Interactive model of subsidiary behaviors, work performance and autonomic nerve activity during visual display terminal work.

Objectives: The aims of the study were to investigate the systematic classification of subsidiary behaviors during visual display terminal (VDT) work and discuss the interpretation of these behaviors through an interactive model of subsidiary behaviors, work performance and autonomic nerve activity.

Methods: Twelve university students were instructed to perform continuous 120-min English transcription tasks in a sedentary posture. Data on subsidiary behaviors, work performance (mean keystroke and mean error rates), and autonomic nervous system balance (log-transformed low frequency (LF) / high frequency (HF) ratio) were recorded every 5 min during VDT work.

Characterizing recovery of sleep after four successive night shifts.

The purpose of this study was to characterize the recovery pattern of sleep following simulated, four successive night shifts in ten healthy men (22.9 + or - 3.2 yr).

Effects of adjustable sit-stand VDT workstations on workers' musculoskeletal discomfort, alertness and performance.

Adjustable sit-stand workstations, which are designed to allow workers to sit and stand autonomously while working, were examined to identify the effects on workers' musculoskeletal discomfort, alertness and performance. Twenty-four healthy subjects participated in the study. The subjects were required to do an English transcription task for 150 min under the following conditions: 1) sitting at standard workstations (Standard), 2) sitting on a chair with the work surface elevated to standing position (High-chair) and 3) a combination of 10-min sitting and 5-min standing with the same setting as that in the high-chair condition (Sit-stand).

[Characteristic patterns of fatigue feelings on four simulated consecutive night shifts by "Jikaku-sho shirabe"].

The aim of the present study was to reveal characteristic patterns of fatigue feelings on consecutive night shifts by a questionnaire for work-related fatigue feelings "Jikaku-sho shirabe". Ten healthy males (Mean +/- SD: 22.9 +/- 3.

High-amplitude QRS complex in the electrocardiograms of normotensive people and risk of subsequent hypertension.

Background: Left ventricular hypertrophy sometimes develops in normotensive people with a genetic background for hypertension. The aim of this case-control study was to test the hypothesis that a high-amplitude QRS complex (high-QRS) is indicative of risk of eventual hypertension.

Methods: We reviewed medical charts that included blood pressure data obtained every 6 months from 7011 Japanese workers.

Elevated white blood cell count as a risk factor of coronary artery disease: inconsistency between forms of the disease.

White blood cells (WBC) destabilize coronary artery plaques and an elevated WBC count is a risk factor of coronary artery disease (CAD). Nevertheless, the differences between the forms of CAD in the relationship with WBC count remain to be elucidated. To study these differences, we reviewed the health-checkup records from 1994 to 1999 for 6021 Japanese post office workers without any cardiovascular abnormalities.