A Comparative Assessment of Ergonomic Risk Factors in University Personnel Using RULA and REBA Aiming to Study the Cause and Effect Relationship

The aim of this research was to conduct an ergonomic assessment of working postures and the design of computer workstations of the employees in Louisiana State University. The purpose of the study was threefold- (1) to determine the major ergonomic issues in university employees while working on computer workstations, (2) to compare the two ergonomic assessment tools (RULA and REBA) to see how similarly or differently they assess the risks present in the same working condition and (3) to develop a model that correlates between working condition, work posture and computer workstation design with their effects on musculoskeletal system. This research was constituted of a comprehensive survey (5 minutes) and a quantitative risk assessment session (20 minutes) conducted over 72 participants and their workstations in the university workplace. Along with the pre-assessment questionnaire; the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ) and two ergonomic assessment tools REBA (Rapid Entire Body Assessment) and RULA (Rapid Upper Limb Assessment) were used to quantify the ergonomic risk factors. To evaluate the computer work stations “OSHA Computer Workstations eTool - Evaluation Checklist” was used. The most number of participants (75.71%) reported to suffer from upper and lower back pain. Next to it was shoulder and upper arm (45.71%) and then forearm and wrist (42.85%) discomfort. Average RULA score (5) was more than that of REBA (4) making RULA an assessment tool with better consistency while evaluating activities of upper limb, as working on computer workstation. In 85.48% of cases RULA score was the same or more than that of REBA which indicates the strenuous work of office employees cause a disorder more in the upper limbs than that of the lower limbs. Proportional odds ordinal regression model was used to identify the most significant factors contributing towards the WMSD symptoms which are, (1) inappropriate positioning of computer monitor and exposure to prolonged awkward posture of the (2) trunk or torso, (3) shoulder-upper arm, (4) forearm-elbows and (5) wrist and hand. Three equations were developed for predicting the probabilities of a user having slightly, moderately or very uncomfortable pain when the postural and design factors are given

Modeling of VDT Workstation System Risk Factors.

The objectives of this research were to determine the most important risk factors in VDT workstations associated with physical symptoms and to investigate the interrelationship among these risk factors. A conceptual model was first developed to describe the interrelationship among the basic components in a VDT workstation system and their possible health effects. A research model was then proposed to describe the hypothesized relationships among the following categories of variables: demographic, task, workstation design, work environment, psychosocial factors, work posture, psychological stress, musculoskeletal symptoms, visual symptoms, and general physical symptoms. A method which consisted of a questionnaire, measurement and posture analysis was then developed. A field study was conducted among daily computer users in a local industry. Ninety three VDT operators participated in the study. Factor analysis was applied to the physical symptoms to help identify the underlying factors. Multiple regression was used to determine the most important factors related to the physical symptoms and the effect of interactions among the risk factors. The four factors identified among physical symptoms are: ocular discomfort, general musculoskeletal symptoms, upper extremity symptoms, and other physical symptoms. Ocular discomfort is significantly related to screen glare; both general musculoskeletal symptoms and other physical symptoms are related to fatigue; and upper extremity symptoms are related to awkward upper body posture. Many interactions between the risk factors and their effects are identified, such as, psychosocial factors and demographic, and workstation factors and working posture. Psychosocial factors are found to interact with other variables and contribute to psychological stress. The implication of this research is that both physical and social environment need to be evaluated and the interactions among the components of a VDT workstation system need to be understood in order to determine physical symptom risk factors

Physical Risk Factors Associated with the Work-Related Neck/Cervical Musculoskeletal Disorders: A Review

Work-related musculoskeletal disorders (MSD) of the neck or cervical spine result in longer sick leaves, substantial levels of human suffering, and high costs for society. Epidemiological studies clearly indicate strong associations between MSD of the neck and the work activities requiring forceful arm exertions and heavy lifting. However, most of the existing studies that evaluate the neck or cervical spine disorders focus mainly on exertions demanding sustained neck postures of repetitive arm exertions. The purpose of this study is to conduct a systematic review of existing epidemiological and experimental studies that evaluates neck or cervical spine disorders and identify the gaps in the literature for future research

