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American Pain Society
4700 W Lake Ave
Glenview, IL 60025
Robert J. Gatchel, PhD, Department Editor
Michael Feuerstein, PhD; Grant D. Huang, BA
Editor's note: The opinions or assertions expressed herein are the private views of the authors. They are not official, nor do they reflect the views of the Uniformed Services University of the Health Sciences or the Department of Defense.
By the time patients gain referral to a pain specialist, they have typically undergone evaluation and treatment by many providers, have received many independent medical evaluations, and are fatigued, depressed, frustrated, angry, and fearful--and these factors can impede a positive clinical outcome. The frequently adversarial nature of a work injury and subsequent workers' compensation claim can also negatively affect the patient-provider relationship and further limit a positive outcome. This sequence of events, which most pain providers have witnessed at one time or another, need not occur.
We propose that by applying a scientifically based approach to risk assessment and intervention it is possible to prevent the prolonged pain, disability, and distress associated with persistent OMDs. Specifically, we discuss some of our recent findings as well as those of others who are working toward the prevention of pain-related work disability. Furthermore, we highlight the preliminary implications of this research for current pain practice.
A broad category of disorders constitutes occupational low back pain (Frymoyer & Andersson, 1991). Examples of the more common disorders include disk degeneration, disk herniation with or without myelopathy, spinal stenosis, segmental instability, and nonspecific back pain (i.e., sprain or strain). Work-related upper-extremity disorders (WRUEDs) also include a wide range of diagnoses in the fingers, hands, wrists, forearms, elbows, shoulders, and neck (Rempel, Harrison, & Barnhart, 1992). Some common WRUEDs include mononeuritis of the upper limb (e.g., carpal tunnel syndrome), peripheral enthesopathies (e.g., medial and lateral epicondylitis), synovitis and tenosynovitis (e.g., trigger finger, radial styloid tenosynovitis [or de Quervain's disease]), as well as myalgia and myositis.
Although significant debate regarding the specific etiology of these disorders is ongoing, cross-sectional studies suggest that variables associated with OMDs are medical, ergonomic, and psychosocial in nature. As with non-work-related back disorders, a range of medical factors can play a role in the etiology of occupational back pain and disability. Some of these include degenerative changes in the spine, spinal stenosis, disk herniation, spondylolysis, spondylolisthesis, spine trauma, and inflammation of noninfectious etiology (Frymoyer & Andersson, 1991). With regard to occupational upper-extremity disorders, medical factors of potential etiological significance include acute trauma, rheumatoid arthritis, diabetes mellitus, hormonal factors, obesity, and congenital defects (Hales & Bernard, 1996; Travers, 1988). Research on ergonomic factors has indicated that OMDs are often associated with prior exposure to biomechanical or metabolic work demands that involve excessive force, awkward or extreme postures, repetition, vibration, and temperature extremes (Armstrong et al., 1993; Marras et al., 1995). Psychosocial factors related to low back pain arising in the workplace include high levels of perceived job demands, time pressure, and low social support by coworkers and superiors (Bongers, de Winter, Kompier, & Hildebrandt, 1993). Psychosocial factors associated with workplace-related upper-extremity disorders include high perceived workload, time pressure, monotonous work, and lack of social support (Bongers et al.).
Shifting from studies of workers to those of patients, we note that Mathis, Gatchel, Polatin, Boulas, and Kinney (1994) found that more patients with chronic carpal tunnel syndrome displayed anxiety-related disorders than did patients with chronic back pain, who are more likely to suffer depressive and substance abuse disorders. Also, patients who could not work because of occupation-related upper-extremity disorders tended to report higher levels of pain and fear of pain (with a greater tendency to “catastrophize") and lower levels of perceived control over pain (Himmelstein et al., 1995).
Over the past two decades, several approaches have emerged for preventing the development of OMDs, treating the symptoms and their suspected underlying causes, and rehabilitating injured workers for their return to work. These approaches include back schools, interactive software prompting rest breaks and illustrating stretching exercises, ergonomic training programs, a work-site evaluation of ergonomic stressors, workplace modifications, passive and active physical therapy, medical management, functional restoration, and occupational rehabilitation. Although it is beyond the scope of this report to provide a detailed review of these various approaches, we emphasize that few of them currently address all three of the accepted OMD-related (i.e., ergonomic, medical, and psychosocial) factors in an effective manner. Functional restoration and occupational rehabilitation do consider medical, ergonomic, and psychosocial factors; however, these approaches serve primarily to intervene at a later stage in the recovery process. They are relatively complex to administer, costly, and perhaps are not cost-effective for less chronic cases. Consequently, there is a need to develop innovative approaches that will begin earlier in the recovery process and that target the many factors affecting pain, distress, functional limitations, and work disability.
