Adverse Effects of Sit and Stand Workstations on the Health Outcomes of Assembly Line Workers: A Cross-sectional Study

Introduction: Sitting and standing workstations can affect individual's health outcomes differently. This study aimed to assess the effects of sit and stand workstations on energy expenditure and some blood parameters, musculoskeletal symptom/pain and discomfort, fatigue, and productivity among workers of assembly line of a belt factory. Methods: This cross-sectional study was conducted on 47 male assembly line workers (24 workers in sitting workstation and 23 workers in standing workstation) with at least one year of working experience. Data were gathered via demographic/occupational characteristics, Fitbit system, medical records, Persian version of the Nordic Musculoskeletal Questionnaire (P-NMQ), Persian version of the Numeric Rating Scale (P-NRS), Persian version of the Swedish Occupational Fatigue (P-SOFI), and Persian version of the Health and Work Questionnaire (P-HWQ). Results: The findings of the present study revealed that the energy expenditure, blood glucose/triglyceride there are not statistically differences between in sitting and standing groups. In addition, the prevalence of the MSs in the neck, lower back, knees, and ankles/feet in standing group was significantly higher than the sitting group. Generally, occupational fatigue was higher among the standing group compared to sitting group. About productivity, the ‘concentration/focus’ and ‘impatience/irritability’ subscales in sitting group were higher than the standing group. Contrariwise, other subscales of the productivity, including ‘productivity’, ‘supervisor relations’, ‘non-work satisfaction’, ‘work satisfaction’ in the standing group were higher than the sitting group. Conclusions: To reduce the adverse effects of sitting and standing workstations on individual's health outcomes, planning to use sit-stand workstations is recommended. &nbsp

Comparing task performance, visual comfort and alertness under different lighting sources

The aim of this study is to compare the effects of different light sources – namely light-emitting diode (LED), compact fluorescent (FLcomp) and fluorescent with warm color temperature (FLwarm) and cool color temperature (FLcool) – on the performances, alertness, visual comfort level and preferences in a pilot study. A laboratory controlled experiment was conducted by focusing on 20 postgraduate students who volunteered to participate in a series of tests under four different light sources. “GO NO GO” task and Karolinska Sleepiness Scale (KSS) were employed to assess objective and subjective alertness, while modified OLS questionnaire was used to gauge comfort level and preferences. In addition, editing and typing tasks were carried out as a performance evaluation. Significant increase was observed in subjective and objective alertness level under FLcool condition and LED in comparison to FLwarm and FLcomp (p < 0.05). In terms of typing performances, respondents performed significantly better with regard to typing speed under FLcool than FLwarm and FLcomp. The lowest number of typing errors was made under FLcool, followed by LED, FLcomp and FLwarm. LED was the most preferred (p=0.001) and most comfortable (p=0.011) lighting condition. The study concludes that the FLcool and LED were more beneficial for alertness level and performance for both computer-based and paper-based activities

The survey of hypertension and its risk factors among industrial male workers

Hypertension is nowadays increasingly observed among the workforce population. There are many risk factors for hypertension. This study was conducted to survey hypertension and its associated risk factors among male workers of the industrial sector in Shiraz city. 500 male workers employed in Shiraz city industries participated voluntarily (age range of 20 to 59 years). A questionnaire and direct measurements were used to collect required data. The questionnaire consisted of two parts including a) demographic and occupational and b) anthropometric (height, weight, BMI, WHtR) and physiological (blood pressure and VO2-max) characteristics of the subjects. Mean (standard deviation) of systolic and diastolic Blood Pressure (BP), and Mean Arterial Pressure (MAP) in workers were 128.37±14.78, 83.13±13.10, and 98.21±13.36 mmHg, respectively. The results showed that systolic and diastolic BP, and MAP significantly were related to BMI, shift work, and smoking. Also, statistical analysis revealed that mean values of VO2-max between workers with normal and high blood pressure are significantly different. The results of this study demonstrated that domestic and occupational life style and cardio-respiratory fitness are the risk factors for hypertension in the studied workers

Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study.Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software.Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable.Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image

The Effect of Musculoskeletal Problems on Fatigue and Productivity of Office Personnel

