Vagal and sympathetic activity in burnouts during a mentally demanding workday.

OBJECTIVE: We study differences in task performance and related sympathetic-vagal reaction patterns between burnouts and controls during a mentally demanding workday. METHOD: Thirty-nine adults with burnout and 40 healthy controls performed mental tasks during a simulated workday. At pretest, just before lunch (lunch test) and at the end of the day (posttest), a Stroop color word task was administered as a probe task. Efficiency (the relation between performance and effort during the probe task), performance (reaction time and errors), and effort (self-report) were measured, as well as cardiovascular indices of sympathetic (blood pressure) and vagal (respiratory sinus arrhythmia) activity. RESULTS: Performance and effort investment of both burnouts and controls did not differ during pretest. As the day progressed the performance of controls improved more than the performance of burnouts. Moreover, the control group showed a decrease of blood pressure in response to mental task demands, a decrease in respiratory sinus arrhythmia activity, and no change in experienced effort. In the burnout group, no change could be demonstrated in blood pressure, suggesting a sympathetic predominance in the sympathetic-vagal balance. Burnouts experienced an increase in effort and were more tired at the end of the workday. CONCLUSION: Burnouts and healthy controls differ in their pattern of sympathetic-vagal activity only after long-lasting work demands. Findings give limited support to Porges's view that in healthy subjects, the vagal system is more responsive to challenging task situations than in chronically stressed individuals. The distinction between two phases in the burnout on the basis of behavioral and physiological characteristics is discussed.

Concurrent validity of questionnaire and performance-based disability measurements in patients with chronic nonspecific low back pain.

This study aimed to investigate the concurrent validity of two approaches to disability measurement in patients with chronic nonspecific low back pain (CLBP). It was hypothesized that if both are measuring the same construct, the instruments would lead to similar disability results and would correlate strongly (r > 0.75). The study compared the results of self-reported and performance-based measures of disability in 64 consecutive patients with CLBP. Participants mean age was 38.0 years, the mean duration of the current episode of back pain 9.9 months, and 90% were off work due to CLBP. The self-report measures used were: the Roland Disability Questionnaire (Roland); the Oswestry Disability Questionnaire (Oswestry); and the Quebec Back Pain Disability Questionnaire (Quebec). Performance was measured using the Isernhagen Work Systems Functional Capacity Evaluation (FCE). The mean scores from the self-report measure are as follows: Roland 13.5 (scale 0-24), Oswestry 28.2 (scale 0-100), Quebec 37.8 (scale 0-100) consistent with moderate to severe disability. In contrast the results from the performance-based measures suggested that the subjects should be able to work at a physical intensity level of moderate to heavy. Little to moderate correlation was observed between the self-report and performance-based measures (Spearman rank correlations: Roland-FCE (-0.20), p > 0.05; Oswestry-FCE (-0.52), p < 0.01; Quebec-FCE (-0.50), p < 0.01). Results are interpreted to suggest that both performance-based and self-report measures of disability should be used in order to obtain a comprehensive picture of the disability in patients with CLBP.

Prediction of Musculoskeletal Discomfort in a Pick and Place Task (A pilot study).

A pilot study was conducted regarding the effects of working posture, handling frequency, and task duration on musculoskeletal discomfort. Participants rated their discomfort perceived while performing a repetitive task at 8 different combinations of manipulations. Pauses between the work periods lasted 15 min. Discomfort was rated according to Borg's category-ratio scale CR-10 and postures were recorded by an optoelectronic movement registration system. From linear multiple regression analysis equations for predicting discomfort at various body regions were obtained. Coefficients of determination especially point to trunk inclination and handling frequency as major determinants of musculoskeletal discomfort.