Cammie Chaumont Menéndez

Upper extremity pain and computer use among engineering graduate students: A replication study

BACKGROUND Recent literature identified upper extremity musculoskeletal symptoms at a prevalence of >40% in college populations. The study objectives were to determine weekly computer use and the prevalence of upper extremity musculoskeletal symptoms in a graduate student population, and make comparisons with previous graduate and undergraduate cohorts. METHODS One hundred sixty-six graduate students completed a survey on computing and musculoskeletal health. Associations between individual factors and symptom status, functional limitations, academic impact, medication use, and health services utilization were determined. Logistic regression analyses evaluated the association between symptom status and computing. Cross-study comparisons were made. RESULTS More symptomatic participants experienced functional limitations than asymptomatic participants (74% vs. 32%, P < 0.001) and reported medication use for computing pain (34% vs. 10%, P < 0.01). More participants who experienced symptoms within an hour of computing used health services compared to those who experienced symptoms after an hour of computer use (60% vs. 12%, P < 0.01). Years of computer use (OR = 1.59, 95% CI 1.05-2.40) and number of years in school where weekly computer use was more than 10 hr (OR = 1.56, 95% CI 1.04-2.35) were associated with pain within an hour of computing. Cross-study comparisons found college populations more similar than different. CONCLUSION The overall findings reinforced previous literature documenting the prevalence of upper extremity musculoskeletal symptoms in college populations, suggesting an important population for participating in public health interventions designed to support healthy computing practices and identify risk factors important to evaluate in future cohort studies. Am. J. Ind. Med. 52:113-123, 2009. (c) 2008 Wiley-Liss, Inc.

A replicated field intervention study evaluating the impact of a highly adjustable chair and office ergonomics training on visual symptoms

OBJECTIVE Examine the effects of two office ergonomics interventions in reducing visual symptoms at a private sector worksite. METHODS A quasi-experimental study design evaluated the effects of a highly adjustable chair with office ergonomics training intervention (CWT group) and the training only (TO group) compared with no intervention (CO group). Data collection occurred 2 and 1 month(s) pre-intervention and 2, 6 and 12 months post-intervention. During each data collection period, a work environment and health questionnaire (covariates) and daily health diary (outcomes) were completed. Multilevel statistical models tested hypotheses. RESULTS Both the training only intervention (p<0.001) and the chair with training intervention (p=0.01) reduced visual symptoms after 12 months. CONCLUSION The office ergonomics training alone and coupled with a highly adjustable chair reduced visual symptoms. In replicating results from a public sector worksite at a private sector worksite the external validity of the interventions is strengthened, thus broadening its generalizability.

Daily self-reports resulted in information bias when assessing exposure duration to computer use

BACKGROUND Self-reported exposure duration to computer use is widely used in exposure assessment, and this study examined the associated information bias in a repeated measures setting. METHODS For 3 weeks, 30 undergraduate students reported daily cumulative computer-use duration and musculoskeletal symptoms at four random times per day. Usage-monitor software installed onto participants personal computers provided the reference measure. We compared daily self-reported and software-recorded duration, and modeled the effect of musculoskeletal symptoms on observed differences. RESULTS The relationships between daily self-reported and software-recorded computer-use duration varied greatly across subject with Spearmans correlations ranging from -0.22 to 0.8. Self-reports generally overestimated computer use when software-recorded durations were less than 3.6 hr, and underestimated when above 3.6 hr. Experiencing symptoms was related to a 0.15-hr increase in self-reported duration after controlling for software-recorded duration. CONCLUSIONS Daily self-reported computer-use duration had a weak-to-moderate correlation with software-recorded duration, and their relationship changed slightly with musculoskeletal symptoms. Self-reports resulted in both non-differential and differential information bias.

Where and How College Students Use Their Laptop Computers

A pilot study classified the locations, furniture, input devices and postures associated with using laptop computers in a small cohort of college students. Data were collected from digital photographs of the students posing as using laptop computers in their usual workstation configurations. The observed configurations were assigned to descriptive categories and the Rapid Upper Limb Assessment (RULA) assessed the postural risk factors observed on the participants. We observed that 75% of the participants used the laptop computer in the traditional table and chair configuration; 25% of the participants used the laptop computer in untraditional configurations where they placed the computer on their laps while sitting on a lounge type couch or in their bed. Excessive shoulder flexion (61% of all configurations) and neck flexion (35%) were the postural risk factors observed commonly. RULA scores suggested the need for further postural investigation.

The epidemiology of upper extremity musculoskeletal symptoms on a college campus

OBJECTIVE The study examines temporal variations in upper-extremity musculoskeletal symptoms throughout the day, over a week and throughout the semester. METHODS 30 undergraduates were followed in a repeated measures study throughout a semester. Upper extremity musculoskeletal symptoms data were collected on handheld computers randomly throughout the day for seven days over three data collection periods. Multilevel statistical models evaluated associations between time-related predictors and symptoms. RESULTS In adjusted models, pain reported at baseline was associated with increased odds of experiencing both any symptoms (OR=15.64; 90% CI 7.22-33.88) and moderate or greater symptoms (OR=16.44; 90% CI 4.57-29.99). Any symptoms were less likely to be reported if responses occurred at 58-76 days (OR=0.66; 90% CI 0.49-0.86), 77-90 days (OR=0.29; 90% CI 0.20-0.42) and 91-117 days (OR=0.54; 90% CI 0.39-0.75) into the semester compared to 35-57 days. Similarly, responding after midnight was associated with greater odds of reporting moderate or greater symptoms (OR=21.33; 90% CI 6.49-65.97). There was no association observed for day of week and symptoms. CONCLUSION This pilot work suggests upper extremity musculoskeletal symptoms exhibit temporal variations related to time of day and days into semester. Understanding the natural history of musculoskeletal symptoms and disorders is needed when designing epidemiologic research and/or intervention studies using symptom outcome measures.