Introduction: Work-related musculoskeletal disorders (WMSDs) can be affective on the fatigue and productivity of office workers. This study aimed to survey of the effect of musculoskeletal problems on fatigue and productivity in office personnel.Methods: In this study, 101 Iranian office workers participated. Data was gathered through demographic questionnaire, Nordic Musculoskeletal Questionnaire, Numeric Rating Scale, Persian version of Multidimensional Assessment of Fatigue Scale, and Persian version of Health and Work Questionnaire.Results: The results revealed that the highest prevalence rates of musculoskeletal symptoms in the past week were related to the neck (41.6%), lower back (41.6%), and shoulders (40.6%). The mean score of discomfort/pain in the neck, lower back, and shoulders were 1.67, 1.55, and 1.31, respectively. The severity of discomfort/pain in neck, shoulders, lower back, and thighs were correlated with total fatigue. The severity of discomfort/pain in the neck, lower back, buttock, and thighs were correlated with concentration/focus sub-scale of productivity.Conclusions: Improvement of working conditions is suggested for reducing musculoskeletal problems, fatigue decrement, and productivity increment

Effects of an ergonomic intervention program based on the PRECEDE-PROCEED Model for reducing work-related health problems and exposure risks among Emergency Medical Dispatchers

Objective: To evaluate the effectiveness of an ergonomic intervention program based on the PRECEDE-PROCEED model in terms of improving exposure risks and work-related health problems in emergency medical dispatchers. Methods: This quasi-experimental study used an interrupted time series design. Participants were 55 employees working in an Emergency Medical Communications Center in Iran. The intervention program was based on the PRECEDE-PROCEED model and included five face-to-face training sessions and installing auxiliary equipment according to best ergonomic principles. Direct observations of the emergency medical dispatchers’ working postures using the Rapid Office Strain Assessment, and a survey which included a modified Nordic Questionnaire, Work Ability Score, Visual Fatigue Questionnaire, and a Behavioral Factors questionnaire were used at three time points: baseline, one-month post-intervention, and three months post-intervention. ‎Results: The modified Nordic questionnaire showed significant reductions in pain intensity scores for neck, lower back, knee and ankle after the ergonomic intervention program. In addition, there were considerable post-training improvements in behavioral factors (knowledge and enabling factors) and working postures. No significant changes were observed in Work Ability Scores, or visual symptoms. Conclusions: An ergonomic intervention program based on a systematic framework such as the PRECEDE-PROCEED model and on-site interventions can be effective in improving and enhancing the working conditions of emergency medical dispatchers. Therefore, it is suggested that ergonomic interventions be implemented based on standard and valid behavioral change models such as PRECEDE-PROCEED model in other work environments in which musculoskeletal pain and digital eye strain are common

Investigating Glenohumeral Joint Contact Forces and Kinematics in Different Keyboard and Monitor Setups using Opensim

Background: The musculoskeletal complaints of the shoulder are prevalent in people who work with computers for a long time. Objective: This study aimed to investigate the glenohumeral joint contact forces and kinematics in different keyboards and monitor setups using OpenSim. Material and Methods: Twelve randomly selected healthy males participated in an experimental study. A 3×3 factorial design was used in which three angles were considered for the monitor and three horizontal distances for the keyboard while performing standard tasks. The workstation was adjusted based on ANSI/HFES-100-2007 standard to maintain a comfortable ergonomic posture for controlling confounding variables. Qualisys motion capture system and OpenSim were used. Results: The maximum mean range of motion (ROM) of both shoulders’ flexion and adduction was observed when the keyboard was 15 cm from the edge of the desk, and the monitor angle was 30°. The maximum mean ROM of both shoulders’ internal rotation was recorded for the keyboard at the edge of the desk. Peak forces for most right shoulder complex muscles were obtained in two setups. 3D shoulder joint moments were significantly different among nine setups (P-value<0.05). The peak anteroposterior and mediolateral joint contact forces were recorded for the keyboard at 15 cm and the monitor at zero angles (0.751 and 0.780 N/BW, respectively). The peak vertical joint contact force was observed for the keyboard at 15 cm and the monitor at 15° (0.310 N/BW).  Conclusion: The glenohumeral joint contact forces are minimum for the keyboard at 8 cm and the monitor at zero angles

