Development of the fall prevention index on the movable scaffold for construction workers.

BACKGROUND: Falls are caused by difficulties in maintaining stable posture or center of pressure (COP). Studies on construction-related falls and their prevention are limitedOBJECTIVE:To propose a fall prevention index (FPI) based on the working environment at height (with or without a handrail) and experience of workers on movable scaffolds. METHODS: Thirty participants were enrolled, and their COP distances were measured at the time of falling in the anterior-posterior (AP), mediolateral (ML), and diagonal directions. RESULTS: The probability of falling in the diagonal direction is almost zero for workers with more than 20 years of experience and that in the AP direction is almost zero for workers with up to 30 years of experience. There was almost zero probability of falling in the ML direction for workers with >15 years of experience. This index can be used as a tool for predicting the risk of falls, screening workers, and implementing proactive measures to prevent falling accidents on work sites. CONCLUSIONS: Preventing falls from movable scaffolds (and height in general) is needed in the construction industry. We propose a fall prevention index based on the working environment (at height, with or without handrail) and experience of workers on movable scaffolds.

Investigation of a strategy for improving the Size Korea anthropometric database.

BACKGROUND: It is important for the designers and manufacturers to produce products with good usability and fit. The Korean anthropometric database is important as Korean industries focus on developing products with better usability. OBJECTIVE: To investigate how well the present national Size Korea anthropometric database adopted by companies and industries in Korea, in particular how well the dynamic anthropometric data are adopted. METHODS: The investigation methodology consisted of three stages: literature review, expert review and in-depth interviews. The literature review was based on a PubMed search. An online survey of 1,000 Korean civilians was carried out using a questionnaire developed by experts in anthropometry. Finally, industry professionals and professors participated in in-depth interviews. RESULTS: The anthropometric data appear to be used mainly by universities and research institutions in Korea. Many industries including the automobile, medical, shipping, mattress and construction industries need dynamic anthropometric data, such as range of motion, angle between body parts, spinal curvature, centre of pressure and so on. CONCLUSIONS: The Size Korea database-building process needs to be modified to take into account the needs of companies and industries.

Development of an Algorithm for Stroke Prediction: A National Health Insurance Database Study in Korea.

BACKGROUND: Stroke is the second leading cause of death worldwide and remains an important health burden both for the individuals and for the national healthcare systems. Potentially modifiable risk factors for stroke include hypertension, cardiac disease, diabetes, and dysregulation of glucose metabolism, atrial fibrillation, and lifestyle factors. OBJECTS: We aimed to derive a model equation for developing a stroke pre-diagnosis algorithm with the potentially modifiable risk factors. METHODS: We used logistic regression for model derivation, together with data from the database of the Korea National Health Insurance Service (NHIS). We reviewed the NHIS records of 500,000 enrollees. For the regression analysis, data regarding 367 stroke patients were selected. The control group consisted of 500 patients followed up for 2 consecutive years and with no history of stroke. RESULTS: We developed a logistic regression model based on information regarding several well-known modifiable risk factors. The developed model could correctly discriminate between normal subjects and stroke patients in 65% of cases. CONCLUSION: The model developed in the present study can be applied in the clinical setting to estimate the probability of stroke in a year and thus improve the stroke prevention strategies in high-risk patients. The approach used to develop the stroke prevention algorithm can be applied for developing similar models for the pre-diagnosis of other diseases.

Evaluation of quantitative glare technique based on the analysis of bio-signals.

This laboratory study evaluated the effect of glare source (halogen, HID and LED) and its illumination levels (0.7, 2 and 5 lx) using a quantitative methodology. Pupil diameter and electroencephalography were measured using FaceLab and Biopac systems, respectively. The discomfort glare was assessed subjectively with Borg's CR-10 scale. Twenty healthy subjects participated. Pupil size was significantly affected by the headlamp type and illumination condition. Pupil size was smaller when exposed to the LED headlamp than other headlamps (Halogen > HID > LED). In addition, when the illumination increased, pupil size decreased (0.7 lx > 2 lx > 5 lx). Also, driver's discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver. These results can be applied to design and development of headlamps. Further investigation is necessary with adopted methodology to evaluate other headlamps in different illumination conditions. Practitioner Summary: This study evaluated pupil size and electroencephalography under different glare source (halogen, HID and LED) and illumination levels (0.7, 2 and 5 lx). Driver's discomfort increased when pupil size was small, and theta waves were high. This discomfort may cause reduced attention and safety of the driver.

