Frequency of breaks, amount of muscular rest, and sustained muscle activity related to neck pain in a pooled dataset.

Background: Neck pain remains a persistent challenge in modern society and is frequently encountered across a wide range of occupations, particularly those involving repetitive and monotonous tasks. It might be expected that patterns of trapezius muscle activity at work, characterized by few breaks and prolonged periods of sustained muscle activity, are linked to neck pain. However, previous cross-sectional studies have generally failed to establish a definitive association.

Discrepancies in assessing home care workers' working conditions in a Norwegian home care service: differing views of stakeholders at three organizational levels.

Background: The present study is a follow-up study of factors contributing to an undesirable quality of work environment and sick leave rate in the home care services in a Norwegian municipality. The underlying assumption is that organizational discrepancies in the perceptions and appraisals of significant factors and processes in an organization have detrimental effects on the management of the organization and on work environment conditions. Thus, the study aim is to explore potential organizational discrepancies in the appraisals of factors relating to home care workers' working conditions.

Work demands and health consequences of organizational and technological measures introduced to enhance the quality of home care services--A subgroup analysis.

This study of home care workers in a Norwegian municipality aimed to examine the effect of two measures involving organizational (job checklists) and technological (personal digital assistants) job aids on perceived work demands and musculoskeletal health. Questionnaire data was collected in 2009 (n = 138, response rate 76.2%) and 2011 (n = 80, response rate 54%).

The Response of Denervated Muscle to Long-Term Electrical Stimulation.

Adapted from: Lømo T, Westgaard RH, Hennig R, Gundersen K. The response of denervated muscle to long-term electrical stimulation, In: Carraro U, Angelini C, eds. Proceedings of the First Abano Terme Meeting on Rehabilitation, 1985 August 28-30, Abano Terme, Padova, Italy, An International Symposium, Satellite Meeting of the XIII World Congress of Neurology, Hamburg 1985.

Understanding significant processes during work environment interventions to alleviate time pressure and associated sick leave of home care workers--a case study.

Background: Ergonomic and work stress interventions rarely show long-term positive effect. The municipality participating in this study received orders from the Norwegian Labour Inspectorate due to an identified unhealthy level of time pressure, and responded by effectuating several work environment interventions. The study aim is to identify critical factors in the interaction between work environment interventions and independent rationalization measures in order to understand a potential negative interfering effect from concurrent rationalizations on a comprehensive work environment intervention.

Perceived occupational exposures of home care workers and the association to general tension, shoulder-neck and low back pain.

Background: Home care workers are at risk of various harmful occupational exposures, health complaints and sick leave.

Objective: Identifying occupational exposures related to shoulder-neck and low back pain, and assessing the comparative importance of such exposures, for home care workers.

Methods: One hundred and thirty-eight home care workers in a large municipality in Norway participated in the study (response rate 76.

Trapezius activity of fibromyalgia patients is enhanced in stressful situations, but is similar to healthy controls in a quiet naturalistic setting: a case-control study.

Background: Muscle activity and pain development of fibromyalgia (FM) patients in response to mental stress show inconsistent results, when compared to healthy controls (HCs). A possible reason for the inconsistent results is the large variation in stress exposures in different studies. This study compares muscle responses of FM patients and HCs for different modes and levels of imposed stress, to elucidate features in stress exposures that distinguish stress responses of FM patients from HCs.

Heart rate variability in fibromyalgia patients and healthy controls during non-REM and REM sleep: a case-control study.

Objectives: To investigate heart rate variability (HRV) in fibromyalgia (FM) patients and healthy controls (HCs) during different sleep stages, and to examine the association of HRV with pain and sleep quality.

Method: Polysomnography was recorded from 23 female FM patients and 22 age- and sex-matched HCs. HRV was recorded from bedtime until awakening including the standard deviation of normal-to-normal intervals (SDNN), the root mean square successive difference (RMSSD), and the low (LF; 0.

Catecholamines and heart rate in female fibromyalgia patients.

Background: Fibromyalgia syndrome is a disease of unknown pathogenesis characterised by widespread chronic musculoskeletal pain. Fibromyalgia has been associated with dysregulation of the stress systems, but results are inconsistent.

Purpose: To investigate autonomic nervous system activity (urinary noradrenaline, adrenaline, dopamine, and heart rate) of fibromyalgia patients and healthy controls.

Comparison of the cortisol awakening response in women with shoulder and neck pain and women with fibromyalgia.

Shoulder and neck pain (SNP) and fibromyalgia syndrome (FMS), two musculoskeletal conditions of unknown pathogenesis, share some common features in terms of altered neuroendocrine responses, pain and stress perception. However, the pain distribution in SNP is localized, whereas in FMS is more widespread. Because regional musculoskeletal pain may represent an intermediate stage along a continuum towards widespread musculoskeletal pain we compared the cortisol awakening response (CAR) in women with SNP with the CAR in FMS patients and healthy controls (HC) in a controlled hospital-hotel setting.

Occupational musculoskeletal and mental health: Significance of rationalization and opportunities to create sustainable production systems - A systematic review.

This literature review aims to identify occupational musculoskeletal and mental health effects of production system rationalization as well as organizational-level measures that may improve health outcome ("modifiers" in this review). A short review of the effect of ergonomic interventions is included as background and rationalization is discussed as a theoretical concept. Indicator variables for occupational musculoskeletal and mental health and related risk factors are presented.

Fibromyalgia syndrome is associated with hypocortisolism.