The Development of a Computer Operator Risk Index to Assist Computer Operators

Computer workstation ergonomics is well into its third decade of computer related injuries and disease. Numerous studies have been completed to inform the scientific and private communities of the threats that are posed when working at a computer. There are also multiple variables involved with attaining a computer related injury or disease, and any one of those variables, or a combination of those variables, may put a computer operator at risk. The purpose of this study was to develop a computer operator risk index (CORI), based on previous literature and containing risk variables approved by an expert panel, which is designed for relatively simple calculations. The four main risk variables were time, posture, stress, and environment. This study used 100 participants (58 females and 42 males), with a mean age of 45.8 years from an age range of 20 to 64 years, who had worked at a computer for at least 1 year and worked at least three hours per day at the computer. Not only were females and males incorporated into this study, but four ethnic backgrounds as well. Participants were asked to complete a demographic survey developed for this study, as well as a combined pain/discomfort rating chart adapted from Corlett and Bishops (1976) body chart and Borg’s (1970) CR-10 pain rating scale, a self-evaluating stress test, adapted from Yang’ (2003) self-evaluation stress test, and a Likert-type survey, which was part of the CORI form, concerning the computer operator’s work environment. The remaining sections of the CORI form were completed from observations of an expert analyst. Information contained in the demographic survey and the pain/discomfort chart was used to verify previous research that stated gender was considered a risk factor in computer operators for related illnesses or injuries. In this study Chi-Square tests showed no association (X2 = 0.036,p=0.85) in gender to show this to be true. Data from the pain/discomfort chart was combined with data taken from the CORI form and found to show a significant difference with all four major risk variables. Time, posture, stress, and environmental measures at α=.05 , showed correlation (ρ\u3c.05) with the pain measures. Furthermore, the demographic survey contained data stating that some participants had been previously medically diagnosed with a computer related injury or disease and those participants, using Chi-Square testing, were compared to the results produced from the CORI equation and found to have a significant difference and high correlation (X2 = 6.683, p = .01) . From the data retrieved and calculated in this study a logistic regression model was developed that provided the expert analyst with a means with which to measure risk to computer operators. This model included the four independent variables: time, posture, stress, and environment, which are also the four main sections of the CORI form. The CORI form is recommended for initial risk screening, but is not meant to be solely dependent upon in determining the risk of a computer operator... There are several parts of this study that in themselves may be useful. The Pain/Discomfort Rating Scale may be used to discern between severity levels of pain for computer operators, the Self-Evaluation Stress test may be used to test stress levels of computer operators, and the Computer Operator Survey may be used to collect pertinent demographic information for employers

Documenting postural changes and repetition among violin players and their influence in the development of musculoskeletal disorders

The objective of this study was to document the changes in posture and the number of wrist and forearm repetitions among violin/viola players during an experiment session to attempt to understand the development of musculoskeletal disorders. Also, the perception of discomfort and pain felt by the violin/viola players in the past and the number that had been diagnosed with a disorder was documented. Finally, possible correlations were calculated between pain/discomfort with variables like the number of years playing the violin, hours of practice/day, frequency of pain, gender, and dominant hand and among different pain/discomfort variables (pain/discomfort before the experiment, after the experiment and the change in pain/discomfort throughout the experiment) and ultimately possible relationships were determined between posture and repetition with pain/discomfort. Playing a musical instrument places the highest of demands on the musculoskeletal system of musicians and is considered one of the most complex tasks the human body can perform (Steinmetz, Seidel, & Muche, 2010). This places musicians at a high risk for the development of musculoskeletal disorders. Studies have shown how musicians are at high risk for developing PRMDs ranging in prevalence from approximately 30% to almost 90% (Zaza, 1998). These high statistics was the rationale for using musicians as the focus group. This study’s population was violin/viola players (students and professionals) above the age of 18. Electrogoniometers were used to measure the postural changes and the software used with the equipment provided a count of the repetitions. The independent variables accounted for pain and discomfort while the dependent variables accounted for the demographics as well as posture and repetition. Descriptive statistics were computed for the postural changes and averages for the number of repetitions. Left Radial, Left Flexion and Left Supination displayed the most extreme postural changes, while the right hand repetitions in the radial/ulnar plane had the highest number of repetitions. Ratings for the level of pain/discomfort were averaged and a paired t-test showed that there was a significant difference between the level of pain before and after the experiment session. Correlation analyses confirmed that extreme postures of the left hand and high number of repetitions on the right hand are associated with a higher change in discomfort. Finally, predictors in the regression models for the number of pain days in a year, the level of discomfort after the experiment and the change in discomfort included repetitions of the right hand in radial/ulnar plane and gender indicating that repetitive motions and being a female could lead to increased discomfort. Future research should focus on other physical risk factors (i.e. force) as well as psychosocial factors. Future studies could also look at the differences in postural changes and repetition between genders as well as differences in how forces are applied. Other studies could focus on the difference in how both genders report pain/discomfort and which are the most affected body parts. Studies can also attempt to document postural changes in different instrument cohorts to determine which instrument could lead to higher displacements, or which postures cause more strain. In summary, this study helped conclude that more extreme postural deviations, higher number of repetitions, more hours of practice per day are and even shorter periods of practice can lead to an increase in discomfort or pain

Computer work and musculoskeletal disorders of the neck and upper extremity: A systematic review

