Muscle Learning Therapy—Efficacy of a Biofeedback Based Protocol in Treating Work-Related Upper Extremity Disorders

Work-related upper extremity disorders (WRUEDs) continue to present significant treatment and financial challenges to providers, employers, and insurers. This retrospective study reviews outcomes for 309 subjects who, between 1995 and 1999, were referred through the workers' compensation system for treatment of computer keyboard- and mouse-related WRUED injuries. The mean length of time from the recorded date of injury to the date of intake was 12.9 months. Subjects were offered a 12-visit course in muscle learning therapy (MLT). MLT is an operant conditioning program which uses surface electromyography (sEMG) to train injured workers to control their muscles during work activities. Patient response to therapy was obtained by a therapist-administered questionnaire during Visit 8 of 12. A group of 309 subjects, who had failed to respond to a previous course of therapy (typically physical therapy), reported significant improvements of pain in the neck, thorax, and upper extremities. Ninety six percent reported that they felt more in control, 86% reported feeling better overall, and 81% reported either working the same and feeling better or working and accomplishing more. This study provides preliminary support for this approach and provides justification for controlled clinical trials in the future.     

A study of neurophysiological measurements and various function tests on workers occupationally exposed to vibration

Summary Seventy male air grinder operators and 72 age-matched control workers were examined. Both groups of workers worked in the warm climate (20°–33°C) of southern Taiwan. None of the workers had symptoms of white fingers. The investigation program comprised: (1) case history, (2) physical examination, (3) determination of maximal motor conduction velocity, proximal and distal sensory conduction velocity (NCV) of the median and ulnar nerves of the right upper extremity, (4) measurement of skin temperature, nail press test, pain threshold and vibratory sense threshold of the upper extremities, and (5) testing of the motor function. The dose-effect correlation between the NCV, various function tests and total operating time (TOT) was performed by multiple stepwise regression analyses. The regression analyses revealed a statistically significant correlation (dose/effect) between the six NCV, vibratory sense threshold, pain threshold and age, as well as TOT.     

Accumulation of Selenium and Lack of Severe Effects on Productivity of American Dippers (Cinclus mexicanus) and Spotted Sandpipers (Actitis macularia)

Selenium has been found at elevated concentrations in water, sediments, and aquatic biota in the Elk River (British Columbia, Canada) and some of its tributaries downstream of several coal mines. Selenium water concentrations in those areas exceed Canadian and British Columbia guidelines and are above levels at which adverse effects to fish and waterfowl could occur. We compared selenium concentrations in the eggs of two riverine waterbirds, American dippers and spotted sandpipers, with measures of productivity: the number of eggs laid, egg hatchability, and nestling survival. In American dippers, the mean egg selenium concentration from the exposed areas, 1.10±SE 0.059 g/g wet weight, was indistinguishable from the reference areas, 0.96±SE 0.059 g/g wet weight. For spotted sandpipers, the mean egg selenium concentration in the exposed areas, 2.2±0.5 g/g wet weight, was significantly higher than in the reference areas, 1.2±0.14 g/g wet weight, but less than reported thresholds for waterfowl and other shorebirds. There were no significant differences in egg hatchability between dippers in reference and exposed areas, but reduced hatchability was apparent for sandpipers in exposed locations. Despite the slightly reduced hatchability in sandpipers, overall productivity was higher than regional norms for both species; thus, selenium did not affect the number of young recruited to local populations. We did not observe teratogenic effects in either species, although none was expected at these concentrations. Despite moderately high selenium concentrations in the water, mean egg selenium concentrations were less than predicted from uptake models. We hypothesise that the relatively low uptake of selenium into the eggs of the two waterbirds in this study is likely due to their lotic environments low biological transformation and uptake rates.     

Polychlorobiphenyls, ΣDDT,and hexachlorocyclohexane isomers in the western North Pacific ecosystem

Polychlorobiphenyls (PCBs), DDT (p,p-DDT,p,p-DDD, andp,p-DDE and HCH isomers (hexachlorocyclohexanes including , , and isomers) were determined in a marine food chain, including seawater, zooplankton, myctophid, squid and striped dolphin collected from the western North Pacific waters. The concentrations of these pollutants increased in higher trophic levels, where the highest bioconcentration factors (concentration ratio in organisms to water), as much as 10⁷, were obtained from both PCBs and DDT in striped dolphin. The proportions of highly chlorinated biphenyls,p,p-DDE and -HCH increased in higher-ranking predators. These observations suggest that the bioaccumulation mechanisms in lower trophic levels depend primarily on the physicochemical properties of pollutants, whereas those in higher trophic levels are affected by the biodegradability of the pollutants and the metabolic capacity and life-span of the organisms.     