Background: Fibromyalgia syndrome (FMS) is a disease of unknown pathogenesis characterized by chronic musculoskeletal pain. FMS has been also associated with altered endocrinological responses, but findings are inconsistent.

Purpose: The aim of the present study was to investigate free salivary cortisol levels in FMS patients compared with healthy controls with a particular focus on the cortisol awakening response (CAR).

Systematic evaluation of observational methods assessing biomechanical exposures at work.

Objectives: This systematic review aimed to identify published observational methods assessing biomechanical exposures in occupational settings and evaluate them with reference to the needs of different users.

Methods: We searched scientific databases and the internet for material from 1965 to September 2008. Methods were included if they were primarily based on the systematic observation of work, the observation target was the human body, and the method was clearly described in the literature.

Back posture and low back muscle activity in female computer workers: a field study.

Background: Few studies have investigated sitting posture and low back muscle activity in occupational settings. This study aims to determine back posture and its influence on low back muscle activity in computer workers, and to investigate whether the work situation is associated with exacerbation of low back pain.

Methods: Twenty-one female computer workers participated.

Similarities in stress physiology among patients with chronic pain and headache disorders: evidence for a common pathophysiological mechanism?

One common feature of chronic musculoskeletal pain and headaches are that they are both influenced by stress. Among these, tension-type headache (TTH), fibromyalgia (FMS) and chronic shoulder/neck pain (SNP) appear to have several similarities, both with regard to pathophysiology, clinical features and demographics. The main hypothesis of the present study was that patients with chronic pain (TTH, FMS and SNP) had stress-induced features distinguishing them from migraine patients and healthy controls.

A unilateral sympathetic blockade does not affect stress-related pain and muscle activity in patients with chronic musculoskeletal pain.

Objective: Chronic musculoskeletal pain is often exacerbated by mental and social stress. The association between stress and musculoskeletal pain is potentially mediated by peripheral sympathetic nerves, either directly or indirectly through muscle activity. In the present study we wanted to determine whether sympathetic blockade could affect either the pain or the muscular activity experienced during mental stress in patients with chronic musculoskeletal pain.

Autonomic and muscular responses and recovery to one-hour laboratory mental stress in healthy subjects.

Background: Stress is a risk factor for musculoskeletal pain. We wanted to explore stress related physiology in healthy subjects in order to gain insight into mechanisms of pain development which may relate to the pathophysiology of musculoskeletal pain disorders.

Methods: Continuous blood pressure, heart rate, finger skin blood flow, respiration, surface electromyography together with perception of pain, fatigue and tension were recorded on 35 healthy women and 9 healthy men before, during a 60 minute period with task-related low-grade mental stress, and in the following 30 minute rest period.

Cardiovascular responses to cognitive stress in patients with migraine and tension-type headache.

Background: The purpose of this study was to investigate the temporal relationship between autonomic changes and pain activation in migraine and tension-type headache induced by stress in a model relevant for everyday office-work.

Methods: We measured pain, blood pressure (BP), heart rate (HR) and skin blood flow (BF) during and after controlled low-grade cognitive stress in 22 migraineurs during headache-free periods, 18 patients with tension-type headache (TTH) and 44 healthy controls. The stress lasted for one hour and was followed by 30 minutes of relaxation.

The influence of body posture, arm movement, and work stress on trapezius activity during computer work.

The study aimed to determine the influence of arm posture and movement on trapezius activity of computer workers, considering the full workday. A second aim was to investigate if work periods perceived as stressful were associated with elevated or more sustained muscle activity pattern. Twenty-six computer workers performing call-center (n=11), help desk (n=7), or secretarial (n=8) work tasks participated.

Noradrenaline and cortisol changes in response to low-grade cognitive stress differ in migraine and tension-type headache.

The goal of this study was to explore the relationship between indicators of sympathoneural, sympathomedullar and hypothalamic-pituitary-adrenocortical (HPA) activity and stress-induced head and shoulder-neck pain in patients with migraine or tension-type headache (TTH). We measured noradrenaline, adrenaline and cortisol levels before and after low-grade cognitive stress in 21 migraineurs, 16 TTH patients and 34 controls. The stressor lasted for 60 min and was followed by 30 min of relaxation.

Autonomic activation and pain in response to low-grade mental stress in fibromyalgia and shoulder/neck pain patients.

Objective: Psychosocial stress is a risk factor for musculoskeletal pain, but how stress affects musculoskeletal pain is poorly understood. We wanted to examine the relationship between low-grade autonomic activation and stress-related pain in patients with fibromyalgia and localised chronic shoulder/neck pain.

Methods: Twenty-three female patients with fibromyalgia, 29 female patients with chronic shoulder-neck pain, and 35 healthy women performed a stressful task lasting 60min.

Respiratory and stress-induced activation of low-threshold motor units in the human trapezius muscle.

The study aimed to characterize trapezius motor unit firing pattern in low-amplitude contractions, with emphasis on respiratory modulated activity. Constant-amplitude contractions with shoulder elevation, controlled by feedback of the root mean square detected surface electromyographic (SEMG) signal, typing with arm movement and tasks with mental stress were performed. Single motor unit activity was recorded by a quadrifilar fine-wire electrode.

Stress-induced pain and muscle activity in patients with migraine and tension-type headache.

We recorded deep pain and surface electromyographic (EMG) responses to stress in 22 migraineurs during headache-free periods, 18 patients with tension-type headache (TTH), and 44 healthy controls. Sixty minutes of cognitive stress was followed by 30 min relaxation. EMG and pain (visual analogue scale) in the trapezius, neck (splenius), temporalis and frontalis areas were recorded.