The effects of experience and the presence of a scaffold handrail on postural and spinal stability in construction workers.

The goal of this study was to quantify the effect of experience and handrail presence on trunk muscle activities, rotational spinal stiffness and postural stability of construction workers. We evaluated spinal stability, and objective and subjective postural stability in 4 expert and 4 novice construction workers who were performing a manual task in a standing position on a scaffold, with and without a safety handrail. Center of pressure was computed using measurements taken with insole pressure transducers. Muscle activity was monitored using surface electrodes placed on 8 trunk muscles that predicted active trunk rotational stiffness. Standard deviations of the center of pressure, back muscle activity and spinal stiffness were greater in novices and in the absence of a handrail. We infer that the risk of a fall due to postural and spinal instability may be greater with a lower level of experience and in the absence of a safety handrail.

Legibility difference between e-books and paper books by using an eye tracker.

The aim of the study was to evaluate the difference in legibility between e-books and paper books by using an eye tracker. Eight male and eight female subjects free of eye disease participated in the experiment. The experiment was conducted using a 2 × 3 within-subject design. The book type (e-book, paper book) and font size (8 pt, 10 pt, 12 pt) were independent variables, and fixation duration time, saccade length, blink rate and subjective discomfort were dependent variables. In the results, all dependent variables showed that reading paper books provided a better experience than reading e-books did. These results indicate that the legibility of e-books needs further improvement, considering fixation duration time, saccade movement, eye fatigue, device and so on. PRACTITIONER SUMMARY: This study evaluated the legibility difference between e-books and paper books from the viewpoint of readability, eye fatigue and subjective discomfort by using an eye tracker. The results showed that paper books provided a better experience than e-books. This indicates that the readability of e-books needs further improvement in relation to paper books.

Prevalence of playing-related musculoskeletal disorders in traditional Korean string instrument players.

This study was performed to investigate the prevalence of musculoskeletal disorders in players of a variety of traditional Korean classical instruments: gayageum, geomungo, ajaeng, and haegeum. A large percentage of these musicians suffer from musculoskeletal pain of various body parts. However, there has been no research regarding the extent of musculoskeletal disorders in players of these instruments. Through a focus group interview, a questionnaire was developed to investigate musculoskeletal disorders. The questionnaire consisted of four parts: demographic factors, performance factors, musculoskeletal disorder symptoms, and musculoskeletal disorder experiences. Eighty-six expert players participated in this survey. The data from the survey were analyzed by correlation analysis and chi-squared analysis. Musculoskeletal disorders symptoms and severe pain were reported in the neck, shoulder, back and knee. These problems were statistically related to height for players of the gayageum and geomungo. In addition, the musculoskeletal disorder experience of geomungo players was correlated with age and career length. The symptoms of playing-related musculoskeletal disorders in traditional Korean music players were reported as being mostly observed in the neck, shoulder, back, and knee. In addition, these symptoms were related to various demographic factors such as age, height, career length, and hobby styles. The results of this study can be used as preliminary data for developing guidelines to prevent traditional Korean musical instrument players from developing musculoskeletal injuries.

The effects of safety handrails and the heights of scaffolds on the subjective and objective evaluation of postural stability and cardiovascular stress in novice and expert construction workers.

Work performed on scaffolds carries the risk of falling that disproportionately threatens the safety and health of novice construction workers. Hence, objective measures of the postural stability, cardiovascular stress, and subjective difficulty in maintaining postural balance were evaluated for four expert and four novice construction workers performing a manual task in a standing posture on a scaffold with and without safety handrails at two different elevation heights. Based on a multivariate analysis of variance, the experience, scaffold height, and presence of a handrail were found to significantly affect measures of the postural stability and cardiovascular stress. At a lower level of worker experience, a higher scaffold height, and in the absence of a handrail (which may correspond to higher risk of a fall), postural stability was significantly reduced, while cardiovascular stress and subjective difficulties in maintaining postural balance increased. We emphasize the importance of training and handrails for fall prevention at construction sites.