DOES REPETITIVE WORK CAUSE SYMPTOMS OF STRESS?

Pain in the upper limb is common in repetitive work, perhaps because of physical factors but also, potentially, through psychological mechanisms that evoke physiological responses or modify perceptions and disability behaviour. Bonde et al1 have examined the hypothesis that a direct pathway extends from physical stresses through to psychological reaction. They reason that in this case shorter task cycle times and highly repetitive movements should predict the onset of stress related symptoms. In fact, they failed to find this when a cohort of 2846 workers were followed up over three years and repeatedly assessed using a stress inventory. A particular strength of the study was the careful quantification of physical exposures using video recordings. This enabled estimates to be made of cycle times, periods in which repetitive work was performed, and the frequency of wrist movements. The odds ratios in high versus low exposure categories were close to unity (both for prevalent stress symptoms at baseline and for incident symptoms during follow up), and provided no support for the hypothesis being tested. PHYSICAL ACTIVITIES AND ATRIAL DYSRHYTHMIAS Endurance sports have been linked with a greater risk of atrial fibrillation, but it seems the same is not true of physical activity at work. Until now the relation has gone unexplored, but Frost et al2 followed a cohort of 38 400 adults aged 50–65 years in 1993–2001 and linked them to hospital discharge diagnoses of atrial fibrillation or flutter. Cohort members ’ work was categorised as sedentary, light, or heavy using a self-completed questionnaire about occupational activity in the previous year. Hazard ratios were estimated using a proportional hazards model with adjustment for blood pressure, cholesterol, body mass index, and various other factors. Among the study’s strengths were the large number of cases in the cohort (over 400 admissions for atrial dysrhythmia were identified), detailed information on confounders, and complete follow up through nationwide data linkage. Reassuringly, risks did not vary systematically by physical workload