysis methods. Method: Firstly, three ways for posture analysis such as QEC, RULA and REBA determined. Afterward, the program of posture analysis methods written by BASCOM software with Basic language in IC MICRO CONTROLLER belong to AVR family, and interned in IC by programmer for making PDA. PDA Usability evaluated by Persian version of system usability scale questionnaire after specifying the validity and reliability of questionnaire. Finally, postural analysis was compared using a PDA with paper method. Results: The system usability scale of PDA method is 84.2±6.2 which that got B rank and placed in very well situation. Cronbach's Alpha and Pierson correlation coefficient belongs to System usability Scale are 0.716 and 0.888, sequentially (p˂0.001). The comparison between PDA and paper methods show us that time’s operation for analysis posture in PDA method is less than half of the time in papers method. Also, the probability of calculation errors in PDA is zero, but in paper method has tolerance between 2.33 to 8.66. Conclusion: Use of personal digital assistant for analysis posture solved the problems related to delay achieving to final results and removed the error probability in final results.

---

Introduction: Firefighting is amongst jobs that require high physical strength and high aerobic capacity. These are required because of the nature and the physical demands of the job. The maximum aerobic capacities of firefighters were investigated using the step test.

Methods: This cross-sectional descriptive-analytical study was conducted on 73 firefighters. At first, demographic information was collected by a questionnaire. Then, the step was built with adjustable height, for step testing, and using the Francis method, maximum aerobic capacity of the participants, was studied. The results of the questionnaire and step test were analyzed by the SPSS 16 software.

Results: maximum aerobic capacity of firefighters was calculated as 3.65 L/min and 47.4 mL/kgmin. Moreover, the results of statistical analysis revealed a significant relationship between body mass index and exercise, and maximum aerobic capacity (P ˂ 0.05). Also no significant relationship was found between maximum aerobic capacity, age, smoking and work-related fatigue (P > 0.05).

Conclusions: Studying the firefighters cardiorespiratory capacity, to reduce the probability of firefighters injuries is very important due to occupational sensitivity and having to perform difficult tasks under demanding circumstances. The results of this study showed that maximal oxygen uptake (vo2 max) and cardiopulmonary capacity of examined firefighters are greater than the minimum amount recommended by the international association of firefighters, which can be due to regular physical fitness programs conducted by the organization.

---