| 1. |
- Aasa, Ulrika, et al.
(författare)
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Stress monitoring of ambulance personnel during work and leisure time
- 2006
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Ingår i: International Archives of Occupational and Environmental Health. - : Springer Science and Business Media LLC. - 0340-0131 .- 1432-1246. ; 80:1, s. 51-59
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Tidskriftsartikel (refereegranskat)abstract
- Objectives: The aim of the present study was to assess physiological and subjective stress markers during a 24-h ambulance work shift and during the next two work-free days, and relate these parameters to self-reported health complaints. Methods: Twenty-six ambulance personnel were followed during a 24-h work shift and during the next two work-free days with electrocardiogram, cortisol assessments and diary notes. The ambulance personnel also performed tests of autonomic reactivity before and at the end of the work shift. The subjects were categorized into two groups according to their number of health complaints. Results: In general, stress markers did not show differences between the work shift and leisure time. However, a modest deviation in heart rate variability pattern and higher morning cortisol values during work in comparison with work-free days were observed in personnel with many health complaints. Conclusions: Subjective and physiological characteristics of ambulance personnel did not indicate distinctive stress during the 24-h work shift. Relationships between frequent health complaints and specific work-related factors require further prospective studies.
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| 2. |
- Kalezic, Nebojsa
(författare)
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Autonomic reactivity in muscle pain : clinical and experimental assessment
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There are numerous indications of possible involvement of the autonomic nervous system in the genesis of chronic pain. The possibility exists that sympathetic activation is related to motor dysfunction and changes in sensory processing, which have otherwise been implicated in musculoskeletal disorders.The primary aim of the thesis has been to investigate autonomic regulation at rest and in response to laboratory tests of autonomic function in subjects suffering from chronic pain in different localisations (lower back, neck-shoulder and neck-jaw), as well as to study the relations between autonomic regulation, proprioceptive acuity and clinical data. Secondary aim has been to assess autonomic regulation in fit, pain-free subjects in response to experimentally induced pain and in occupationally relevant settings.A total of 194 subjects suffering from chronic pain participated [low back pain (LBP) n=93; non-traumatic neck pain (NT) n=40, Whiplash associated disorder (WAD) n=40, Whiplash with temporomandibular dysfunction (WADj) n=21]. Each chronic pain group was subjected to a battery of autonomic function tests combining cognitive (Stroop Colour-Word conflict tests), physical (handgrip), sensory (unpleasant sound) and motor tasks (chewing tests) as well as the activation of reflex pathways (paced breathing and the orthostatic test) and compared to an age- and gender balanced control group. Autonomic regulation was also assessed in exposure to experimentally induced muscle pain in healthy subjects (n=24) in order to describe acute pain reaction. Further assessment was carried out during monotonous repetitive work and dynamic work in healthy subjects (n=10) and in a three-day monitoring of ambulance personnel (n=26) in occupational settings.Autonomic regulation was evaluated using cardiovascular (heart rate and heart rate variability, local blood flow and blood pressure), respiratory (breathing rate) electrodermal (skin conductance), muscular (trapezius and masseter EMG) and biochemical (insulin, cortisol, catecholamines) variables. Proprioceptive acuity was assessed using active-active repositioning tests. Pain levels were assessed using Visual-analogue or Numerical Rating scales. General health was evaluated through the Short-Form SF-36 Health Related Quality of Life questionnaire and Self-Efficacy Score questionnaires, whereas dysfunction was evaluated using the Oswestry Low Back Pain questionnaire, Pain Disability and Neck Disability Index questionnaires, the McKenzie evaluation and primary healthcare diagnoses. Self-reports of pain, stress and exertion were acquired prior to, during and post-testing.Chronic pain subjects were characterised by increased sympathetic and decreased parasympathetic activity as reflected in heart rate (LBP, WAD, WADj), heart rate variability (LBP, WAD, WADj), blood pressure (WADj) and electrodermal activity (LBP). In general, WAD showed more pain and dysfunction than NT, with lower self-efficacy and health-related quality of life. Differential reactivity was observed only in WAD, with increased responsiveness to sensory stimuli (heart rate variability, electrodermal activity), and motor tasks (heart rate) and a decreased response to cognitive challenge (heart rate variability, electrodermal activity). A significant part of WADj subjects showed sensorimotor impairment and low endurance in chewing tests, concomitant with a cardiovascular response that correlated with pain levels. Proprioceptive acuity was not found to be impaired among subjects suffering from chronic pain, and there were no indications of significant individual response specificity. Response to experimentally induced muscle pain in healthy subjects was also characterised by a prominent cardiovascular component. In simulated occupational settings autonomic activation and transient insulin resistance were detected in healthy subjects following monotonous repetitive work, with no similar effects following dynamic exercise. Modest deviations in circadian heart rate variability patterns during workdays were detected in ambulance personnel reporting more pronounced musculoskeletal symptoms, with no such effects on work-free days.Autonomic balance observed in chronic pain subjects was characterised by a trend towards increased sympathetic activity in comparison with pain-free controls. Moderate signs of affected reactivity to autonomic function tests were observed in patients with WAD, however no specific reaction patterns have been observed in any chronic pain group. Correspondence between the intensity of pain and autonomic activity was observed in acute pain and in chronic pain groups characterised by higher pain levels. As indicated by autonomic and neurohormonal changes in the recovery from real and simulated work, further studies with physiological monitoring of the effects of work-related stress are warranted for better understanding of the mechanism of musculoskeletal disorders.
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| 3. |
- Wilén, Jonna, et al.
(författare)
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Psychophysiological tests and provocation of subjects with mobile phone related symptoms
- 2006
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Ingår i: Bioelectromagnetics. - : Wiley. - 0197-8462 .- 1521-186X. ; 27:3, s. 204-214
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to investigate the effect of exposure to a mobile phone-like radiofrequency (RF) electromagnetic field on persons experiencing subjective symptoms when using mobile phones (MP). Twenty subjects with MP-related symptoms were recruited and matched with 20 controls without MP-related symptoms. Each subject participated in two experimental sessions, one with true exposure and one with sham exposure, in random order. In the true exposure condition, the test subjects were exposed for 30 min to an RF field generating a maximum SAR(1g) in the head of 1 W/kg through an indoor base station antenna attached to a 900 MHz GSM MP. The following physiological and cognitive parameters were measured during the experiment: heart rate and heart rate variability (HRV), respiration, local blood flow, electrodermal activity, critical flicker fusion threshold (CFFT), short-term memory, and reaction time. No significant differences related to RF exposure conditions were detected. Also no differences in baseline data were found between subject groups, except for the reaction time, which was significantly longer among the cases than among the controls the first time the test was performed. This difference disappeared when the test was repeated. However, the cases differed significantly from the controls with respect to HRV as measured in the frequency domain. The cases displayed a shift in low/high frequency ratio towards a sympathetic dominance in the autonomous nervous system during the CFFT and memory tests, regardless of exposure condition. This might be interpreted as a sign of differences in the autonomous nervous system regulation between persons with MP related subjective symptoms and persons with no such symptoms.
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