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Biomedical subjects

B Silverstein

Publications and source records attributed to B Silverstein.

At least 19 recordsLinked to original sources
PubMed2006

Quantifying repetitive hand activity for epidemiological research on musculoskeletal disorders--part I: individual exposure assessment.

An exposure measurement approach is described for quantifying repetitive hand activity of individual workers in a prospective epidemiological study on work-related upper extremity musculoskeletal disorders. A total of 733 subjects were involved in this study at the baseline. Hand activities were quantified by force and repetition. Force levels were measured by workers' self-reports, ergonomists' estimates based on observation and measurements with instrumentation. Repetition levels were measured by detailed time-motion analyses using two repetitive hand activity definitions and ergonomists' estimates using scales for the American Conference of Governmental Industrial Hygienists hand activity level and the Strain Index. Results showed that the present exposure assessment approach seems to be able to quantify force level and repetitiveness of hand activities. Repetitive hand activity is quantified differently depending on whether forceful hand exertion or repetitive muscle activity is used as the definition. These hand activity definitions may quantify different physical exposure phenomena. Individual exposure assessment is important in epidemiological research of musculoskeletal disorders as there are interactions between the individual subjects and the measured parameters. These interactions may vary between exposure parameters.

Adolescent↗
PubMed2006

Quantifying repetitive hand activity for epidemiological research on musculoskeletal disorders--part II: comparison of different methods of measuring force level and repetitiveness.

This paper focuses on comparisons between the different methods of assessing repetitive hand activities. Various methods were used to measure hand force and repetitiveness of hand activities on 733 subjects in the study described by Bao et al. (2006). Two definitions of repetitiveness were used in analysis of detailed time studies of repetitive hand activities and four parameters of the American Conference of Governmental Industrial Hygienists (ACGIH) hand activity level (HAL) and the Strain Index methods were estimated by ergonomists and used to quantify repetitiveness. Hand forces were measured or estimated using three different methods: 1) measured with a force gauge or mimicked on a force gauge (force matching); 2) estimated by ergonomists using rating scales; 3) self-reports by subjects. The jobs were also evaluated using the ACGIH HAL and Strain Index methods when different repetitiveness quantification methods were used. Results showed that different definitions of repetitive exertion might lead to measuring different physical exposure phenomena and produce very different results. There were poor correlations between the measures of repetitiveness estimated by the different methods. Correlations between force quantifications using different methods were also poor. This suggests that parameters measured by different methods might not be interchangeable. Both the ACGIH HAL and Strain Index methods identified more 'hazardous' jobs when repetitiveness was estimated by ergonomists than when it was calculated by detailed time studies of forceful hand exertions. The Strain Index method identified more 'hazardous' jobs than the ACGIH HAL method. Overall, the between-methods agreements were found to be moderate to substantial.

Adolescent↗
PubMed2005

Self-reported musculoskeletal symptoms and observed risk factors in bareroot tree nurseries.

A cross-sectional study of jobs at four bareroot reforestation tree nurseries in Washington and Oregon investigated the prevalence of musculoskeletal symptoms and potential work-related musculoskeletal disorders (WMSDs), and analyzed their association with physical and psychosocial risk factors of the jobs. Questionnaires were used to assess symptoms and psychosocial factors. Direct observational work sampling was utilized to estimate physical risk factors. The response rate for the questionnaires was 41% (203 subjects), of which 72% reported recurring symptoms in the past year. The most common body region was the wrist/hand (42%). Pain was the most commonly reported symptom. Forty-one percent of the subjects had at least one potential WMSD, the hand region having the greatest number of cases (n = 51). The average age of those with and without potential WMSDs did not significantly differ; however, tenure at the nursery (p < 0.03) did. Being female (OR = 7.37; 95% CI = 2.75, 19.7,) high job satisfaction (OR = 0.32; 95% CI = 0.15, 0.72), and having a second job (OR = 3.76; 95% CI = 1.12, 12.57) were significantly associated with potential WMSDs. No significant difference in WMSD prevalence was found between the field and packing shed areas of the nurseries (p = 0.88). Pinch gripping was observed 24% of the time in the shed and 8% of the time in the field. Torso flexion was observed more often in the field than the shed (38% vs. 18% of the time). This study found that both physical and psychosocial factors associated with WMSDs are present in bareroot trees nurseries.

