Psychometric Properties of the Persian Language Version of the System Usability Scale

Background: The System Usability Scale (SUS) is a widely used self–administered instrument for evaluating the usability of a wide range of products and services. The aims of this descriptive- methodological study were to develop and investigate the psychometric properties of the Iranian version of the SUS. Methods: The study was conducted among 202 university students from the Tabriz University of Medical Sciences, Iran. Content validity was evaluated by a panel of 10 experts. Construct validity was assessed by exploratory and confirmatory factor analyses. The internal consistency and test-retest reliability were assessed by Cronbach’s alpha and Intraclass Correlation Coefficient (ICC), respectively. Additionally the feasibility of the measure was judged by ceiling and floor effect. Results: Content validity of the short form of Iranian SUS was established. Factor analyses supported the conceptual uni-dimensionality, and thus confirmed the construct validity of the measure. The internal consistency (α =0.79) and test retest reliability (ICC = 0.96) were both approved and there was also no ceiling nor floor effect. Conclusions: The findings support the use of SUS for both practical and research settings in Iranian population

Working Conditions in Carpet Weaving Workshops and Muscu-loskeletal Complaints among Workers in Tabriz - Iran

Background: Background: Carpet weaving operations usualy involve poor working conditions that can lead to the development of musculoskeletal disorders (MSDs). This study investigated MSDs among car-pet weavers in relation to working conditions from workers' view in Tabriz City, Northwest Iran.Method: This cross-sectional and descriptive study was conducted in city of Tabriz, Iran. Data were col-lected using interviews and questionnaires. The study population consisted of 200 randomly selected healthy weavers from twenty five active carpet weaving workshops.Results: The results showed a high prevalence of musculoskeletal problems among the study population. The most commonly affected body areas were neck, lower back, ankles/feet, hands/wrists, upper back, shoulders and knees, respectively. More than half of the weavers were not satisfied with the thermal con-dition, noise level and cleanliness of the air in the workshops. The result indicated a significant relation-ship between upper back symptoms and daily working time and between lower back symptoms and the numbers of rows of knots woven in a day. Weavers' satisfaction with hand tools shape and thermal condi-tion of the workshops were associated with lower back symptoms, whereas satisfaction with weaving looms were associated with upper back complaints.Conclusion: The poor working condition of hand-woven carpet workshops such as environmental conditionsand work station design and tools should be the subject of ergonomics interventions

Accuracy, precision and reliability in anthropometric surveys for ergonomics purposes in adult working populations: A literature review

Anthropometric surveys are the most common method of gathering human morphometric data, used to design clothing, products and workspaces. The aim of this paper was to assess how current peer reviewed literature addresses the accuracy, reliability and precision regarding manual anthropometric surveys applied to adult working populations in the field of ergonomics. A literature review was performed in two electronic databases for finding relevant papers. A total of 312 papers were reviewed, of which 79 met the inclusion criteria. The results shown that the subjects of these publications are poorly addressed, so that only 27 studies mentioned at least one of the terms and none of the studies evaluated all of the terms. Only one paper mentioned and assessed precision and reliability of the measurement procedure. Furthermore, none of the publications evaluated accuracy. Moreover, the reviewed papers presented large differences in the factors that affect precision, reliability and accuracy. This was particularly clear in the measurer technique/training, measurement tools, subject posture and clothing. Researchers in this area should take more rigorous approaches and explicit indicators with their results should be presented in any report. Relevance for industry: It is important that scientific literature related to manual anthropometric measurements uses methods for assessing measurement error, since these data are often used to design clothing and workspaces as well as to calibrate non manual methods such as 3D scanners.</p

Relationships between dimensions of fatigue and psychological distress among public hospital nurses

Background: Fatigue and psychological distress are fairly common among nursing personnel,but their relationship is not clearly understood.Methods: In this cross-sectional study, we investigated the relationships between dimensions of fatigue and psychological distress among 699 public hospital nurses in Iran. The Multidimensional Fatigue Inventory (MFI–20) and General Health Questionnaire (GHQ–12)were used for evaluation of fatigue and psychological distress, respectively.Results: The total fatigue score of the MFI–20 was 52.5 (SD = 11.8). The general fatigue (mean± SD = 13.2±3.1) and reduced motivation (mean ± SD = 9.2±2.7) were the fatigue dimensions with the highest and lowest mean scores, respectively. The percentage of psychological distress(e.g., those nurses scored above the cut-off point [GHQ–12 ≥ 4]) was 29.1%. Stepwise multiple linear regression analysis indicated that general (P<0.001), physical (P<0.001) and mental(P<0.001) aspects of fatigue were significantly related to the psychological distress, so that the scores of these fatigue dimensions were significantly higher for those nurses with a higher level of psychological distress (above the cut-off point) than those with a lower level of psychological distress (below the cut-off point).Conclusion: The results emphasize the need for multi-component interventions aimed at decreasing both mental and physical fatigue, and consequently reducing the psychological distress among this group of healthcare professionals

School Bag Weight and the Occurrence of Shoulder, Hand/Wrist and Low Back Symptoms among Iranian Elementary Schoolchildren