Evaluation of two posture survey instruments for assessing computing postures among college students

OBJECTIVE To determine agreement between two posture assessment survey instruments and which, if any, were correlated with experiencing upper extremity musculoskeletal symptoms. METHODS Thirty undergraduate participants had three postural assessment surveys completed, one each for three separate 7-day data collection periods during a semester. Two observation assessment tools were used, a modified Rapid Upper Limb Assessment (mRULA) for computer users for the right and left limbs and the University of California Computer Use Checklist. Concurrently, upper extremity musculoskeletal symptom experience paired to each postural assessment was measured. Lins concordance correlation coefficient evaluated survey agreement and multi-level statistical models described associations between survey responses and symptoms. RESULTS There was no agreement between the two postural assessment tool scores (p> 0.85). In adjusted models, the UC Computer Use Checklist was positively associated with symptoms occurrence (OR=1.4, 90% CI 1.2-1.6 for any symptoms; OR=1.3, 90% CI 1.0-1.6 for moderate or greater symptoms). Associations with mRULA scores were inconsistent in that they were sometimes protective and sometimes indicators of risk, depending on the covariates included in the models. CONCLUSION The mRULA for computer users and the UC Computer Use Checklist were independent of each other; however, due to the inconsistent associations with symptoms we cannot conclude one instrument is superior to the other. Our data do suggest the UC Computer Use Checklist demonstrates a traditional relationship with symptoms, where increasing scores signifiy greater risk. We observed a nontraditional relatioship with symptoms for the mRULA for computer users that needs to be further examined. This is a pilot study and, thus, findings should be interpreted as exploratory. Associations observed in the current study will be used to test hypotheses in the cohort study recently conducted.

Fatal work‐related falls in the United States, 2003‐2014

BACKGROUND Falls are the second leading cause of work-related fatalities among US workers. We describe fatal work-related falls from 2003 to 2014, including demographic, work, and injury event characteristics, and changes in rates over time. METHODS We identified fatal falls from the Bureau of Labor Statistics (BLS), Census of Fatal Occupational Injuries and estimated rates using the BLS Current Population Survey. RESULTS From 2003 to 2014, there were 8880 fatal work-related falls, at an annual rate of 5.5 per million FTE. Rates increased with age. Occupations with the highest rates included construction/extraction (42.2 per million FTE) and installation/maintenance/repair (12.5 per million FTE). Falls to a lower level represented the majority (n = 7521, 85%) compared to falls on the same level (n = 1128, 13%). CONCLUSIONS Falls are a persistent source of work-related fatalities. Fall prevention should continue to focus on regulation adherence, Prevention through Design, improving fall protection, training, fostering partnerships, and increasing communication.

The Effect of Two Office Ergonomics Field Interventions and their Replication on Visual Symptoms

Upper extremity musculoskeletal symptoms and disorders in the workplace continue to be a significant public health burden (National Research Council and Institute of Medicine, 2001). These outcomes, as they relate to computer use, are important as greater than 50% of employed adults in the United States use a computer at work (U.S. Census Bureau, 2003). Visual symptoms are also known to often coexist with upper extremity musculoskeletal symptoms with computer workers. This study examines the effect of two office ergonomic interventions, a highly adjustable chair and an office ergonomics training, on the reduction of specific visual symptoms. Additionally, findings from a replicated study site are compared with those of the original study. Multilevel logistic regression models were used to estimate the effect. In comparing the original and replication worksites we find specific visual symptom reductions occurred for the group receiving both the chair with training at the original and replicated worksite. However, the group receiving only the office ergonomics training experienced individual visual symptom reductions at the replication worksite but not the original worksite. There were differences in the specific visual symptoms affected by the office ergonomics interventions when comparing worksites.

Office Ergonomics Intervention Study Panel

Ergonomic issues in the office environment affect both workplace health and productivity outcomes. Currently the office ergonomics intervention literature is underrepresented in research studies with rigorous study designs and analytical methods. Furthermore, there exist no published replication intervention studies. Panel members are part of a multidisciplinary inter-institutional research group that conducted the same office ergonomics intervention study at two different worksites (one public and one private sector). Office workers agreeing to participate were assigned to one of two interventions - a highly adjustable chair coupled with an office ergonomics training (chair-with-training group) or the office ergonomics training alone (training-only group) - or a control group receiving the training at the end. During this discussion panel the effects of the interventions on ergonomics knowledge and computing behaviors, biomechanical changes, individual components of musculoskeletal and visual symptoms and productivity will be presented.