Current issues of ACP Journal Club are published in Annals of Internal Medicine


Therapeutics

Graded activity and operant conditioning for low back pain

ACP J Club 1992 Sept-Oct;117:45. doi:10.7326/ACPJC-1992-117-2-045


Source Citation

Lindström I, Ohlund C, Eek C, et al. The effect of graded activity on patients with subacute low back pain: a randomized prospective clinical study with an operant-conditioning behavioral approach. Phys Ther. 1992 Apr;72:279-93.


Abstract

Purpose

To determine whether a graded, individualized activity program for industrial workers with subacute, nonspecific, mechanical low-back pain can reduce sick leave.

Design

2-year randomized controlled trial.

Setting

Physical therapy clinic in Sweden.

Patients

Consecutive patients (103 industrial workers; mean age, 41 y; 71 men) were eligible if they had been on sick leave for 6 weeks with a new episode of low back pain. Exclusion criteria were disk herniation requiring surgery; spondylolisthesis; stenosis; instability > 4 mm on flexion-extension radiographs; previous back surgery; vertebral fractures; tumors; inflammatory diseases; psychiatric diagnoses; pregnancy; and drug abuse.

Intervention

All patients received usual medical care. In addition patients in the activity group (n = 51) received an individualized program that included measurement of functional capacity (mobility, strength, and fitness); a workplace visit to assess work demands; education emphasizing back structure and function; and a submaximal, gradually increased exercise program. The exercise program, done in the company recreation department 3 days per week, used operant conditioning and included endurance and strength training, lifting and fitness exercises, walking, jogging, swimming, and gymnastics. Patients in the control group (n = 52) had no placebo program.

Main outcome measures

An orthopedic surgeon, social worker, and physiotherapist examined all patients initially and at 1 and 2 years to measure pain, function, and level of disability. Return-to-work data came from government social insurance files.

Main results

The rate of return to work in the activity group was faster (P = 0.03). At 6 weeks 29 patients (59%) in the activity group and 21 (40%) in the control group had returned to work, and at 12 weeks the rate was 41 (80%) in the activity group and 30 (58%) in the control group. The mean time to return to work was 10 weeks for the activity group and 15 weeks for the control group. During year 2, mean time loss in the activity group was 12.1 weeks compared with 19.6 weeks for the control group (P = 0.05).

Conclusion

Patients with subacute, nonspecific, mechanical low-back pain who received a graded, individualized exercise program returned to work earlier and had less sick leave than patients receiving standard care.

Sources of funding: Arbetsmarknadens försäkringsaktiebolag (AFA), Volvo Company, AMF-Trygghets forsikring; Greta and Einar Asker Foundation; Bertha and Felix Neuberg Foundation.

Address for article reprint: Ms. I. Lindström, Department of Orthopaedics, University of Göteborg, Sahlgren Hospital, S-413 45 Göteborg, Sweden.


Commentary

Chemonucleolysis and Disk Surgery for Lumbar Disk Herniation

The common terminology "low-back pain" emphasizes pain rather than disability or handicap, a distinction that has not been productive. These 2 studies assess strategies to reduce the disability or handicap.

The sound methods of these studies minimize bias and ensure that the differences reported are real. The clinician, however, must evaluate whether the studies have clinical significance and whether they will actually benefit patients. In the study by Muralikuttan and colleagues a significant advantage of surgery over chemonucleolysis was identified at 6 weeks and 3 months but not at 1 year. The participation rate at both 6 weeks and 3 months was 80% (18 patients not assessed) compared with 96% assessed at 1 year. Unequal distribution between groups could account for the early differences reported or could have obscured greater differences. Clinically the differences observed seem borderline.

Although the groups did not differ after 1 year, composite scores for both treatments were improved over entry status with respect to disability, impairment, and leg pain. There was minimal improvement in psychological score and none for back pain. The latter reinforces the impression that such treatment may not substantially alter back pain.

The advantages of surgical treatment were clear: It was less expensive; the failure rate was less for those receiving surgery (2% vs. 21%; P = 0.02); and surgery might have prevented 4 of the 9 chemonucleolysis failures. Although not statistically significant, the proportion free from pain in the surgical group was higher at year end (31% vs. 18%). Is either treatment superior to conservative management? Perhaps it is in the short term. The classic study by Weber (1), with similar patients, showed better results for surgery over conservative management at 1 year and nonsignificant improvement at 4 years; the groups did not differ at 10 years.

The study by Lindström and colleagues involved a group of patients with the commonest back problem—nonspecific, mechanical low-back pain. Appropriately selected Volvo workers, off work for more than 8 weeks, were randomly assigned either to receive a complex management package or to be in a control group receiving standard medical care. A difference from other studies of activation was the use of operant conditioning techniques; for example, instead of exercising to tolerance (in which rest or time off is contingent on experiencing pain), a quota for each exercise was determined from the functional capacity test, and workplace visits and exercises were done based on specified increasing quotas (non-pain-contingent).

The activity program resulted in statistically and clinically significant short- and long-term benefits. These benefits are consistent with recent studies indicating that physical activity focused on a specific goal is effective in reducing back disability. It is not possible from the study report to isolate specific components of the intervention that may have been major determinants for the differences observed, but potentially powerful additions to graded activity included operant conditioning and direct involvement with the work and workplace. The latter could substantially influence earlier return to work. Although one cannot be sure which components of the intervention are crucial, it is clear that multidisciplinary, directed activation can reduce back disability.

Edward S. Gibson, MD
Dofasco Medical Centre Hamilton, Ontario