Comprehensive pediatric primary care vs traditional care in an israeli population: Their influence on pediatric emergency room use and hospitalization

Emergency room (ER) utilization and hospitalization were studied as indicators of the impact of improvements in pediatric primary care services in an Israeli development town, Ofakim, population 12,000. One of the two pediatric services was upgraded in 1976 through the introduction of pediatric faculty, integration of preventive and curative services and conversion of the medical records to a problem-oriented format ( experimental clinic B ). The primary care system remained unchanged in the second clinic ( traditional clinic A ). During 1980, ER utilization by the B clinic population was 9.3/100 compared with 17.6/100 for the A clinic population. Fifty two percent of the B clinic population patients reaching the ER were hospitalized compared with 25% of A clinic patients.The lower ER utilization rate represents a significant saving for the health services, and educational interventions are suggested from the study. Analysis of ER utilization data seems to offer useful information for overall planning and monitoring of ambulatory services for a community.Corresponding author.     

Psychosocial stressors associated with Mexican migrant farmworkers in the midwest United States

Although estimates suggest that there are upwards of 5 million migrant farmworkers in the United States, scant research has explored the stressors associated with their lifestyle. Contrary to previous work, the present study directly explored migrant farmworkers' own perceptions of what is difficult in their lives. The purposes of the present study were to qualitatively explore, from a phenomenological standpoint, the stressors associated with living as a migrant farmworker in the Midwest United States; and to determine the stressors that were most strongly related to symptoms of anxiety and depression. The findings indicated that 18 stressors were commonly experienced by the migrant farmworkers and that the farmworkers experienced overall elevated levels of anxiety and depression. A number of stressors that were not previously reported in the literature were identified. The stressors of rigid work demands and poor housing conditions were significantly associated with higher levels of anxiety and low family income/living in poverty and rigid work demands were significantly associated with depression. Implications of findings and prevention strategies are discussed.     

Blood styrene concentrations in a “normal” population and in exposed workers 16 hours after the end of the workshift

Summary Blood styrene was measured by a gas chromatography-mass spectrometry method in 81 normal people and in 76 workers exposed to styrene. In the normal subjects, styrene was also tested in alveolar and environmental air. Styrene was found in nearly all (95%) blood samples. Average styrene levels in the normal subjects were 221 ng/1 in blood (Cb), 3 ng/1 in alveolar air (Ca) and 6 ng/1 in environmental air (Ci). Styrene levels did not differ significantly between smokers and non-smokers, 95% of values being below 512 ng/1 in Cb, 7 ng/1 in Ca and 15 ng/l in Ci. In workers with an average exposure to styrene of 204 g/l, at the end of the workshift, mean blood styrene concentration was 1211 g/l. In blood samples collected at the end of the Thursday shift, styrene levels were significantly higher (1590 g/1) than those found at the end of the Monday shift (1068 g/l. A similar difference was found in samples taken the morning after exposure (60 and 119 g/l, respectively). Significant correlations between blood and environmental styrene were found both at the end of the shift and the morning after exposure (r=0.61 and 0.41, respectively). In workers occupationally exposed to styrene, 16 h after the end of the workshift, blood styrene (94 g/l) was significantly higher than that found in the normal subjects (0.22 g/l). The half-life of blood styrene was 3.9 h.     

Biochemical and physiological aspects of 2,5-hexanedione: endogenous or exogenous product?

Summary This article reports results regarding two different physiological aspects of 2,5-hexanedione (2,5-HD). The first is the relationship between free 2,5-HD (the fraction of real 2,5-HD) and total 2,5-HD (2,5-HD obtained from acid hydrolysis) in urine and blood of workers exposed ton-hexane. The second part of the study is an attempt to clarify physiological excretion of 2,5-HD in subjects not occupationally exposed ton-hexane. The concentration of free 2,5-HD in urine of workers exposed ton-hexane is about 8% of total urinary 2,5-HD. In blood, free 2,5-HD is about 50% of the total. The serum concentration range of total and free 2,5-HD in workers from whom blood was taken was 33–418 g/l and 14–283 g/l respectively. In subjects not exposed ton-hexane, urinary concentration of 2,5-HD ranged between 0.17 and 0.98 mg/1, the urinary excretion rate between 0.23 and 0.57g/min, and renal clearance between 14 and 66 ml/min. The blood concentration of 2,5-HD in nonexposed subjects was 6–30g/1. Fluctuations typical of a circadian rhythm were not observed for 2,5-HD in blood or urine. We think that 2,5-HD is mainly a product of intermediate metabolism in the human body. Only a minimal part could derive fromn-hexane as a ubiquitous micropollutant.     

