The effect of pain reduction on perceived tension and EMG-recorded trapezius muscle activity in workers with shoulder and neck pain

The study was initiated to evaluate the effect of pain-reducing therapies on factors previously associated with work-related shoulder and neck pain, namely increased muscle activity in the upper trapezius and perceived general tension. Thirty-three women in three groups were assessed before and after an intervention period and by questionnaire 6 months later. The purpose of this study was primarily to investigate associations between upper trapezius muscle activity, perceived general tension and pain, and secondly, to compare effects of individually based physiotherapy and group exercise for workers with shoulder and neck myalgia. All three groups reported a significant alleviation of pain and perceived general tension, while the electromyographically (EMG) recorded upper trapezius muscle activity level remained unchanged or increased. Improvements were similar in all three treatment groups, but individual-based therapies were rated more beneficial on subjective measures. Significant correlation was found between pain and perceived general tension (r = 0.66, p <0.01), while there was no correlation between pain or perceived general tension and recorded muscle activity.     

Positioning for clinical dental hygiene care. Preventing back, neck and shoulder pain

Spasmodic dysphonia is a focal dystonia that effects the proximal muscles (adduction dystonia) or dilatory (abduction dystonia) of the larynx. Botulinum toxin (BTX), generally delivered by percutaneous injection, is the treatment of choice. Recently, use has been made of a transoral route of delivery, with BTX injected through a curved device with visual control. It remains to be determined which route is better. Percutaneous injection is simple and well-tolerated, but the transoral route is theoretically more effective. We assessed the efficacy of both techniques in 19 patients with adduction dystonia, conducting 55 treatment sessions by percutaneous injection and 20 by transoral injection. All the transoral treatments were effective (20/20, 100%), but only 81% (45-155) of the percutaneous treatments were (p < 0.05). Two patients who had doubtful responses after percutaneous delivery improved considerably when the transoral approach was used. In spite of its greater complexity, the transoral approach is probably more effective than the percutaneous route. We describe a curved device for transoral injection that is composed of simple elements available at any health center.     

Relationship between sleep, neck muscle activity, and pain in cervical dystonia

Deficit in active and inhibitory avoidance behaviour has been pentylenetetrazole (PTZ)-kindled rats. This supports the view that memory deficit is an integral part of epilepsy. In the present study we examined the effect of the nootropic drugs piracetam and fipexide on memory deficit induced by PTZ-kindling in shuttle-box- and step-down-trained rats. The retention in piracetam- and fipexide-treated animals was significantly improved compared to the kindled controls. The mechanisms of action of the two drugs are considered. The favourable of nootropic drugs in cases of amnesia provoked by PTZ-kindling might be of interest in clinical practice.     

Psychophysiological treatment of migraine and tension headaches: A 12-month follow-up.

Conducted a 12-mo follow-up of the present authors' (1983) study population of chronic headache sufferers by telephone interviewing 31 chronic migraine and 25 chronic tension headache patients (aged 18–61 yrs) who had been treated with EMG, muscle relaxation, and fingertip temperature training to test a hypothesis of biofeedback placebo effects. A previous 3-mo follow-up had revealed that all treatments had produced significant improvement, and relaxation was not as good as the biofeedback devices for obtaining a reduction in monthly headache hours. At 12-mo follow-up, the 3-mo improvement was sustained overall, but migraineurs as a group appeared to regress slightly, while tension patients improved significantly in the interim. On the basis of a 50% reduction in symptomatology, biofeedback treatment was significantly superior to relaxation for tension headaches, although this had not been true at the 3-mo assessment. Temperature training was at least as effective as EMG for both headache groups. In view of these results, biofeedback treatment is viewed less as placebo administration and more as a secondary reinforcer of a specific but unknown physiological response. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Job stress in midlife working women: Relationships among personality type, job characteristics, and job tension.

Investigated the relationships among midlife working women's Type A (coronary prone) personality, perceived job characteristics, and feelings of job tension. The Women's Work Questionnaire was administered to 161 35–55 yr old females who were employed by a large state social service agency. The questionnaire, developed for the present study, comprises sections for demographic and job-related information, the Sales Type A Personality Index—Short Form, the Job Characteristics Inventory, and the Job-Related Tension Index. Multiple regression analyses revealed a significant relationship between job tension and a linear combination of Type A personality and job characteristics (i.e., autonomy, feedback, significance, friendship opportunities, variety, challenge, identity, dealing with others). There were also significant relationships between job tension and the following variables considered singularly: Type A personality, autonomy, feedback, significance, and friendship opportunities. Results support a person–environment fit approach to the study, prevention, and remediation of job stress. (80 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychophysiological stress reactions in female and male urban bus drivers.