<p>Abstract</p> <p>Background</p> <p>This review examines the evidence for an association between computer work and neck and upper extremity disorders (except carpal tunnel syndrome).</p> <p>Methods</p> <p>A systematic critical review of studies of computer work and musculoskeletal disorders verified by a physical examination was performed.</p> <p>Results</p> <p>A total of 22 studies (26 articles) fulfilled the inclusion criteria. Results show limited evidence for a causal relationship between computer work per se, computer mouse and keyboard time related to a diagnosis of wrist tendonitis, and for an association between computer mouse time and forearm disorders. Limited evidence was also found for a causal relationship between computer work per se and computer mouse time related to tension neck syndrome, but the evidence for keyboard time was insufficient. Insufficient evidence was found for an association between other musculoskeletal diagnoses of the neck and upper extremities, including shoulder tendonitis and epicondylitis, and any aspect of computer work.</p> <p>Conclusions</p> <p>There is limited epidemiological evidence for an association between aspects of computer work and some of the clinical diagnoses studied. None of the evidence was considered as moderate or strong and there is a need for more and better documentation.</p

Cumulative trauma disorders in the workplace: bibliography

"This publication provided a compilation of materials describing research conducted by NIOSH on cumulative trauma disorders in the workplace. Selected references, both NIOSH and nonNIOSH, were provided, concentrating on NIOSH activities in preventing work related musculoskeletal disorders, prevention and intervention research at NIOSH for work related musculoskeletal disorders, comments to the Department of Labor on the OSHA proposed rule on ergonomic safety and health management, a manual for musculoskeletal diseases of the upper limbs, a review of physical exercises recommended for video display tube operators, management of upper extremity cumulative trauma disorders, ergonomics and prevention of musculoskeletal injuries, and carpal tunnel syndrome. A bibliography of NIOSH publications on cumulative trauma disorders in the workplace was provided, including numbered publications, testimony, journal articles, grant reports, contract reports, and health hazard evaluations. NonNiosh references were also listed." - NIOSHTIC-2Part I. Selected NIOSH and non-NIOSH References -- A. NIOSH Activities in Preventing Work-Related Musculoskeletal Disorders -- B. Work-Related Musculoskeletal Disorders: Prevention and Intervention Research at NIOSH -- C. Comments to DOL on the Occupational Safety and Health Administration Proposed Role on Ergonomic Safety and Health Management - Part 1 -- C. Comments to DOL on the Occupational Safety and Health Administration Proposed Role on Ergonomic Safety and Health Management - Part 2 -- D. Cumulative Trauma Disorders: A Manual for Musculoskeletal Diseases of the Upper Limbs -- E. A Review of Physical Exercises Recommended for VDT Operators ) -- F. Management of Upper Extremity Cumulative Trauma Disorders -- G. Preventing Illness and Injury in the Workplace: Ergonomics and Prevention of Musculoskeletal Injuries -- H. Carpal Tunnel Syndrome -- -- Part II. Cumulative Trauma Disorders in the Workplace - Bibliography -- A. NIOSH Publications Reports -- 1. Numbered Publications -- 2. Testimony -- 3. Journal Articles -- 4. Grant Reports -- 5. Contract Reports -- 6. Health Hazard Evaluations -- -- B. Selected non-NIOSH ReferencesAlso available via the World Wide Web

An Assessment of Unmanned Aircraft System Pilot Discomfort and Fatigue

The rapid growth of unmanned aircraft system (UAS) use in both the military and civil sectors has uncovered an array of challenges within the field. In terms of human factors and ergonomics, the influence of the unique physical design of the control stations used to pilot the unmanned aircraft on local muscular fatigue and discomfort are of great concern. This study was conducted to assess the influence of two display configurations, Side-by-Side (SS) and Stacked (ST), and two chairs, Ergonomic (EC) and Captain’s (CC), on mean and median power frequencies, root mean square amplitude, posture, discomfort, workload, and seat pressure. Sixteen participants [age: 24.75 ± 2.96 years; gender: 4 female/ 12 male; height: 177.56 ± 9.09 cm; weight: 81.37 ± 16.43 kg] completed four, 2-hour simulated UAS flights for all chair/display combinations. Eight participants piloted one, 6-hour simulated UAS flight in the display/chair combination which best minimized discomfort and fatigue in the two-hour flights, EC/SS. During the two-hour flights, muscle activity, discomfort, posture, workload, and seat pressure findings indicated increased muscular fatigue and discomfort over time. Generally, the EC/SS condition appeared to best mitigate muscular fatigue and postures associated with increased risk for the development of musculoskeletal disorders. Six-hour flight data failed to provide additional insights on the influence of extended duration flights on the dependent variables of this study. Finally, linear regression analysis revealed muscle activity can likely be predicted during UAS piloting tasks using the dependent variables in this study; however, the study failed to provide evidence that models built from two-hour data can accurately predict muscle activity out to six hours