Correlation between vibration-induced white finger and symptoms of upper and lower extremities in vibration syndrome

Summary The correlation was investigated between the frequency of attacks of vibration-induced white finger (VWF) and numbness or coldness of the fingers and legs in patients with vibration syndrome. Some 1687 patients with vibration syndrome were examined and of these 342 chain-saw operators and 277 rock-drill operators had no disease other than vibration snydrome. Then subjects were matched by age and period of treatment within three years. In the last analysis, 20 in the VWF almost everyday group or in the never group, and 40 in the occasionally group were selected from the chain-saw operators, and from the rock-drill operators 32 in the VWF everyday or the never group and 64 in the occasionally group. The present study showed that, with the frequency of VWF attacks, patients had a higher prevalence of coldness not only in the fingers but also in the legs. These findings suggest a correlation between the severity of circulatory disturbances of the upper extremities and that of the lower ones in patients with vibration syndrome. Further studies on circulatory disturbances in the leg are required.     

The organic solvent syndrome

Summary A study was conducted to investigate the existence of a specific neurotoxic effect due to long-term exposure to organic solvents. A comparison was made regarding diagnoses, symptoms and other relevant medical data between persons receiving a disability pension on the basis of a neuropsychiatric disorder selected from an exposed (painters) and non-exposed (construction workers) trade organization. Information was collected from their medical files at the occupational health department. Concerning diagnoses and symptoms, no significant differences were found between exposed and non-exposed patients. No indications were found for the existence of a typical complex of symptoms associated with exposure to organic solvents among painters in The Netherlands. The number of reported symptoms was not related to the duration of exposure, thus lending no support for a dose-effect relationship. If a neurotoxic effect does exist among Dutch painters, it is of a non-specific type and not clearly distinguishable from other mental disorders.     

Forestry workers involved in aerial application of 2,4-dichlorophenoxyacetic acid (2,4-D): Exposure and urinary excretion

Urinalysis was conducted on six volunteer workers involved in mixing and loading 2,4-D ester solutions into aircraft and in guiding the spray aircraft in two conifer release programs during 1981 and 1982. Exposures were reduced by wearing a full line of protective clothing. Two females and one male were involved in mixing the spray for 109 aircraft loads over an 11-day period in 1981. During the 1981 operation, the highest daily excretion of 2,4-D in the urine was 0.30, 0.94 and 9.59 g/kg body weight for the three workers. In 1982, three male workers were involved, one diluting the concentrated solution and loading the aircraft, and two marking the swaths for aerial application over an 18 day period. The highest daily excretion of 2,4-D in the urine was 7.73, 8.37, 22.2 g/kg body weight for the three workers. One of the authors, acting as a bystander, was directly sprayed in the 1982 season and 0.44% was absorbed based on urine analysis. The highest daily excretion of 2,4-D in his urine was 4.75 g/kg body weight. For all seven people, the calculated exposure was less than the no-effect level of 10 mg/kg of body weight/day by a large margin of safety. The presence of 2,4-D in urine samples in the pre-spray period and its slow disappearance during the post spray period prompted further investigation. Swabs of internal surfaces of living quarters revealed deposits of 2,4-D from 0.7 to 288 g/0.1m² and on spray equipment from 0.7 to 184 g/0.1m².     

Study of endemic scrapie in a flock of ≪ ile de France≫ sheep

An Ile de France flock was studied over a period of 5 years. The authors found similar results concerning incidence and age of onset of scrapie to those found in the English literature. A close relationship was established between the age of the dam at parturition and the age of the progeny at onset of scrapie. In the later years of our study, scrapie was detected in younger animals than in the earlier years, suggesting a phenomenon of genetic anticipation . Increased fecundity in this endemically affected flock might represent a form of selection which favorises the occurrence and maintenance of the disease within the flock.Corresponding author.     

Media reviews

Of the three films reviewed in this issue, only the first, All Women Have Periods, deals with both areas of sexuality and disability. The second film, A Masturbatory Story, deals with sexuality but not disability. The third film, A Different Approach, deals with disability but not sexuality. The reason I have included the last two films are that A Masturbatory Story is one of the best, most permission giving films I have seen on the subject of masturbation and A Different Approach while focusing on employment of the disabled, is one of the most entertaining and effective films I have seen dealing with attitudes.     