The conceptual framework and empirical support that provide the basis for functional restoration and occupational rehabilitation conceivably could apply earlier in the injury recovery process. However, we reasoned that a more empirical approach to disability prevention would use multidimensional models of OMDs and disability as the foundation for identifying specific workplace and individual risk factors and to develop interventions targeted at these factors.
In an effort to develop an organizationally based integrated disability prevention program, we first studied an administrative database from the work organization of interest (i.e., the U.S. Army) to identify the most prevalent diagnoses associated with disability (Feuerstein, Berkowitz, & Peck, 1997). These diagnoses were musculoskeletal in origin and included musculoskeletal limitation of motion, degenerative arthritis, and lumbosacral strain (we were limited by the lack of availability of specific ICD-9 codes in the database). Afterward, we isolated jobs associated with an increased risk for these musculoskeletal disabilities. The high-risk jobs were not simply those with heavy physical demands but tended to vary in the extent of both physical and psychosocial demands. We used a second administrative data source, the Health Risk Appraisal (HRA) (a questionnaire that U.S. Army personnel fill out themselves to assess cardiovascular risk), to identify the demographic, physical, individual psychosocial, and occupational variables predictive of disability. HRA data were obtained 1-3 years prior to the onset of disability. Specific predictors of back disability were age (odds ratio [OR] = 1.1), lower employment status (OR = 4.1), infrequently engaging in aerobic exercise (OR = 2.2), perception of increased occupational stress (OR = 2.7), low amounts of social support (OR = 5.1), and increased worries (OR = 2.2) (Berkowitz & Feuerstein, 1997, under review). Variables that predicted upper-extremity-related disability were age (OR = 1.1), ethnicity (OR = 1.5), lower employment status (OR = 4.4), and frequency of occupational stress (OR = 2.5) (Huang, Feuerstein, Berkowitz, & Peck, 1997, under review). It should be noted that a risk factor with an OR above 1 indicates that a person with the indentified risk factor is more likely to develop the outcome than someone who does not have the risk factor. For example, a risk factor with an OR of 3 indicates that a person with the risk factor is three times more likely to develop the outcome than a person who does not have the risk factor.
Other studies have found that several additional variables predict back disability. These variables include job characteristics, perception of fault for injury, type of accident, and past hospitalizations (Oleinick, Gluck, & Guire, 1996). Gatchel, Polatin, and Kinney (1995) also reported that higher levels of pain and perceived disability, heightened reactivity to stress (i.e., a high score on the hysteria scale of the Minnesota Multiphasic Personality Inventory), and the presence of a personality disorder predicted continued work disability at 6 months after the initial assessment. In the case of occupational upper extremity disorders, factors such as less time on the job; a history of prior surgeries; an absence of acute trauma; an indeterminate versus a specific diagnosis; higher levels of “catastrophizing" and anger toward an employer; lower levels of perceived control; and involvement with an attorney tended to occur with cases in which patients had a work-related disability (Himmelstein et al., 1995). In the same study, patients unable to work for more than 6 months were older, had jobs that involved repetitive or forceful movements and awkward postures, had higher levels of fear of pain and less perceived control over pain, used more coping strategies, enjoyed work tasks less, and had engaged the services of an attorney. Studies of work-disabled patients with carpal tunnel syndrome have found that ergonomic factors such as self-reported repetitive hand-and-wrist bending on the job predict disability (Blanc, Faucett, Kennedy, Cisternas, & Yelin, 1996). Also, depression and anxiety predict work absence resulting from carpal tunnel syndrome (Katz et al., 1997).
Based on these findings, we are in the process of developing a secondary prevention program, which focuses on symptomatic workers with a history of lost time resulting from a musculoskeletal disorder. This approach includes a screen that identifies workers in high-risk jobs whose individual factors can increase their likelihood for disability. After we have identified these workers, an intervention that targets reducing multiple risk factors and that combines therapeutic exercise (Linton, Hellsing, & Andersson, 1993), ergonomic assessment and intervention (Johns, Bloswick, Elegante, & Colledge, 1994), and problem solving (D'Zurilla & Nezu, 1990) will be implemented. Although outcome studies that support the use of individual components of this intervention for certain outcomes exist, we need to evaluate the long-term outcomes of such an integrated strategy.
Research continues to identify the predictors of prolonged pain and disability in injured workers with musculoskeletal disorders, and a pattern of prognostic indicators is emerging. The research for back disorders is more developed than that for upper-extremity disorders, but it is possible to generate a list of factors associated with delayed functional recovery. We provide a list of these factors in Table 1 for easy reference. Note, however, that this table is not comprehensive. Table 2 lists the specific questions from the Health Risk Appraisal that are significant predictors of disability. Further research will determine how best to use this information in treatment. Nevertheless, an awareness of such factors in clinical decision making should facilitate referral to appropriate providers who can address these factors, thereby optimally enhancing outcomes.
