Cecilie Røe

Variation in reporting of pain and other subjective health complaints in a working population and limitations of single sample measurements.

&NA; Measuring health complaints by administrating a single report is common. Our aim was to assess variation in pain and other subjective complaints over an extended period, whether a single‐sample produces representative data, and determine associations between complaints. Health‐complaint reports were collected from postal workers at monthly intervals over a period of 32–34 consecutive months (1997–2000). We computed six compound complaint‐severity indices of 30 complaint‐severity scores (intensity score×duration score, scale 0–9). In 67% of the scores, the complaints exhibited larger deviation from a reference (12 consecutive reports in the last 24 months of the study period) when using one report from the respective reference period compared with the mean of two consecutive reports. Four consecutive samples were needed to obtain agreement for 95% of the data when the criterion of accepted deviation from the reference was set to ±1.0. Neither inspection of graphs nor statistical tests revealed any seasonal pattern or trend on either a group or individual level. The musculoskeletal and psychological complaint‐severity indices correlated strongly (rs>0.66). Correlations between the different somatic indices were generally weak or moderate (rs<0.55). The initial report produced higher complaint ratings than subsequent reports did. Due to large intra‐individual complaint variability and higher complaint‐severity level exhibited on the initial report compared to those that followed, measuring subjective health with a single‐sample approach does not produce data representativeness for average complaints over a period. More than two samples should be collected when the purpose is to reveal changes in health.

Attenuated adrenergic responses to exercise in women with fibromyalgia--a controlled study.

The pathogenesis of widespread pain and fibromyalgia (FM) is unknown. Altered responses from the hypothalamus–pituitary–adrenal axis, sympathetic nervous system and muscular system have been suggested as being of importance. The present study was undertaken to determine: (i) whether the sympathoadrenal response to repetitive isometric contractions until exhaustion is altered in patients with FM, and (ii) whether sympathoadrenal responses are associated with muscle fatigue and pain during exercise.

Cognitive performance and muscle activation in workers with chronic shoulder myalgia

The present study determined whether workers with chronic shoulder myalgia exhibit impaired cognitive performance and elevated muscle activation. Ten workers with and 10 without shoulder myalgia performed three sessions, each consisting of three different cognitive tasks. Subjective pain was reported on visual analogue scales (VAS). Surface electromyography was recorded bilaterally from the trapezius and forearm extensor muscles. Speed and error rates of the cognitive work were almost the same in the two groups, but the myalgia subjects reported more stress during the work. In two of the cognitive tasks, both groups increased their speed of performance to the same extent from the first to the third session, despite pain increase in the myalgia subjects. In the biomechanically demanding task, the speed fell from the first to the third session in both groups. Muscle activation was equal in the two groups and constant throughout the protocol despite changes in speed of performance and pain. It is concluded that localized chronic muscle pain does not significantly alter cognitive performance, or muscle activation level during cognitive work. However, the perceived burden of work is larger, as indicated by the higher stress reported during cognitive work in the myalgia subjects compared with their pain-free controls.

Muscle activity and blood flux during standardised data-terminal work

Abstract To determine the effects of computer work on muscle microcirculation, blood flux was recorded by laser-Doppler from the upper trapezius muscle, during and after standardised data-terminal work with variable time- and precision demands. Fourteen subjects, mean age 39 years (range 22–66 years), performed nine trials of tracking with three levels of time pressure and three widths of the tracks, and a complex reaction-time task. Mean arterial pressure, heart rate and electromyography from the forearm and shoulder muscles were measured. Blood fluxes increased during the tracking. In spite of the very low muscle activity required to perform the tracking, a marked hyperemia was observed after cessation of tracking. This response may be a mechanism for pain during and after computer work. There were, however, large inter-individual variations in the blood-flux responses to tracking, and laser-Doppler measurements need to be compared with other methods in humans. Relevance to industry The present study shows that it is possible to measure microcirculation in the upper trapezius during tasks that model computer work. The increased blood flow observed after computer work of short duration with very low muscle activity may be of importance for pain during this type of work.

Muscle activation in the contralateral passive shoulder during isometric shoulder abduction in patients with unilateral shoulder pain

Studies have shown an increased muscle activation at the opposite passive side during unilateral contractions. The purpose of the present study was to examine the influence of pain on muscle activation in the passive shoulder during unilateral shoulder abduction. Ten patients with unilateral rotator tendinosis of the shoulder and nine healthy controls performed unilateral maximal voluntary contractions (MVC) and sustained submaximal contractions with and without subacromial injections of local anaesthetics of the afflicted shoulder. Muscle activation was recorded by electromyography (EMG) from the trapezius, deltoid, infraspinatus and supraspinatus muscles in both shoulders. During MVCs, the EMG amplitude from muscles of the passive afflicted side was not different in patients and controls, and was not influenced by pain alterations. In contrast, the EMG amplitude from the muscles of the passive unafflicted side was lower in the patients and increased after pain reduction. During the sustained submaximal contraction the EMG amplitude increased gradually in the passive shoulder to 15-30% of the EMG amplitude observed during MVC. This response was not influenced by differences in pain. We conclude that muscle activation of the passive shoulder was closely related to the activation of the contracting muscles and thus related to central motor drive, and not directly influenced by changes in pain.

Pain and Sympathoadrenal Responses to Dynamic Exercise in Women with the Fibromyalgia Syndrome

Objectives: To determine whether sympathoadrenal responses during exhaustive bicycling is attenuated in fibromyalgia syndrome [FMS] patients compared to demographically matched healthy normal control [HNC] subjects, and whether pain during exercise is related to sympathoadrenal responses. Another objective was to determine whether exercise exacerbates pain and fatigue in the subsequent days. Methods: Thirty women [15 FMS, 15 HNC] women matched for age, exercise frequency, and smoking habits bicycled with a stepwise increment in workload until exhaustion. Heart rate, oxygen uptake, and plasma catecholamine concentrations were determined before, during, and after exercise. Pain and perceived exertion were recorded during exercise. Average pain, sleep disturbance, and fatigue were recorded for the seven days preceding the exercise and for Day 1 and Day 7 after the exercise. Results: Plasma catecholamine concentrations, heart-rate, and oxygen uptake increased similarly during exercise in FMS patients and controls. By contrast, the oxygen uptake at exhaustion was significantly lower in the FMS group. However, when the FMS and HNC subjects were re-matched according to peak oxygen uptake, there were still no significant differences in biological responses were found. Pain increased substantially during exercise in the FMS group. Despite that, no increase in pain or fatigue was observed in the days following exercise. Conclusion: The FMS patients were less physically fit than the HNCs. The catecholamine and heart rate responses during dynamic exercise were normal in the FMS patients. However, the increase in exercise-induced pain reported in the FMS group could not be explained by an attenuated catecholamine response. Exhaustive dynamic exercise did not induce increased pain or fatigue in patients with FMS.