Male and female urban bus drivers were studied at work during everyday bus driving in urban traffic (work condition) and watching educational programs (comparison condition). The results showed that (a) both sexes had significantly higher adrenaline, noradrenaline, and cortisol excretion levels during work than during the comparison session; (b) during work and inactivity, there were no significant sex differences in hormone excretion for either hormone; (c) the percentage increase during work compared with control levels for all hormones was equally high in the female group as in the male group; and (d) there were no significant sex differences in self-reported mood (distress, well-being, control) during bus driving. The results are discussed in terms of type and intensity of stressors, gender differences in costs of adaptation, preventive measures, and the role of social influences in psychoneuroendocrine regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Load pattern and pressure pain threshold in the upper trapezius muscle and psychosocial factors in medical secretaries with and without shoulder/neck disorders

OBJECT: A current hypothesis for the genesis of muscular complaints in the shoulder/neck region postulates that short periods with a completely relaxed muscle are essential to avoid complaints. Another hypothesis is that these disorders are related to psychosocial conditions at work. In order to test these hypotheses, 23 medical secretaries were investigated. METHODS: The load pattern during work in the upper trapezius muscle bilaterally was assessed with electromyographic (EMG) technique and exposure variation analysis (EVA). In addition, pressure pain threshold (PPT) was measured on the trapezius muscle bilaterally and on the sternum. Psychosocial conditions at work were assessed with a questionnaire. RESULTS: The medical secretaries with complaints had significantly fewer episodes with totally or close to totally relaxed muscle compared with the healthy group. The group with complaints tended to have a more monotonous load pattern at low levels (approx. 1%-5% maximum voluntary contraction) while the healthy group had more frequent pauses but also somewhat more frequent short load peaks. The group with complaints showed lower PPT readings compared with the healthy group. However, the whole group had considerably lower PPTs than is usually reported in the literature. Of the 12 questions in the psychosocial questionnaire only one regarding work task satisfaction showed a significant difference between the two groups. CONCLUSION: Support is found for hypothesis that secretaries without complaints have more frequent episodes with totally relaxed muscle. A significant difference is found regarding work task satisfaction.     

Personality, anxiety, and muscle tension as determinants of response stereotypy.

"The stereotypy and bias with which Ss used the number series 1-11 in a pseudo-ESP experiment was determined under three experimental conditions: (a) experimentally induced anxiety, (b) experimentally induced muscular tension, and (c) a control condition." Ss scoring in the highest and lowest quartile of the MMPI psychasthenia scale were used. "Under the control condition, the high group was found to be more stereotyped and predictable in their use of the number responses, but under the anxiety and muscle tension conditions this relationship was reversed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Discrimination, dispositions, and cardiovascular responses to stress.

Objective: Recent research suggests that past exposure to discrimination may influence perceptions of, and physiological responses to, new challenges. The authors examined how race and trait levels of hostility and optimism interact with past exposure to discrimination to predict physiological reactivity and recovery during an anger recall task. Design: A community sample of 165 normotensive Black and White adults participated in an anger recall task while having their cardiovascular function monitored. Main Outcome Measures: Blood pressure and heart rate indicators of physiological reactivity and recovery. Results and Conclusion: Participants had higher reactivity and slower recovery to the anger recall task when they had high past discrimination, low cynicism, or high optimism. The pattern of effects was similar for both racial groups, but Blacks had more acute reactivity and slower recovery than Whites. These results are consistent with the perspective of discrimination as a chronic stressor that is related to acute stress responses, particularly for Blacks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low prevalences of chronic widespread pain and shoulder disorders among the Pima Indians

OBJECTIVE: To establish the prevalence of shoulder disease and chronic widespread pain in Pima Indians. METHODS: Cross sectional analyses of data from 4230 subjects for shoulder disease and 105 subjects for chronic widespread pain participating in population surveys RESULTS: The prevalence of shoulder disease was 4.4% (95% CI, 3.8-5.1), age-sex adjusted to the 1980 US census population. This is lower than in a study of Caucasians [prevalence ratio (PR) = 0.29, 95% CI, 0.20-0.42 for men and PR = 0.55, 95% CI, 0.41-0.73 for women]. Shoulder disease was associated with non-insulin-dependent diabetes mellitus (PR = 1.67, 95% CI, 1.19-2.36). No chronic widespread pain was identified (95% CI, 0-3.5%). CONCLUSION: Prevalence of these pain syndromes in Pima Indians is lower than in predominantly Caucasian populations. These findings suggest that these populations have different pain perception or different patterns of risk factors for these disorders.     

