Usefulness of the Rapid Office Strain Assessment (ROSA) tool in detecting differences before and after an ergonomics intervention.

BACKGROUND: Most ergonomics studies on office workstations evaluate the effects of an intervention only by subjective measures such as musculoskeletal pain and discomfort. Limited evidence has been provided regarding risk factor reduction in office environments through standardized methods assessments. The Rapid Office Strain Assessment (ROSA) tool can provide an estimation of risk factor exposure for office workers as a means by which the outcome of interventions can be quantified. PURPOSE: The aim of the study was to evaluate if ROSA scores reflect changes in risk factors after an ergonomics intervention among office workers. METHODS: Office workers (n = 60) were divided into two groups. The experimental group received a workstation intervention and the control group received no intervention. Changes in ROSA scores were compared before and after the intervention in both groups. RESULTS: Statistically significant reductions in the ROSA final and section scores occurred after the intervention in the experimental group with (mean reduction of 2.9, 0.8 and 1.6 points for sections A, B and C, respectively). In contrast, no differences were detected in the control group (mean increase of 0.1 point for sections A and C and mean reduction of 0.1 point for Section B). CONCLUSIONS: These findings show that ROSA scores reflect changes in risk factors after an ergonomics intervention in an office environment. Consequently, this tool can be used for identifying and controlling risk factors among computer workers, before and after interventions.

Assessment of Joint Angle and Reach Envelope Demands Using a Video-Based Physical Demands Description Tool.

BACKGROUND: Current methods for describing physical work demands often lack detail and format standardization, require technical training and expertise, and are time-consuming to complete. A video-based physical demands description (PDD) tool may improve time and accuracy concerns associated with current methods. METHODS: Ten simulated occupational tasks were synchronously recorded using a motion capture system and digital video. The tasks included a variety of industrial tasks from lifting to drilling to overhead upper extremity tasks of different cycle times. The digital video was processed with a novel video-based assessment tool to produce 3D joint trajectories (PDAi), and joint angle and reach envelope measures were calculated and compared between both data sources. RESULTS: Root mean squared error between video-based and motion capture posture estimated ranged from 89.0 mm to 118.6 mm for hand height and reach distance measures, and from 13.5° to 21.6° for trunk, shoulder, and elbow angle metrics. Continuous data were reduced to time-weighted bins, and video-based posture estimates showed 75% overall agreement and quadratic-weight Cohen's kappa scores ranging from 0.29 to 1.0 compared to motion capture data across all posture metrics. CONCLUSION AND APPLICATION: The substantial level of agreement between time-weighted bins for video-based and motion capture measures suggest that video-based job task assessment may be a viable approach to improve accuracy and standardization of field physical demands descriptions and minimize error in joint posture and reach envelope estimates compared to traditional pen-and-paper methods.

Evaluation of a virtual reality head mounted display as a tool for posture assessment in digital human modelling software.

The purpose of this work was to assess the feasibility of using a head mounted display with a motion capture system to simulate real world occupational tasks. Participants performed a pointing task under 3 conditions: (1) real environment (REA), (2) virtual environment with auditory stimulus (VEA) and (3) virtual environment with visual stimulus (VEV). End point error, movement time and peak fingertip velocity were calculated for each discrete point event. Upper extremity joint angles were calculated at the end-state for each point and did not significantly differ between real and virtual conditions. There was significantly greater target error in virtual conditions, compared to the real condition. Peak pointing velocity was slower and movement time was longer during virtual conditions. The similarity of joint angles between real and virtual conditions suggests future use of posture-based ergonomic assessments for use with virtual reality task simulations using Oculus Rift and Siemens Jack.

Rapid office strain assessment (ROSA): Cross cultural validity, reliability and structural validity of the Brazilian-Portuguese version.

Forty-three occupational health professionals (observers) and 90 workers were enrolled in this study to perform the cross-cultural adaptation of the Rapid Office Strain Assessment into Brazilian Portuguese (ROSA-Br) and evaluate its psychometric properties. After cross-cultural adaptation, the measurement properties were checked in three stages: study 1: pre-testing (27 observers rated 15 office worker videos), study 2: intra- and inter-observer reliability (26 observers rated 15 office worker videos), and study 3: validity and accuracy of ROSA-Br final scores (90 office workers). For the ROSA scores, acceptable intraclass correlation coefficients were found for 75% and 86% of the intra-observer reliability comparisons for non-trained and trained observers, respectively, and for 100% of the inter-observer reliability comparisons (0.43-0.86). For construct validity, moderate correlations were observed for 70% of the comparisons between ROSA final scores and other ergonomic instruments. Moderate accuracy was observed for a ROSA-Br final score of 6 (AUC [area under the curve] = 0.72, 0.89). Taken together, these results support the use of the ROSA-Br for ergonomic field assessments and research.

Major League Baseball pace-of-play rules and their influence on predicted muscle fatigue during simulated baseball games.

Major League Baseball (MLB) has proposed rule changes to speed up baseball games. Reducing the time between pitches may impair recovery from fatigue. Fatigue is a known precursor to injury and may jeopardise joint stability. This study examined how fatigue accumulated during baseball games and how different pace of play initiatives may influence fatigue. Pitcher data were retrieved from a public database. A predictive model of muscle fatigue estimated muscle fatigue in 8 arm muscles. A self-selected pace (22.7 s), 12 s pace (Rule 8.04 from the MLB) and a 20 s rest (a pitch clock examined in the 2014 Arizona Fall League (AFL)) were examined. Significantly more muscle fatigue existed in both the AFL and Rule 8.04 conditions, when compared to the self-selected pace condition (5.01 ± 1.73%, 3.95 ± 1.20% and 3.70 ± 1.10% MVC force lost, respectively). Elevated levels of muscle fatigue are predicted in the flexor-pronator mass, which is responsible for providing elbow stability. Reduced effectiveness of the flexor-pronator mass may reduce the active contributions to joint rotational stiffness, increasing strain on the ulnar collateral ligament (UCL) and possibly increasing injury risk.

Development and evaluation of an office ergonomic risk checklist: ROSA--rapid office strain assessment.

The Rapid Office Strain Assessment (ROSA) was designed to quickly quantify risks associated with computer work and to establish an action level for change based on reports of worker discomfort. Computer use risk factors were identified in previous research and standards on office design for the chair, monitor, telephone, keyboard and mouse. The risk factors were diagrammed and coded as increasing scores from 1 to 3. ROSA final scores ranged in magnitude from 1 to 10, with each successive score representing an increased presence of risk factors. Total body discomfort and ROSA final scores for 72 office workstations were significantly correlated (R = 0.384). ROSA final scores exhibited high inter- and intra-observer reliability (ICCs of 0.88 and 0.91, respectively). Mean discomfort increased with increasing ROSA scores, with a significant difference occurring between scores of 3 and 5 (out of 10). A ROSA final score of 5 might therefore be useful as an action level indicating when immediate change is necessary. ROSA proved to be an effective and reliable method for identifying computer use risk factors related to discomfort.