Adult↗
PubMed2001

Comparison of self-report, video observation and direct measurement methods for upper extremity musculoskeletal disorder physical risk factors.

The prevention of work-related musculoskeletal disorders has become a national priority in many countries. Increasingly, attempts are made to quantify those exposures that increase risk in order to set exposure limit values. This study used commonly employed field measurement methods and tools in order to perform an inter-method comparison between three primary methods of risk factor exposure assessment: self-report questionnaires, observational video analysis and direct measurement. Extreme posture duration, repetition, hand force (estimated from electromyography) and movement velocity were assessed for 18 subjects while performing each of three jobs processing tree seedlings. Results indicated that self-reports were the least precise assessment method, which consistently overestimated exposures for each of the measured risk factors. However, adjustment of the reports as psychophysical scales may increase agreement on a group level. Wrist flexion/extension duration and repetition were best measured by electrogoniometer. Electrogoniometric measures of wrist deviation duration and frequency were less precise than video analysis. Forearm rotation duration and repetition, grip force and velocity appeared to be best quantified by direct measurement as measured by electrogoniometer and electromyography (EMG) (as root-mean-square amplitude). The results highlight the fact that it is as important to consider and report estimated measurement error in order to reduce potential exposure misclassification in epidemiologic studies.

Arm↗
PubMed1999

Reproducibility of a self-report questionnaire for upper extremity musculoskeletal disorder risk factors.

A self-report questionnaire was developed to evaluate the potential for assessment of possible risk factors for musculoskeletal disorders. Visual-analog and categorical scales were designed to represent responses relating to primary work as well as a second job and hobbies or non-work activities. 71 tree nursery workers completed the scales twice in consecutive weeks. Agreement between means of the two questionnaire administrations was 0.80 or higher for all scales. Intraclass correlation coefficients ranged between 0.59 and 0.69 for the primary job hand/wrist responses and between 0.49 and 0.82 for non-work/hobby neck and upper arm scales. These results show potential for future application of similar scales in industry or temporary and seasonal work to evaluate exposure to upper extremity risk factors.

Adult↗
PubMed1999

Gender difference in the prevalence of clinical depression: the role played by depression associated with somatic symptoms.

OBJECTIVE: This study tested the hypothesis that female subjects may exhibit a higher prevalence than male subjects of depression associated with somatic symptoms but not a higher prevalence of depression not associated with these other symptoms. METHOD: The author reanalyzed research interview data on major depression from the National Comorbidity Survey, dividing respondents into those who met overall criteria for major depression and exhibited fatigue and appetite and sleep disturbance ("somatic depression") and those who met overall criteria but did not exhibit these somatic criteria ("pure depression"). RESULTS: Female subjects exhibited a higher prevalence than male subjects of somatic depression but not a higher prevalence of pure depression. Somatic depression was associated with a high prevalence of anxiety disorder and, among female subjects, with body aches and onset of depression during early adolescence. CONCLUSIONS: The gender difference in depression may result from a difference in a specific subtype of anxious somatic depression.

Adolescent↗
PubMed1999

Role of physical load factors in carpal tunnel syndrome.

Epidemiologic and experimental studies were reviewed to assess the role of postural factors, high handgrip and pinch forces, repetitive hand and wrist movements, external pressure, and vibration in the occurrence of carpal tunnel syndrome (CTS). Forceful repetitive work, vibration, and extreme wrist postures have been associated with CTS in several epidemiologic studies. Experimental studies have shown that certain forearm, wrist, and finger postures, even moderate hand loads and external pressure on the palm, can increase carpal tunnel pressure (CTP) at least temporarily to levels at which nerve viability is threatened. It is concluded that while more research is needed, there is sufficient information to suggest that reducing the duration, frequency or intensity of exposure to forceful repetitive work, extreme wrist postures and vibration is likely to result in a reduction of the incidence or severity of CTS in working populations.

Animals↗
PubMed1998

An ergonomic characterization of work in concrete form construction.