Mental stress of long duration: EMG activity, perceived tension, fatigue, and pain development in pain-free subjects

The study examined the relationship between pain development in the shoulder, neck, and facial regions and the EMG activity of underlying muscles, during prolonged exposure to a mental stressor. The subjective perception of tension and fatigue was recorded. Thirty-six subjects were exposed to a two-choice reaction-time test for 1 hour. Electromyographic (EMG) recordings were performed bilaterally over the frontalis, temporalis, splenius, and trapezius muscles. Pain and perceived tension were scored on a visual analog scale, and fatigue on a Borg scale. Pain development was most pronounced in the shoulder and neck region. There was a weak tendency of those reporting pain in the shoulder region to generate higher EMG activity in the trapezius relative to those with no shoulder pain at the end of the test. No such relationship was observed for the other muscles. Perceived tension during the test was weakly related to pain and strongly related to fatigue at the end of the test, but not to EMG level. It is concluded that the mean level of the EMG response is of little consequence for pain development during stressful conditions. It is argued that other physiological responses such as prolonged activity in low-threshold motor units, whereby the surface EMG response can serve as a marker, can be important for shoulder pain originating in the trapezius muscle.     

Psychophysiological reactivity to mental arithmetic stress in Black and White normotensive men.

34 Black and 42 White male normotensives 34–55 yrs old performed a mental arithmetic task while blood pressure, heart rate, and skin conductance were recorded. Compared with Whites, Blacks had significantly higher baseline diastolic blood pressure and lower skin conductance levels. These effects persisted during performance of the mental arithmetic task. When baseline differences were covaried, there were no significant physiological effects associated with the task. There were no significant race or family history effects, and task performance did not influence the outcome. Failure to demonstrate greater cardiovascular reactivity in Blacks and all men with a positive family history of hypertension is discussed with regard to possible survivor effects and methodologic limitations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alteration by phosphatidyl serine of tension responses and 45Ca distribution in aortic smooth muscle

The effects of phosphatidyl serine (PS) on 45Ca distribution, 45Ca movements and contractions were examined in rabbit aortic smooth muscle. Contractile responses to submaximal concentrations of norepinephrine and histamine were potentiated by prior exposure to PS, but equivalent responses to potassium were unaffected. Addition of PS to the incubation solution decreased 45Ca uptake; exposure of aortic strips to PS during washout of either 45Ca or promethium (147Pm) resulted in maintained increases in efflux. These PS-induced alterations in net loss of 45Ca or 147Pm can be attributed to a decreased membrane reuptake and/or rebinding. However, the presence of PS during the washout significantly reduced the increases in 45Ca efflux rate elicited with either 0.05 mM concentrations of Ca++ or ethylenediamine tetraacetic acid. Thus, in rabbit aortic smooth muscle, exogenous PS can alter the availability and/or exchangeability of a membrane-bound Ca++ fraction. By specifically increasing the affinity for Ca++ at relevant membrane sites or stores. PS may enhance the ability of vascular smooth muscle to respond to stimulatory agents that mobilize Ca++ from these sites and, in this manner, potentiate contractile responses.     

Left ventricular, peripheral vascular, and neurohumoral responses to mental stress in normal middle-aged men and women. Reference Group for the Psychophysiological Investigations of Myocardial Ischemia (PIMI) Study

BACKGROUND: The normal cardiovascular response to mental stress in middle-aged and older people has not been well characterized. METHODS AND RESULTS: We studied 29 individuals 45 to 73 years old (15 women, 14 men) who had no coronary risk factors, no history of coronary artery disease, and a negative exercise test. Left ventricular (LV) volumes and global and regional function were assessed by radionuclide ventriculography at rest and during two 5-minute standardized mental stress tasks (simulated public speaking and the Stroop Color-Word Test), administered in random order. A substantial sympathetic response occurred with both mental stress tests, characterized by increases in blood pressure, heart rate, rate-pressure product, cardiac index, and stroke work index and rises in plasma levels of epinephrine and norepinephrine but not beta-endorphin or cortisol. Despite this sympathetic response, LV volume increased and ejection fraction (EF) decreased secondary to an increase in afterload. The change in EF during mental stress-varied among individuals but was associated positively with changes in LV contractility and negatively with baseline EF and changes in afterload. EF decreased > 5% during mental stress in 12 individuals and > 8% in 5; 3 developed regional wall motion abnormalities. CONCLUSIONS: Mental stress in the laboratory results in a substantial sympathetic response in normal middle-aged and older men and women, but EF commonly falls because of a concomitant rise in afterload. These results provide essential age- and sex-matched reference data for studies of mental stress-induced ischemia in patients with coronary artery disease.     

Interpersonal stress and pain behaviors in patients with chronic pain.

Evaluated the role of interpersonal stress in eliciting pain behavior. 34 male patients with chronic back pain and their wives participated in a randomized between-groups study examining the effects of 2 interactional conditions (i.e., maritally focused stress interview and neutral talking control task) on subsequent persistence in a physically demanding task and with self-reports of pain. Results show that a greater proportion of patients in the stress interview group terminated the physical activity task prematurely, compared with controls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Type A behavior, personality hardiness, and cardiovascular responses to stress.