Comparison of physical workload and physical work capacity among municipality cleaners in Shiraz to determine number of workers needed to counterbalance physical workload

Assessing physical workload is the most important step in deciding whether a workload is high and adopting appropriate control strategies to reduce physical workload. This study aimed to compare physical workload and Physical Work Capacity (PWC) among municipality cleaners in Shiraz to determine the number of workers needed to counterbalance physical workload. Methods The present cross-sectional study was performed on 97 municipality cleaners in Shiraz. In the first step, the participants' maximum aerobic capacity (VO2-max) was estimated in the laboratory using an ergometer bicycle and the Young Men’s Christian Association (YMCA) protocol, based on which the PWC was estimated. Secondly, energy expenditure and heart rate during work were measured using a POLAR400 device in an eight-hour shift. At the end of the work shift, the workers’ perceived physical exertion was assessed using a Rating of Perceived Exertion 6–20 (RPE 6–20) Borg scale. In the final stage, the physical workload was assessed based on the results of the two steps. Results The mean VO2-max of the cleaners and PWC were estimated to be 2.6 ± 0.66 l min−1 and 4.3 ± 1.088 kcal min−1, respectively. The average energy consumed during work was 4.122 ± 1.016 kcal min−1. The overall results of this study showed that physical workload was greater than PWC in 46% of the municipality cleaners. In addition, it was found that 12.45% workforce was required to be added to the street cleaners of Shiraz municipality to reduce the physiological workload on the employed workforce. Conclusions With respect to the high level of physical activity in a significant proportion of the cleaners, measures such as increasing the workforce are suggested

Musculoskeletal problems among workers of an Iranian communication company

Introduction: Work-related musculoskeletal disorders (WMSDs) are a common health problem throughout the world and a major cause of disability in the workplace. Awkward working posture is a main risk factor for developing WMSDs. Assessment of exposure level to WMSDs risks can be an appropriate base for planning and implementing interventional ergonomics program in the workplace. This study was conducted among workers of an Iranian communication company with the objectives of a) determination of WMSDs prevalence and b) assessment of exposure level to WMSDs risks. Materials and Methods: In this cross-sectional study, 85 randomly selected workers from assembly line and closed circuit TV (CCTV) participated. Nordic musculoskeletal questionnaire (NMQ) was used to study prevalence of WMSDs and rapid upper limb assessment (RULA) technique was applied to assess physical exposure to the risks. Results: The results of NMQ revealed that WMSDs occurred at an high rate. The highest rates of WMSDs prevalence were reported in shoulders (73%), knees (67.1%) and back (66.7%). RULA showed that the Grand Score of 88.1% of cases were high and very high (action levels 3 and 4). Significant association was found between risk level and musculoskeletal symptoms in lower back ( P<0.05). Conclusion: Given the association between RULA score and the prevalence of the problems, reducing RULA score by designing ergonomic workstation may reduce the prevalence of WMSDs among the workers

Musculoskeletal Disorders Risk Assessment in Patient Transfers among Nurses in a hospital in Tehran Using MAPO Technique and provide control measures

Background: One of the major problems in hospitals that resulting in a high prevalence of musculoskeletal disorders among employees is activities related to handling patients. This study investigated&nbsp; the prevalence of musculoskeletal disorders in people with patient handling task using MAPO index in 2015 In one of the military hospitals in Tehran. Methods: This cross-sectional study among 230 nurses in a 400-bed military hospital in Tehran. The instruments used in the study included the Nordic Questionnaire, MAPO index checklist, demographic questionnaire . Results: The main results can be the high prevalence of musculoskeletal disorders among employees, especially low back disorders, shoulder, wrist, and so on that back pain (75%) were most common among employees also the frequency of musculoskeletal disorders in female employees most of the employees were men. Conclusion: The results of this study show that the prevalence of musculoskeletal disorders among nursing personnel with patient handling task is high and therefore the need for intervention ergonomic in design environments and tools at the same time educational intervention there