Low back pain – a leading work-related musculo-skeletal disorder
Low back pain (LBP) is one of the major problems among work-related musculo-skele- tal disorders. Its lifetime prevalence among workers and the general population is 60% to 80%, with a yearly incidence of 6% to 20%. Most episodes are mild and self-limited.
Approximately 90% recover spontaneously and return to activity within one month, 20% seek health care, and only about 10% of the affected workers seek compensation [1].
Epidemiologic studies have investigated the recovery time of workers with low back pain:
40% to 50% of them are back at work by 2 weeks, 70% to 80% return by 4 weeks. Those workers who are still absent from work at 6 months are at progressively higher risk for becoming chronically disabled [2]. The small number of cases that become chronic account for a large part of the compensation expenses [3]. Webster et al. stated that low- back injuries constitute 16% of all workers’ compensation claims, but consume 33% of all claim costs [4].
Work-related and personal risk factors
Work-related risk factors for back injuries have been identified, such as heavy physical work, repetitive work tasks, exposure to vibration, frequent bending and twisting, static work postures, and lifting or forceful movements [5]. Wanek et al. [6] stated that psy- chosocial stressors such as time pressure, conflicts with co-workers and superiors are also important. The frequency of chronic back pain, working conditions and requests for workplace modifications were investigated among 974 employers of a metal company.
Prolonged exposure to physical stressors was associated with a strongly elevated risk for chronic back pain. In addition, research has linked work-related musculo-skeletal disor- ders to stressful aspects of work organization, such as machine-paced work, inadequate
and low back pain
V. Fialka-Moser, M. Herceg and E. Hartter
work-rest cycles, wage incentives, time pressure, overload, low job control, low social sup- port, and repetitive work, and lack of task variability [7].
Garg et al. [8] identified personal risk factors such as age, gender, anthropometry, physical fitness and training, lumbar mobility, strength, medical history, years of employ- ment, smoking, psychosocial factors and structural abnormalities.
Factors affecting outcome of vocational rehabilitation and return to work time
For the physician in charge, a thorough medical history taking is very important for a proper diagnosis. It is also important for prognosticating and managing the individual’s return to work. A history of previous injuries on the job and recovery periods can be very helpful. An exact description of the incident is essential; the same is true for the work tasks and the frequency of performing these tasks. The nature of pain, the postures that induce difficulties, and the effects of medication should be inquired. The worker’s per- ception of his functional ability or rather disability is also important, because sometimes a return to light duty is possible and this would mean less absent workers on compensa- tion. The individual’s attitude towards the job may affect his/her speed of return to work;
the attitude towards the boss or work culture may be useful in making a prognosis.
Finally, work environment, job requirements, and the patient’s perception of the employer’s flexibility are important, since the worker is often expected to perform the original job to its full extent [2].
Selander et al. [9] reviewed publications from 1980 through to 2000 to overview fac- tors which are associated with return to work following vocational rehabilitation for pro- blems in the neck, back, and shoulders. A variety of (risk-)factors are associated with return to work in numerous ways.
Demographic factors are age, gender, nationality, income, level of education, marital status, living situation, legal claim working status and earlier sick leave.
Possible psychological and social factors would be self-confidence, life satisfaction, and level of experienced health, depression, health locus of control, cooperativeness, hypochondria, motivation and belief in return to work as well as social situation.
Medical factors are medical history, level of disease/injury severity, pain, and neuro- logical symptoms during treatment as well as activities of daily living.
Furthermore factors can also be either rehabilitation related (type of rehabilitation measure, timing of vocational rehabilitation, understanding of work place, programme completion, patient influence, satisfaction with rehabilitation programme), or work- place related (changing jobs, working environment, modified work, early return to work- place, unscheduled breaks, vocational sector, job seniority, work history, size of work- place, public sector vs. private) but also benefit-system-related (disability benefit status, level of compensation, unemployment rates).
An important point is to carefully match workers and jobs. To achieve this end, a job analysis should describe the physical requirements for the tasks involved. Standardised
tests of the essential functions of the specific job should exist. Work stations and tasks should be ergonomically designed, taking into account variations in physical size and capacity.
Gender differences, i.e., gender-specific vulnerabilities and advantages should also be considered. Headapohl [10] stated that there are differences not only between sexes but also among individuals of the same sex. An increasing number of women are now enga- ged in traditionally male occupations. Gender, pregnancy and individual differences have to be taken into account in job placement, worker protection and the ergonomics of accommodation.
