Validity of observational posture analysis methods for the elbow and shoulder.
Ergonomics in the Digital Age: Proceedings of the XVth Triennial Congress of the International Ergonomics Association, and The 7th Joint Conference of the Ergonomics Society of Korea/Japan Ergonomics Society. Seoul, Korea: Ergonomics Society of Korea, 2003 Aug; :1-4
Observational estimates of elbow and shoulder posture were obtained from 28 professional ergonomists observing four jobs on videorecording and were compared with values measured directly with a video-based motion reconstruction system. Ergonomists used categorical posture scales and a continuous visual analog scale to estimate the peak and most frequently occurring or average posture for each job. Use of a three-category scale resulted in misclassifications of peak and most frequently occurring elbow and shoulder posture with a probability averaging 30.1 %. With the six-category posture scale this probability of misclassification increased to 64.9%. Using a continuous visual analog scale correlations between the estimated postures and measured postures were statistically significant (p < 0.05) for elbow flexion and shoulder elevation (r between 0.457 and 0.662) but were considerably lower and not significant (r = 0.028 and 0.183) for the plane of shoulder elevation (horizontal shoulder abduction). Ergonomists' estimates of the temporal distribution of shoulder posture appeared to be biased such that the percentage of the cycle time in each posture category was estimated as more uniformly distributed than the measured values indicated.
Musculoskeletal-system; Ergonomics; Motion-studies; Posture; Musculoskeletal-system-disorders
Disease and Injury: Musculoskeletal Disorders of the Upper Extremities
Ergonomics in the Digital Age: Proceedings of the XVth Triennial Congress of the International Ergonomics Association, and The 7th Joint Conference of the Ergonomics Society of Korea/Japan Ergonomics Society