Follow-up study of musculoskeletal disorders 20 months after the introduction of a mouse-based computer system.
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OBJECTIVES: This study attempted to determine whether musculoskeletal health is influenced by mouse-intensive computer work. METHODS: The neck-upper limbs of 148 air-traffic controllers (71 women, 77 men) with demanding computer work were examined before (baseline) and a median of 20 months after (follow-up) a change from varied computer work to a mouse-based system, causing a significant change in the physical exposure of the workers (eg, lower variation of work postures and less rest in the forearm extensor muscles, as assessed by technical measurements). Complaints (according to a Nordic questionnaire), diagnoses (standardized physical examination), and psychosocial work environment (Copenhagen Psychosocial Questionnaire) were recorded. RESULTS: The air traffic controllers had consistently higher prevalences of disorders in the elbows-hands in the follow-up than at the baseline (complaints 30% versus 18%, P=0.03; diagnoses 10% versus 3.4%, P=0.02). The predominance of right-arm disorders was more pronounced in the follow-up than at the baseline. For the neck-shoulders-upper back, there was no consistent difference between the baseline and follow-up values; disorders increased significantly among the "young" controllers (< or =37 years), but not among the "older" ones. Perceived decision latitude decreased, while social support increased, but these changes did not explain the disorders that appeared in the elbows-hands. CONCLUSIONS: Intensive mouse-based computer work, with constrained posture and little rest in the forearm muscles, was associated with an increased risk of disorders in the elbows-hands. This finding should be considered for similar technological developments in other settings. (+info)
Heritage of army audiology and the road ahead: the Army Hearing Program.
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Modification of certain medical standards and procedures and duration of certain medical certificates. Final rule.
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This rule extends the duration of first- and third-class medical certificates for certain individuals. A first-class medical certificate is required when exercising airline transport pilot privileges and at least a third-class medical certificate when exercising private pilot privileges. Certain conforming amendments to medical certification procedures and some general editorial amendments are also adopted. The intent of this action is to improve the efficiency of the medical certification program and service provided to medical certificate applicants. (+info)
Hearing deficit in a birth cohort of U.S. male commuter air carrier and air taxi pilots.
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PURPOSE: Long-term exposure to multiple risk factors in aviation may place pilots at excess risk of developing hearing deficits. We examined the incidence and risk factors for hearing deficit in a birth cohort of male commuter and air taxi pilots. METHODS: The subjects (N = 3019), who were 45-54 yr of age and held Class I medical certificates in 1987, were followed up from 1987 to 1997 through the medical certification system of the Federal Aviation Administration (FAA). In this study, hearing deficit refers to the FAA pathology code 220 (defective hearing, deafness, not elsewhere classified). Poisson regression modeling based on generalized estimation equations was used to assess the associations between pilot characteristics and the risk of developing hearing deficit. RESULTS: The 10-yr follow-up accumulated a total of 20,671 person-years and 574 incident cases of hearing deficit, yielding an incidence rate of 27.8 per 1000 person-years. Compared with age 45-49 yr, the risk of developing hearing deficit at age 50-54 yr, 55-59 yr, and 60-64 yr increased by 12% [adjusted relative risk (RR) 1.12, 95% confidence interval (CI) 0.98-1.30], 34% (RR 1.34, 95% CI 1.13-1.59), and 79% (RR 1.79, 95% CI 1.20-2.67), respectively. CONCLUSIONS: Hearing deficit is prevalent among commuter air carrier and air taxi pilots and the risk of hearing deficit increases progressively with pilot age. Effective programs for preventing excess hearing loss in the pilot population are warranted. (+info)
Ordered cyclic motifs contribute to dynamic stability in biological and engineered networks.
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The relationship between temperamental traits and the level of performance of an eye-hand co-ordination task in jet pilots.
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When assessing the psychological suitability for the profession of a pilot, it is important to consider personality traits and psychomotor abilities. Our study aimed at estimating the role of temperamental traits as components of pilots' personality in eye-hand co-ordination. The assumption was that differences in the escalation of the level of temperamental traits, as measured with the Formal Characteristic of Behaviour-Temperament Inventory (FCB-TI), will significantly influence eye-hand co-ordination. At the level of general scores, enhanced briskness proved to be the most important trait for eye-hand co-ordination. An analysis of partial scores additionally underlined the importance of sensory sensitivity, endurance and activity. The application of eye-hand co-ordination tasks, which involve energetic and temporal dimensions of performance, helped to disclose the role of biologically-based personality traits in psychomotor performance. The implication of these findings for selecting pilots is discussed. (+info)
Spatial disorientation in gondola centrifuges predicted by the form of motion as a whole in 3-D.
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INTRODUCTION: During a coordinated turn, subjects can misperceive tilts. Subjects accelerating in tilting-gondola centrifuges without external visual reference underestimate the roll angle, and underestimate more when backward-facing than when forward-facing. In addition, during centrifuge deceleration, the perception of pitch can include tumble while paradoxically maintaining a fixed perceived pitch angle. The goal of the present research was to test two competing hypotheses: 1) that components of motion are perceived relatively independently and then combined to form a three-dimensional (3-D) perception; and 2) that perception is governed by familiarity of motions as a whole in three dimensions, with components depending more strongly on the overall shape of the motion. METHODS: Published experimental data from existing tilting-gondola centrifuge studies were used. The two hypotheses were implemented formally in computer models, and centrifuge acceleration and deceleration were simulated. RESULTS: The second, whole-motion oriented hypothesis better predicted subjects' perceptions, including the forward-backward asymmetry and the paradoxical tumble upon deceleration. The predominant stimulus at the beginning of the motion and the familiarity of centripetal acceleration were important factors. CONCLUSION: Three-dimensional perception is better predicted by taking into account familiarity with the form of 3-D motion. (+info)