Prevention and intervention
To maximize safety and efficiency at the workplace, Scheer et al. [11] recommended ergonomic assessment which included job analysis from the biomechanical, physiologi- cal and physical viewpoint. This review identified workers’ training (fitness and stret- ching exercise, back support belts, postural instruction and back goniometric warning alarms), selection of workers (matching of workers’ capacity and job requirements) and job/workplace redesign (to eliminate or lessen unfavourable mechanical stresses) as the three most commonly described categories of ergonomic intervention. Workplace rede- sign, using both engineering (directly affecting the job) and administrative methods (affecting the worker), is likely to be the most effective intervention.
A review of 14 randomized controlled trials made by Staal et al. [12] showed the need for effective treatment interventions for low back pain. The aim was to prevent chronic disability and achieve return to work. The results revealed different approaches using various physical exercises (muscle strengthening, coordination exercises, ROM exercises for the spine, cardiovascular fitness programs and reduction of muscle tension), educa- tion (to increase the patients’ understanding of their disorder and treatment), and beha- vioural treatments (based on the gate control theory and/or the operant conditioning hypothesis). No concepts for ergonomic measures were presented [12].
Investigations by Schmidt et al. [13] demonstrated a significant impact of vocational rehabilitation (provided at the rehabilitation centre) and working on a trial basis (real work environment) on employment after rehabilitation. The likelihood of return to work was two-fold higher for people who participated in vocational rehabilitation than for those who did not, and three-fold higher for those who were involved in both vocational rehabilitation and work on trial than for those who were only involved in a vocational rehabilitation program. Thus, the study suggests that programs specifically aimed at pro- moting employment for persons with disabilities are effective, especially when they take place both in a laboratory and a natural setting.
Torstensen et al. [14] demonstrated that medical exercise therapy and conventional physical therapy reduce the costs of low back pain, even in chronic cases. Håland Haldorsen et al. demonstrated that multidisciplinary treatment (cognitive behavioural modification, education, exercise and occasional workplace interventions) was effective
in regard of returning to work, when provided for patients who were most likely to bene- fit from the treatment [15]. Butterfield et al. found out that injured workers who stop- ped exercising after a back injury had longer periods of disability than those who remai- ned more active [16].
Gatchel was able to show the treatment and cost effectiveness of an early intervention program for acute LBP patients. Seven-hundred patients with acute low back pain were screened for their high risk or low risk status for developing chronicity. An early screen- ing and intervention program (psychology, physical therapy, occupational therapy and case management) among patients with acute low back pain could help to prevent high- risk patients from becoming chronic and also save costs [17].
The role of the occupational or company physician
Obviously the key problems of occupationally acquired or occupation-associated LBP are an ergonomic and satisfactory work place on the one side (primary prevention), and early intervention on the other (secondary prevention). Ideally both should be provided in close association to the work place. Recent literature indicates that the company phy- sician or occupational physician might substantially contribute to the management of both these problems [18, 19]. He/she is familiar with the work-place situation and the resulting physical as well as psychomental stress and strain on the employees and usually has knowledge about their health complaints at an early stage. Ideally he/she will make suggestions on ergonomic workplace (re)design, on establishment of workplace safety and healthy conditions of work, risk-management, instruct employees about safe work techniques, as well as health hazards, and provide consulting about measures of general as well as personal primary and secondary prevention. Occupational physicians should recognize health complaints associated with or with relevance for the work-place at the very early stage and provide or initiate adequate intervention (workplace-oriented, medi- cal treatment). Integration of the occupational physician or company physician into the process of vocational rehabilitation might substantially reduce the time until its onset, the return to work time and the success rate [19].
Conclusions
This overview clearly indicates the need for a broad approach to the subject of vocational rehabilitation. The need for improvement has been emphasised in many studies. Greater efficiency, cost containment (less compensation and sick leave) as well as effective strate- gies for prevention, intervention and treatment methods are important topics [12, 17, 20].
Patients still have to accept prolonged waiting periods and processing times until occupational rehabilitation can start. To improve communication between rehabilitation centres and vocational training centres, cooperative approaches between these institu- tions were initiated in Germany. This resulted in a considerable acceleration of proce-
dures. Occupational reintegration of insured patients was improved to a high degree. The key term here is “occupationally orientated medical rehabilitation” [21].
Many different factors have to be taken into account. Communication between wor- kers, business enterprises, occupational physicians, insurance companies, health care pro- viders and the rehabilitation team is of great importance. From the rehabilitation point of view, it takes a team effort between doctors, therapists (physiotherapy and occupational therapy) as well as psychologists and social workers to provide the best possible care.
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