Internal exposure to organic substances in a municipal waste incinerator

Summary Fifty-three persons occupied in a municipal waste incinerator were examined with respect to their internal exposure to organic substances which may be produced during pyrolysis of organic matter. For this purpose the levels of benzene in blood, polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB) in plasma, and mono- (MCPs), di- (DCPs), tri- (TCPs), tetra-(TECPs) and pentachlorophenol (PCP) and hydroxypyrene in urine were determined. For control purposes, 431 men and women were examined. Significantly higher values for the workers were found for the excretion of hydroxypyrene [median (m): 0.24vs 0.11 g/l; non-smokers], 2,4/2,5-DCP (m: 10.5 vs 3.9 g/l) and 2,4,5-TCP (m: 1.2 vs 0.8 g/l) and for the HCB level in plasma (m: 4.4 vs 2.8 g/l). For the concentrations of 4-MCP and 2,3,4,6/2,3,5,6-TECP, the controls had significantly higher concentrations in urine than did the workers in the incineration plant (m: 4-MCP 1.7 vs 1.2; 2,3,4,6/2,3,5,6-TECP: 1.2 vs 0.3 g/l). No significant differences between workers and controls were detected with respect to benzene in blood (m: 0.20 vs 0.28 g/l; non-smokers), 2,4,6-TCP and PCPs in urine (m: 0.85 vs 0.60 and 2.2 vs 2.2 g/l) or the levels of PCB congeners in plasma (m: 138, 153, 180: 5.6 vs 4.1 g/l). The elevated levels of hydroxypyrene, 2,4/2,5-DCP, 2,4,5-TCP and HCB in biological material may be related to the incineration of the waste. These elevations, however, are very small and are of interest more from the environmental than from the occupational point of view.     

Making sense of illness: late-in-life migration as point of departure for elderly Iranian immigrants' explanatory models of illness

This article is based on data gathered through 60 qualitative interviews conducted within the realm of three research projects that have used culture-appropriate lenses to study the postmigration situation of late-in-life Iranian immigrants to Sweden. The findings gathered through these studies were interpreted against the backdrop that culturally appropriate nursing theories provide. This meant that it was, at times, these elders backgrounds as cultural others that were implicitly used to make sense of the various issues that were brought to the fore by these studies. The particular issue with which this article is concerned is the unusualness of these elders explanatory models of illness. Inspired by the concept definition of situation in the symbolic interactionist perspective and by the feeling that this perspective might bring about a different interpretation of the original findings regarding their understandings of illness and disease, we set out to conduct a secondary analysis of these elders explanatory models of illness. The findings presented in this article will show how the elderly Iranian immigrants interviewed in these three studies utilize the process of late in life migration as a point of reference for their understandings of what has caused the illnesses from which they suffered. Hereby we will suggest that the unusualness of their explanatory models of illness might be best understood if we focus on what they shared as immigrants (i.e., the fact that the process of late-in-life migration has made their culture obsolete) as opposed to what they shared as Iranians (i.e., their culture of origin).     

Visual disturbances after industrial triethylamine exposure

Summary Among 19 workers in a polyurethane foam production plant, visual disturbances (foggy vision, blue haze, and sometimes halo phenomena) were reported on a total of 47 occasions by five workers over 11 weeks. The symptoms were associated with triethylamine exposure. Time-weighted average levels of 12 to 13 mg/m³ were recorded at work operations associated with symptoms, and 4 to 5 mg/m³ at other tasks. Twice as high peak levels were recorded. A detailed medical examination of the five affected workers in a free interval did not reveal any signs of permanent eye disease.     

Monitoring of Antifouling Booster Biocides in Water and Sedimentfrom the Port of Osaka, Japan