Type A behavior and hardiness were examined as predictors of cardiovascular responses to stress in 68 male undergraduates. Systolic and diastolic blood pressure (SBP and DBP) and heart rate were monitored while subjects performed a difficult mirror-tracing task. Type A assessments based on the Structured Interview, but not those based on the Jenkins Activity Survey, were associated with significantly enhanced SBP and DBP elevations. Hardiness was associated with significantly reduced DBP responsiveness. In addition, a significant interaction indicated that the Type B-high hardiness group showed the least DBP reactivity. A near-significant interaction (p?=?.06) suggested that Type B-high hardiness subjects also reported the least anger. Further exploration of the data indicated that the challenge component of hardiness accounted for its relationship to DBP reactivity. These results have implications both for the psychophysiologic study of Type A behavior and for understanding the health-promoting effects of hardiness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thinking about a close relationship differentially impacts cardiovascular stress responses among depressed and nondepressed women.

Objective: Individuals with depression and low social support are at elevated risk for developing cardiovascular disease—presumptively through mechanisms involving dysregulated stress physiology. While depressed individuals often report diminished social support and elevated levels of social distress, few studies have examined how social factors impact stress-related cardiovascular activity in depressed samples. Accordingly, we evaluated the social modulation of stress-related cardiovascular activity in a sample of 38 medically healthy, unmedicated depressed and nondepressed individuals. Methods: Cardiovascular and psychological measures were obtained before and after depressed and nondepressed women engaged in a speech stress task. To evaluate the impact of social factors on stress responses, half of the women completed the speech stress task first, while the other half completed the speech stress after engaging in a relationship-focused imagery task. Results: Nondepressed women who first thought about a close relationship displayed global attenuations in blood pressure throughout the subsequent stress task, consistent with a stress-buffering effect of perceived social support. Conversely, depressed women who first thought about a close relationship displayed global elevations in blood pressure throughout the subsequent stress task, consistent with a stress-enhancing effect of perceived social distress in depressed women. Conclusion: Thinking about a close relationship differentially impacted subsequent cardiovascular activity during an evocative stressor in depressed and nondepressed women. Understanding the social context in which stress is experienced may aid in identifying, and ultimately attenuating, cardiovascular risks observed among patients with major depressive disorder. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Masseter muscle hyperactivity and myofascial pain dysfunction syndrome: a relationship under stress

Myofascial pain dysfunction syndrome (MPD) of the temporomandibular joint (TMJ) is a psychophysiological disorder that develops because of hyperactive muscles of mastication. Ten women meeting criteria for MPD and 12 symptom-free women participated in the study. The rationale for this study was to observe cardiovascular and masseter muscle changes during four contiguous experimental periods: baseline/adaptation, reaction time, recovery, and relaxation. MPD patients showed less masseter muscle activity and higher heart rates at baseline than controls. Controls had significantly higher masseter EMG activity during reaction time. Both groups showed significant elevation in masseter muscle activity and heart rate over the 14-min reaction period. MPD patients' recovery from stress was equivalent to controls' for both heart rate and masseter muscle activity. MPD patients exhibited significantly slower reaction times than controls. The results suggest that masseter muscle hyperactivity may not account for the development and maintenance of MPD.     

Effects of stress inoculation training on anxiety, stress, and academic performance among adolescents.

The effectiveness of a preventive stress inoculation program for adolescents that consists of a blend of progressive muscle relaxation, cognitive restructuring, and assertiveness training was examined. Trainees were compared with an empirically derived control group on measures of anxiety, stress, and academic performance. Compared with controls, the training program participants showed significantly greater improvements on self-report measures of trait anxiety and stress-related symptoms at posttest. These improvements were maintained at a 4-wk follow-up assessment. There were no significant differences between the 2 groups in academic achievement at either posttest or follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions among operator variables, system dynamics, and task-induced stress.

The relative efficiency of several machines is studied under conditions of operator stress. "Forty-eight naval enlisted men served as Ss in the three experiments—16 Ss per experiment." In each of the 3 experiments, the Ss were divided into 2 groups of 8: an experimental and a control group. 3 systems were employed: acceleration control, acceleration aided control, and position control. In Experiment I, one group used the acceleration; the other used the acceleration aided. In Experiment II, one group used the acceleration and the other the acceleration aided. In Experiment III, one group used position control and the other the acceleration. Stress was introduced in all cases as the trials progressed. "The better systems retained their advantage under stress… . Thus, within the confines of the present studies the "engineering" variable of system dynamics proved to be ascendent over the "psychological" variables of selection and training in determining relative performance under stress." (PsycINFO Database Record (c) 2010 APA, all rights reserved)