Concrete formwork construction was identified as the area of greatest ergonomic risk in unionized carpentry by both managers and unionized carpenters. Ergonomic risks were identified and characterized using (a) 1220 randomized work samples from videotape, (b) 82 worker discomfort surveys, (c) on-site observation, and (d) labor-management focus group discussions. Results showed that carpenters spent over 40% of the day in a forward torso flexion posture and over one-third of the day working at or below knee level. Hammering was the single most frequently performed activity at approximately 17% of the day. The body location with the highest reported prevalence of symptomatic disorders was the lower back at 48% followed by the forearms/wrist at 37%. It was concluded that carpenters are exposed to significant hazards in formwork construction, and that opportunities exist for the implementation of ergonomic interventions.

Adult↗
PubMed1998

Claims incidence of work-related disorders of the upper extremities: Washington state, 1987 through 1995.

OBJECTIVES: This study examined the claim incidence rate, cost, and industry distribution of work-related upper extremity disorders in Washington. METHODS: Washington State Fund workers' compensation claims from 1987 to 1995 were abstracted and categorized into general and specific disorders of gradual or sudden onset. RESULTS: Accepted claims included 100,449 for hand/wrist disorders (incidence rate: 98.2/10,000 full-time equivalents; carpal tunnel syndrome rate: 27.3), 30,468 for elbow disorders (incidence rate: 29.7; epicondylitis rate: 11.7), and 55,315 for shoulder disorders (incidence rate: 54.0; rotator cuff syndrome rate: 19.9). Average direct workers' compensation claims costs (medical treatment and indemnity) were $15,790 (median: $6774) for rotator cuff syndrome, $12,794 for carpal tunnel syndrome (median: $4190), and $6593 for epicondylitis (median: $534). Construction and food processing were among the industries with the highest rate ratios for all disorders (> 4.0). CONCLUSIONS: Upper extremity disorders represent a large and costly problem in Washington State industry. Industries characterized by manual handling and repetitive work have high rate ratios. The contingent workforce appears to be at high risk.

Absenteeism↗
PubMed1997

Injuries due to assaults on psychiatric hospital employees in Washington State.

In order to estimate rates and identify risk factors for assaults on employees of a state psychiatric hospital, we examined workers' compensation claims, hospital-recorded incident reports, and data collected in a survey of ward staff. Results revealed 13.8 workers' compensation claims due to assault per 100 employees per year. Assaults were responsible for 60% of total claims. Incident reports revealed 35 injuries due to assault per 100 employees per year. Survey data revealed 415 injuries due to assault per 100 employees per year. Of the respondents, 73% reported at least a minor injury during the past year. Assault management training in the past year was associated with less severe injuries. Working in isolation, the occupation of mental health technician, and working on the geriatric-medical hospital unit were associated with more severe injuries during the past year. Assaults on staff in psychiatric hospitals represent a significant and underrecognized occupational hazard.

Analysis of Variance↗
PubMed1997

Falls in construction: injury rates for OSHA-inspected employers before and after citation for violating the Washington State Fall Protection Standard.

This study examined the relationship between Washington's fall protection standard and injuries in construction workers. Workers' compensation claim rates for falls were examined for employers that were cited for violating the standard over the 1991-1992 period. Fall injury rates for the periods before and after inspections were compared. Claims for a control group of employers that had not been cited were also examined. For the 784 cited employers, the claim rate for compensable fall injuries decreased from 1.78 to 1.39 per 200,000 hours worked for the one-year periods before and after inspection. For the control group (n = 8,301), the claim rate decreased from 1.04 to 0.95 per 200,000 hours. Cited employers were 2.3 times as likely as control employers (p < 0.0001) to experience a claim rate reduction, after adjustment for employer size and type of business. Results suggested that industry-wide fall injury rates might be expected to decrease if more employers were inspected.

Accidental Falls↗
PubMed1997

Surveillance of work-related musculoskeletal injuries among union carpenters.

