Objective: To evaluate the effectiveness of specific lumbar extensor training compared with regular physical therapy (PT) in workers with nonspecific nonacute low back pain (LBP).
Design: A multicenter randomized controlled trial with 1-year follow-up.
Setting: PT department in (military primary care) health centers.
Participants: Predominantly male soldiers (N=129) with 4 weeks or more of low back complaints who were referred by the health center's general practitioner for PT (mean age, 35.9+/-10.8 y; range, 20-56 y), of whom 127 randomized participants were included in the analyses. One patient withdrew because of adverse effects during treatment.
Interventions: Participants were assigned to 1 of 2 treatment programs: (1) a 10-week device-supported isolated lumbar extension training, twice a week, or (2) regular PT, mainly consisting of exercise therapy and aerobic activities.
Main outcome measures: Functional status (Roland-Morris Disability Questionnaire, Patient-Specific Functional Scale) and global perceived effect were assessed in the short term (5 wk, 10 wk) and long term (6 mo, 12 mo).
Results: Both groups showed a favorable development in main outcomes over time: short-term improvements (after 10 weeks of treatment) remained stable or even slightly increased throughout the 12-month follow-up. No significant differences between the 2 groups were shown for any of the outcome measures, at any time.
Conclusions: Consistent with prior evidence, specific back strengthening does not seem to offer incremental benefits in LBP management compared with regular PT care that mainly consists of general exercise therapy. (ISRCTN identifier ISRCTN19334317.)