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Objective: This prospective study assessed the risk of developing rotator cuff syndrome (RCS) with separate or specific combinations of biomechanical exposures measures, controlling for individual confounders. Background: Compared with other musculoskeletal disorders, rates of work-related shoulder musculoskeletal disorders have been declining more slowly. Method: We conducted up to 2 years of individual, annual assessments of covariates, exposures, and health outcomes for 393 U.S. manufacturing and healthcare workers without RCS at baseline. Task-level biomechanical exposures assessed exposure to forceful exertions (level, exertion rates, duty cycles), vibration, and upper arm postures (flexion, abduction). Hazard ratios (HRs) were calculated with Cox proportional hazard models. Results: We observed 39 incident RCS cases in 694 person-years (incidence rate = 5.62 per 100 person-years). Adjusting for confounders, we found increased risk of incident RCS associated with forceful hand exertions per minute for three upper arm posture tertiles: flexion ≥45° (≥28.2% time, HR = 1.11, CI [1.01, 1.22]), abduction ≥30° (11.9–21.2%-time, HR = 1.18, CI [1.04, 1.34]), and abduction >60° (≥4.8% time, HR = 1.16, CI [1.04, 1.29]). We failed to observe statistically significant effects for other interactions or any separate measures of biomechanical exposure. Conclusion: This study highlights the importance of assessing combinations of exposure to forceful repetition and upper arm elevation when developing interventions for preventing RCS. Application: Based on these results, interventions that reduce exposure to forceful repetition (i.e., lower force levels and/or slower exertion rates) may reduce the risk of RCS, especially when upper arm elevation cannot be avoided. [ABSTRACT FROM AUTHOR]

This article compares several methods that were used for determining hand activity level and force in a large prospective ergonomics study. The first goal of this analysis was to determine the degree of correlation between hand activity/ force ratings using different assessment methods. The second goal was to determine if the hand activity/force methods were functionally equivalent for the purpose of calculating the ACGIH® hand activity level (HAL) threshold limit value (TLV®). A final goal was to investigate reasons for potential differences between methods. More than 700 task analyses were conducted on 484 workers at three study locations. Hand activity was assessed by two methods, including a trained observer on site using a 10-point visual analog scale for hand activity level and by offsite video analysis of the same task to calculate the frequency of exertions and the work/recovery ratio. Hand force was assessed by two on-site methods: ratings of perceived exertion (RPE) using a modified Borg CR-10 scale by a trained observer and RPE by the worker performing the task. The two methods for assessing hand activity level were correlated (Spearman rank = 0.49) and produced main TLV result categories (below Action Limit, Action Limit, TLV) with percent of exact agreement ranging from 71 to 91% and weighted Kappa ranging from 0.61 to 0.75. The two RPE methods for assessing hand force were correlated (Spearman rank ranging from 0.47 to 0.69) and produced TLVs with percent of exact agreement ranging from 64 to 83% and weighted Kappa ranging from 0.52 to 0.62. Differences between methods may be explained by a number of task and subject variables that were significantly associated with higher levels of hand activity and force. In summary, this study found substantial agreement between two methods for assessing hand activity level and moderate agreement between two methods for assessing hand force. [ABSTRACT FROM AUTHOR]

The article discusses an evaluation conducted by the Health Hazard Evaluation Program of a manufacturer of premolded cable accessories for underground power distribution systems upon the request of employees who were concerned about poor ventilation, ergonomic risks and development of respiratory disease. Deficiencies in the plant's ventilation system were found and recommendation were made for the company to prevent exposures at work and rotate employees between job tasks.

This article compares several methods that were used for determining hand activity level and force in a large prospective ergonomics study. The first goal of this analysis was to determine the degree of correlation between hand activity/ force ratings using different assessment methods. The second goal was to determine if the hand activity/force methods were functionally equivalent for the purpose of calculating the ACGIH® hand activity level (HAL) threshold limit value (TLV®). A final goal was to investigate reasons for potential differences between methods. More than 700 task analyses were conducted on 484 workers at three study locations. Hand activity was assessed by two methods, including a trained observer on site using a 10-point visual analog scale for hand activity level and by offsite video analysis of the same task to calculate the frequency of exertions and the work/recovery ratio. Hand force was assessed by two on-site methods: ratings of perceived exertion (RPE) using a modified Borg CR-10 scale by a trained observer and RPE by the worker performing the task. The two methods for assessing hand activity level were correlated (Spearman rank = 0.49) and produced main TLV result categories (below Action Limit, Action Limit, TLV) with percent of exact agreement ranging from 71 to 91% and weighted Kappa ranging from 0.61 to 0.75. The two RPE methods for assessing hand force were correlated (Spearman rank ranging from 0.47 to 0.69) and produced TLVs with percent of exact agreement ranging from 64 to 83% and weighted Kappa ranging from 0.52 to 0.62. Differences between methods may be explained by a number of task and subject variables that were significantly associated with higher levels of hand activity and force. In summary, this study found substantial agreement between two methods for assessing hand activity level and moderate agreement between two methods for assessing hand force. [ABSTRACT FROM AUTHOR]