Psychophysiological mechanisms of pain in computer work: the blood vessel-nociceptor interaction hypothesis

Almost all hypotheses of muscle pain maintain that the pain results from muscle cell activation. The mechanisms so far proposed for the generation of pain are related to hypoxia, effects of energy deficit, or intracellular calcium accumulation, leading to muscle cell damage. However, it has not been possible to find reliable causal associations between pain and muscle activation as measured by electromyography (EMG). Explanations of the pathogenesis of pain have to account for the activation of sensory nerves that mediate information of potential tissue injury to the nerve system, the nociceptors. The finding that sustained activation of low-threshold motor units occur in computer work (the 'Cinderella hypothesis') does not explain the genesis of muscle pain. There is a paucity of reliable evidence of associations between muscle cell damage and work-related muscle pain. Some of the available data indicate that muscle fibre activity may be a consequence of pain rather than a cause. A hypothesis pertaining to work situations with cognitive tasks and low-level muscle activity is presented. This hypothesis proposes that muscle pain originates from the blood vessel-nociceptor interactions of the connective tissue of the muscle. Possible candidate mediators are discussed.     

The nature of labour pain: An updated review of the literature

Background

The pain experience associated with labour is complex. Literature indicates psychosocial and environmental determinants of labour pain, and yet methods to support women usually target physiological attributes via pharmacological interventions.

Sterile water injections for childbirth pain: An evidenced based guide to practice

Background

About 30% of women in labour suffer from lower back pain. Studies of sterile water injections for management of low back pain have consistently shown this approach to be effective. The objective of this evidence-based guide is to facilitate the clinical use of sterile water injections to relieve lower back pain in labouring women.

Changes in foot posture during pregnancy and their relation with musculoskeletal pain: A longitudinal cohort study

Aim

To examine foot posture changes during the three trimesters of pregnancy and to determine whether there is a relationship between these changes and the pain experienced in this period.

Predictors of women’s positive childbirth pain experience: Findings from an Icelandic national study

Background

Pain in childbirth has been identified as one of the major components in the childbirth experience and an important topic that needs to be addressed during pregnancy, birth and the after-birth period.

Chronic strain, daily work stress and pain among workers with rheumatoid arthritis: Does job stress make a bad day worse?

The structure of the job and the daily experience of work are challenges for workers with rheumatoid arthritis. Yet little is known about how these two factors interact to put workers with chronic pain at risk for worse pain on a given day. This exploratory 20 workday diary study of 27 workers with rheumatoid arthritis used hierarchical linear modelling to examine how the structure of the job and neuroticism moderate the relationship between daily undesirable work events (daily stressors), and pain reports within a day. On days with more undesirable work events compared to days with fewer events, individuals with jobs associated with job 'strain' (high demand/low control) reported greater midday pain, irrespective of neuroticism and negative mood, than workers with other combinations of demand and control. These findings demonstrate the utility of analysing fluctuating within-person relationships among pain, mood and daily work stressors within the context of the structure of the job, and helps to explain why daily work stressors result in worse health outcomes for some but not all workers with RA.     

Occupational overuse syndrome and the effects of psychosocial stressors on keyboard users in the newspaper industry

There is continuing concern about the incidence of occupational overuse syndrome (OOS) among workers using keyboards. Following results from research showing positive correlations between psychosocial factors in the workplace and the incidence of OOS symptoms, it was hypothesizcd that differences in rates of pain reporting by keyboard workers are related to job stress caused by different levels in thc quality of the psychosocial work environment. An interaction between autonomy and the impact of work pressure on pain reporting was also predicted. Data were used from a sample of 550 keyboard users in several different types of job, working in eight different newspaper offices of the same newspaper company. The results confirmed the hypotheses. Post hoc analysis showed that there were important differences between the types of stressors that predicted the reporting of pain between offices, and those that predicted pain reporting between types of job. These results confirm the importance of considering psychosocial factors in work and workplace design in connection with the prevention of OOS. Conclusions are also drawn about the situation specificity of such empirical research, and the need for more theoretical work in the search for the aetiology of OOS.     

论老庄哲学的生命智慧

在老庄看来,人的生命以“道”为根源,由“道”到“气”演化出人生命的自然之性,而现实中人又承受着社会的樊笼、难名的孤独、外在的诱惑、死亡的阴影等诸多痛苦,所以人们要贵生、顺生、柔弱不争、少私寡欲、逍遥无待来养护生命,故老庄关于人之生命的终极关怀,在今天社会显得尤为珍贵。     

Intradermal sterile water injections for the relief of low back pain in labour -- a systematic review of the literature

OBJECTIVE: To search literature published on the administration of intradermal sterile water injections to women in labour who experience severe low back pain, and to critically evaluate the evidence for therapeutic merit. METHOD: A systematic review of six randomised controlled trials from countries including Canada, Denmark, Iran, Sweden and Thailand was conducted. RESULTS: Statistically significant findings (p<0.0001) of relief of low back pain in labour lasting from 10 min to 2 h post-administration. CONCLUSION: Intradermal injections of sterile water possess powerful analgesic benefits for women experiencing low back pain in labour and their use in this therapeutic setting is justifiable.     

Parents’ Interpersonal Distance and Touch Behavior and Child Pain and Distress during Painful Pediatric Oncology Procedures

Children with cancer and their parents report that treatment-related procedures are more traumatic and painful than cancer itself. Competing hypotheses have emerged regarding relations between parents’ social support and child pain and distress. Little is known about caregivers’ use of nonverbal immediacy behaviors that may function as social support messages. This study describes caregivers’ interpersonal distance and touch behaviors during painful pediatric oncology procedures and examines relations between those behaviors and children’s pain and distress. Caregivers’ total touch time and instrumental (task-oriented) touch time, but not supportive touch time, during the actual procedure covaried with children’s procedural pain and distress. This research was conducted as part of a larger investigation funded by a grant from the National Cancer Institute, “Parental Role in Pediatric Cancer Pain and Survivorship” (NCI R01 CA100027), Terrance L. Albrecht, PI. The authors wish to thank Ellen Jones for her efforts.