Background: Schoolchildren usually use school bags to carry their school materials. Carryingheavy school bags can cause several problems such as musculoskeletal problems amongschoolchildren. The aim of this study was to investigate the association between the weightof school bags and the occurrence of low back, shoulder and hand/wrist symptoms amongprimary school children.Method: This cross-sectional, descriptive-analytical study was conducted among a sample of307 elementary school children in Tabriz, Iran. Data were collected using a questionnaire andfrom measurement of the school bag weight, body weight and height of each participant.Data were analysed using SPSS software.Results: The average load carried by schoolchildren was 2.9 kg, representing approximately10% of the children's body weight. Girls and lower grade children carried a greater percentageof their body weights. Approximately 86% of the children reported some kind of musculoskeletalsymptoms. The occurrence of shoulder, wrists/hands, and low back pain amongschoolchildren was 70%, 18.5% and 8.7%, respectively. The results of binary logistic regressionindicated that the school bag weight (expressed as a percentage of body weight) wasonly significantly associated with hand/wrist symptoms (P<0.05). Girls were more likely tocomplaint from low back pain than boys were. Age was significantly negatively associatedwith hand/wrist symptoms. Body mass index was also significantly associated with shouldersymptoms.Conclusion: The results indicate a high prevalence of musculoskeletal symptoms amongelementary schoolchildren. Preventive measures and appropriate guidelines with regard tosafe load carriage in schoolchildren are therefore needed to protect this age group

Prevalence and risk factors of low back pain among school age children in Iran

Background: Most available data on the prevalence and characteristics of back pain in schoolchildren is related to industrialised and developed countries. The aim of this study was to investigate the prevalence of low back pain (LBP) and potential risk factors among schoolchildren and adolescents in a developing country, Iran.Methods: A cross-sectional study was conducted among 1611 Iranian schoolchildren aged11–14 years. A self-complete questionnaire was used to assess LBP prevalence, physical leisure activities, school-related and psychosocial factors.Results: The prevalence of LBP was 34.3%. Female gender (odds ratio [OR] = 1.57, 95% CI:1.28–1.94), family member with back pain (OR = 1.82, 95% CI: 1.40–2.36), difficulty in viewing the (black)board (OR = 1.50, 95% CI: 1.13–1.99), too much homework (OR = 1.47, 95% CI:1.09–1.99), time spend carrying a schoolbag (min/d) (OR = 1.37, 95% CI: 1.01–1.85), and psychosocial factors (emotional symptoms) (OR = 2.28, 95% CI: 1.54–3.39) were independently associated with LBP. Physical activity, having a job, watching television, using a computer, playing games and schoolbag weight had no effect.Conclusion: It can be concluded that both physical and psychosocial factors influenced the risk for LBP, but emotional symptoms had a stronger association with LBP than physical factors.Knowledge about LBP in school children and adolescents could be important in assessment and treatment of such symptoms in this population

Multigroup latent class model of musculoskeletal pain combinations in children/adolescents: identifying high-risk groups by gender and age

Abstract Background To investigate the combinations of Musculoskeletal pain (MSP) (neck, shoulder, upper and low back pain) among a sample of Iranian school children. Methods The MSP combinations was modeled by latent class analysis (LCA) to find the clusters of high–risk individuals and multigroup LCA taking into account the gender and age (≤ 13 years and ≥ 14 years of age categories). Results The lowest and highest prevalence of MSP was 14.2% (shoulder pain in boys aged ≥14 years) and 40.4% (low back pain in boys aged ≤13 years), respectively. The likelihood of synchronized neck and low back pain (9.4–17.7%) was highest, while synchronized shoulder and upper back pain (4.5–9.4%) had the lowest probability. The probability of pain at three and four locations was significantly lower in boys aged ≥14 years than in other gender–age categories. The LCA divided the children into minor, moderate, and major pain classes. The likelihood of shoulder and upper back pain in the major pain class was higher in boys than in girls, while the likelihood of neck pain in the moderate pain class and low back pain in the major pain class were higher in children aged ≥14 years than those aged ≤13 years. Gender–age specific clustering indicated a higher likelihood of experiencing major pain in children aged ≤13 years. Conclusions The findings highlight the importance of gender– and age–specific data for a more detailed understanding of the MSP combinations in children and adolescents, and identifying high-risk clusters in this regard

Pinch Strengths in Healthy Iranian Children and Young Adult Population

Background: Data on the physical strength capabilities are essential for design-ing safe and usable products and are useful in a wide range of clinical settings especially during treatment of disease affecting the function of the hand. The purpose of this study was to determine peak lateral pinch strength, key pinch strength, tip-to-tip pinch strength and three-jaw pinch strength exertions in a healthy Iranian children and young adult population.Methods: The study was conducted among 511 participants (242 males and 269 females) aged 7-30 years. Measurements were carried out with both dominant and non-dominant hands in standard sitting posture using a B&L pinch gauge. Two repetitions of each strength measurement were recorded for each condition and the average value of the two trials was used in the subsequent analysis.Results: The results showed significant differences in the pinch strength data in terms of the age, gender and hand dominance. The lateral pinch strength, key pinch strength, tip-to-tip pinch strength and three-jaw pinch strength exertions by females were 68.4%, 68.8%, 78.8% and 81.8% of those exerted by males, respectively. Strength exertions with the non-dominant hand were 6.4%, 5.2%, 6.6% and 5.1% lower than strength exertions of the dominant hand for the lat-eral pinch strength, key pinch strength, tip-to-tip pinch strength and three-jaw pinch strength exertions, respectively.Conclusion: These findings can be used to fill the gaps in strength data for Iranian population