| BACK | UPPER EXTREMITY | |
MedicalHistory of back pain |
MedicalCongenital defects |
|
ErgonomicLifting frequency |
ErgonomicRepetitive and/or forceful exertions |
|
PsychosocialLack of job satisfaction |
PsychosocialHigh perceived workload |
|
| ITEM | RESPONSES | |
| How often do you perform at least 20 minutes of nonstop aerobic activity? | Rarely/never, once or twice a week, three or more times a week | |
| How often do you feel that your present work situation is putting you under too much stress? | Never, seldom, sometimes, often | |
| How often are people available for you to turn to for support in bad moments or illness? | Never, hardly ever, sometimes, always | |
| In the past year, how often have worries interfered with your daily life? | Never, seldom, sometimes, often | |
| Note. Response options that indicate increased risk are in boldface type. | ||
Armstrong, T.J., Buckle, P., Fine, L.J., Hagberg, M., Jonsson, B., Kilbom, A., Kuorinka, I.A.A., Silverstein, B.A., Sjogaard, G., & Viikari-Juntura, E.R.A. (1993). A conceptual model for work-related neck and upper-limb musculoskeletal disorders. Scandinavian Journal of Work, Environment, & Health, 19(2), 73-84.
Berkowitz, S.M., & Feuerstein, M. (1997) Predicting long-term disability from occupational low back pain. Manuscript submitted for publication.
Blanc, P.D., Faucett, J., Kennedy, J.J., Cisternas, M., & Yelin, E. (1996). Self-reported carpal tunnel syndrome: Predictors of work disability from the National Health Interview Survey Occupational Health Supplement. American Journal of Industrial Medicine, 30, 362-368.
Bongers, P.M., de Winter, C.R., Kompier, M.A.J., &
Hildebrandt, V.H. (1993). Psychosocial factors at work and musculoskeletal disease. Scandinavian Journal of Work, Environment, & Health, 19, 297-312.
D'Zurilla, T.J., & Nezu, A.M. (1990). Development and preliminary evaluation of the social problem-solving inventory. Psychological Assessment, 7(2), 156-163.
Feuerstein, M., Berkowitz, S.M., & Peck, C.A. (1997).
Musculoskeletal-related disability in U.S. Army personnel: Prevalence, gender, and military occupational specialties. Journal of Occupational Environmental Medicine, 39, 68-78.
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Himmelstein, J.S., Feuerstein, M., Stanek, E.J., Koyamatsu, K., Pransky, G.S., Morgan, W., & Anderson, K.O. (1995). Work-related upper-extremity disorders and work disability: Clinical and psychosocial presentation. Journal of Occupational Environmental Medicine, 37, 1278-1286.
Huang, G.D., Feuerstein, M., Berkowitz, S.M., & Peck, C.A. (1997). Occupational upper extremity-related disability: Demographic, physical, and psychosocial factors. Manuscript submitted for publication.
Johns, R.E., Bloswick, D.S., Elegante, J.M., & Colledge, A.L. (1994). Chronic, recurrent low back pain: A methodology for analyzing fitness for duty and managing risk under the Americans with Disabilities Act. Journal of Occupational Medicine, 36, 537-547.
Katz, J.N., Keller, R.B., Fossel, A.H., Punnett, L., Bessette, L., Simmons, B.P., & Mooney, M. (1997). Predictors of return to work following carpal tunnel release. American Journal of Industrial Medicine, 31(1), 85-91.
Linton, S.J., Hellsing, A.L., & Andersson, D. (1993).
A controlled study of the effects of an early intervention on acute musculoskeletal pain problems. Pain, 54, 353-359.
Marras, W.S., Lavender, S.A., Leurgans, S.E., Fathallah, F.A., Ferguson, S.A., Allread, W.G., & Rajuie, S.L. (1995). Biomechanical risk factors for occupationally related low back disorders. Ergonomics, 38, 377-410.
Mathis, L.B., Gatchel, R.J., Polatin, P.B., Boulas, H.J., & Kinney, R.K. (1994). Prevalence of psychopathology in carpal tunnel syndrome patients. Journal of Occupational Rehabilitation, 4(4), 199-210.
Oleinick, A., Gluck, J.V., & Guire, K.E. (1996). Factors affecting first return to work following a compensable occupational back injury. American Journal of Industrial Medicine, 30, 540-555.
Rempel, D.M., Harrison, R.J., & Barnhart, S. (1992).
Work-related cumulative trauma disorders of the upper extremity. Journal of the American Medical Association, 267, 838-842.
Travers, P.H. (1988). Soft tissue disorders of the upper extremities. Occupational Medicine,3(2), 271-283.
Michael Feuerstein is professor in the department of medical and clinical psychology and professor in the department of preventive medicine and biometrics at the Uniformed Services University of the Health Sciences in Bethesda, MD. He is also clinical professor in the department of psychiatry at Georgetown University Medical Center in Washington, DC. Grant Huang is a graduate fellow in the department of medical and clinical psychology at the Uniformed Services University of the Health Sciences in Bethesda, MD.