Combined data sources, including union administrative records and workers' compensation claims, were used to construct event histories for a dynamic cohort of union carpenters from Washington State during the period 1989-1992. Person-time at risk and the events of interest were stratified by age, sex, time in the union, and predominant type of carpentry work. Poisson regression techniques were used to identify subgroups at greatest risk of filing claims for a variety of musculoskeletal disorders defined by ANSI codes for body part injured and injury nature. Distinguishing different kinds of musculoskeletal disorders, even crudely with ANSI codes, led to different conclusions about the effects of the explanatory variables. Among older workers, the rates of fractures of the foot were higher, while rates of contusions of the hand and foot were lower. Women had higher rates of sprain/strains and nerve conditions of the wrist/forearm. Higher rates of injuries to the axial skeleton were seen among carpenters who did predominantly light commercial and drywall work, while piledrivers had lower rates of these injuries. Drywall workers had higher rates of sprains to the ankle/lower leg. Workers who were members of the union as long as four years had lower risks for the vast majority of musculoskeletal disorders studied. Similar patterns were seen for more serious claims that resulted in paid lost time from work.

Adolescent↗
PubMed1997

Assessing the role of the biomaterial Aquavene in patient reactions to Landmark midline catheters.

Landmark midline catheters (Menlo Care, Inc., Palo Alto, CA) provide peripheral venous access for the infusion of medications or fluids. They are constructed of an inner layer of polyurethane and an outer layer of the biomaterial Aquavene, a blend of polyurethane and polyethylene oxide to which butylated hyroxyanisole (BHA), butylated hydroxytoluene (BHT), and triallyl-s-triazine trione (TTT) are added. Once inside the vein, the Aquavene material becomes hydrated and the catheter swells resulting in minimal trauma to the vein. It is well recognized that some patients experience reactions to catheterization. Recent reports of hypersensitivity-like reactions in some patients catheterized with Landmark catheters have prompted the manufacturer to reexamine biocompatibility data and clinical data to assess whether Aquavene was the source of the patient responses. None of the biocompatibility studies provided by Menlo Care in support of U.S. registration and marketing of Aquavene-based catheters demonstrated any tendency for Aquavene or material extracted from Aquavene to invoke an immunological or toxicological response. Examination of potential catheter residuals revealed that significant amounts of BHA and BHT were unlikely to be released from the catheters during expected use. The amounts of polyethylene oxide and TTT expected to be released during the first few minutes after catheter insertion (when most of the patient reactions were reported) are almost 92,500 and 270,000 times lower, respectively, than nontoxic animal exposures. These analyses do not support chemically mediated toxicity as an explanation for the adverse events experienced by some patients. A review of the postmarket surveillance data on Aquavene-based catheters revealed that the reported events were not consistent with a hypersensitivity (immunogenic) response to the biomaterial. The rare reported adverse events tend to occur quickly, most often after flushing of the catheter, and resolve quickly, even when the catheter remains in place. Determining the frequency and severity of adverse events reported in association with the use of Landmark catheters will ultimately require a controlled prospective study, preferably one with a concurrent control group using alternative products.

Biocompatible Materials↗
PubMed1996

Antimicrobial practice. Development of guidelines for gentamicin dosing.

The performance of dosage guidelines for starting gentamicin therapy was evaluated prospectively in 50 patients with suspected or proven Gram-negative septicaemia and the results were compared with results from similar group of 50 patients for whom the guidelines were not followed. Peak concentrations were significantly higher when the guidelines were followed (7.2 (+/- 1.9) mg/L vs 5.7 (+/- 1.8) mg/L) but there was no difference in trough concentrations. Fifty-eight per cent of patients had both peak and trough concentrations within the target range (peak > 5 mg/L, trough < 2 mg/L) when doses were decided empirically; this increased to 96% when the guidelines were followed. However, use of the guidelines achieved peaks of > 7 mg/L in only 56% of patients. A revised protocol with higher doses given less frequently was therefore developed and a prospective assessment of its performance indicated that satisfactory concentrations were obtained in 96% of patients.

Anti-Bacterial Agents↗
PubMed1996

Musculoskeletal Disorders: Work-related Risk Factors and Prevention.

Work-related musculoskeletal disorders cause chronic pain and functional impairment, impose heavy costs on society, and reduce productivity. In this position paper from the Scientific Committee for Musculoskeletal Disorders of the ICOH, the most important risk factors at work are described. Work-related musculoskeletal disorders have high incidences and prevalences among workers who are exposed to manual handling, repetitive and static work, vibrations, and poor psychological and social conditions. The application of ergonomic principles in the workplace is the best method for prevention. International organizations should develop standards, common classifications, and terminologies. Surveillance systems should be further developed nationally and in workplaces, and more effort should be directed to information dissemination, education, and training.

Journal Article↗