Concentrations of booster antifouling compounds in the port of Osaka, Japan were assessed. Concentrations of Sea-Nine 211 (4,5-dichloro-2-n-octyl-3-isothiazolone), thiabendazole (2-(4-thiazolyl)-benzimidazole), IPBC (3-iodo-2-propynyl butylcarbamate), Diuron (3,4-dichlorophenyl-N, N-dimethylurea), Irgarol 1051 (2-methylthio-4-t-butylamino-6-cyclopropylamino-s-triazine), and M1 (2-methylthio-4-t-butylamino-6-amino-s-triazine) in port water samples were in the range of <0.003–0.004 g L^–1, <0.0008–0.020 g L^–1, <0.0007–1.54 g L^–1, <0.0008–0.267 g L^–1, and <0.0019–0.167 g L^–1, respectively. IPBC was not detected in the water samples, but the concentration of Diuron was higher than any previously reported. The concentrations of Sea-Nine 211, thiabendazole, Diuron, Irgarol 1051, and M1 in sediment samples were in the range of <0.04–2.4 g kg^–1 dry, <0.08–1.2 g kg^–1 dry, <0.64–1350 g kg^–1 dry, <0.08–8.2 g kg^–1 dry, and <0.18–2.9 g kg^–1 dry, respectively. IPBC was again not detected. The levels of Sea-Nine 211, Diuron, and Irgarol 1051 in water and sediment samples were high in a poorly flushed mooring area for small and medium-hull vessels. Levels of Diuron and Irgarol 1051 were highest in summer. The concentration of Sea-Nine 211 in water increased between August and October 2002. Except for M1, increases in the levels of booster biocides in sediment were observed during the study period. The sediment–water partition (Kd) was calculated by dividing the concentrations in sediment by the concentrations in water. The Kd values for Sea-Nine 211, thiabendazole, Diuron, Irgarol 1051, and M1 were 690, 180, 2700, 300, and 870. The Kd value for these alternative compounds was lower than for TBT.     

Levels of β-HCH,HCB, p,p′-DDE,p,p′-DDT and PCBs in human milk from a continental town in Croatia,Yugoslavia

Summary Concentrations of -HCH, HCB, p,p-DDE, p,p-DDT and PCBs were determined by gas chromatography in 50 human milk samples collected from the general population during 1981/1982 in a continental town in Croatia (Yugoslavia). The samples were collected between one and 22 weeks after delivery from mothers breast-feeding one child only. The mothers' age was 18 to 31 years, and they were nursing their first or second child. All 50 samples contained -HCH, HCB, p,p-DDE and PCBs, whereas p,p-DDT was present in 37 samples. The concentrations of -HCH, HCB, p,p-DDE, p,p-DDT and PCBs expressed on a whole milk basis were (median in g/kg): 11, 7.1, 67, 7.3 and 22 respectively, and expressed on a fat basis (median in mg/kg): 0.28, 0.21, 1.9, 0.18 and 0.62 respectively. The fat content was 3.7% (median). PCBs were present in a mixture containing penta-, hexa- and heptachlorobiphenyls.     

A Cross-Sectional Assessment of the ACGIH TLV for Hand Activity Level

The ACGIH Worldwide Threshold Limit Value (TLV) for hand activity considers average hand activity level or HAL and peak hand force. We report cross-sectional data that assess the validity of the TLV with respect to symptoms and selected upper extremity musculoskeletal disorders among workers. The prevalence of symptoms and specific disorders were examined among 908 workers from 7 different job sites in relation to the TLV. Worker exposures were categorized as above the TLV, above the TLV Action Limit but below the TLV, or below the TLV Action Limit. Symptoms in the distal upper extremities did not vary by TLV category. Tendonitis in the wrist/hands/fingers did not vary by TLV category, but elbow/forearm tendonitis was significantly associated with TLV category. All measures of carpal tunnel syndrome were associated with TLV category. In all instances, prevalence of symptoms and specific disorders were substantial in jobs that were below the TLV action limit, suggesting that even at acceptable levels of hand activity, many workers will still experience symptoms and/or upper extremity musculoskeletal disorders, which may be important in the rehabilitation and return to work of injured workers. Future analyses need to examine the incidence of symptoms and upper extremity musculoskeletal disorders prospectively among workers in relation to the TLV for hand activity.     

Assessment of thyroid,testes, kidney and autonomic nervous system function in lead-exposed workers

Summary The objective of the study was to assess whether moderate occupational exposure to lead may be associated with early changes in potential target organs (thyroid, testes, kidney, autonomic nervous system). Workers exposed to lead in a lead acid battery factory (n = 98; mean blood lead 51 g/dl, range 40–75 g/dl) and 85 control workers were examined. None of the indicators of kidney function (in urine: retinol-binding protein, ₂-microglobulin, albumin,N-acetyl--d-glucosaminidase; in serum: creatinine, ₂-microglobulin), endocrine function (follicle-stimulating hormone, luteinizing hormone, thyroid-stimulating hormone, thyroxine, triiodothyronine) and autonomic nervous system (R-R interval variations on the electrocardiogram) were correlated with lead exposure (blood lead or duration of exposure) or showed significantly different mean values between the exposed group and controls. These results and an assessment of the published data suggest that compliance with the Directive of the Council of the European Communities on lead exposure (health surveillance in workers whose lead in blood exceeds 40 g/dl and removal from exposure when blood lead exceeds 70–80 g/dl) would prevent the occurrence of significant biological changes in the majority of lead-exposed workers.