Summary of background data: Back schools may be effective in treating back problems, but there is conflicting evidence of the effect on prevention.
Objectives: To investigate if passive prone extensions of the back can prevent back problems.
Study design: Prospective, randomized controlled intervention trial.
Methods: In total, 314 male conscripts were randomized into two groups. After randomization, 65 conscripts dropped out for administrative reasons, leaving 249 conscripts to participate fully in the study. Data were collected through questionnaires at the start of military duty and after 10 months. All conscripts in the intervention group had one 40-minute theoretical lesson on back problems and ergonomics and had to perform passive prone extensions of the back daily during the rest of their military duty. The control group had no intervention. Outcome variables were as follows: 1) number of persons with self-reported back problems during the last 3 weeks; 2) number of persons with self-reported back problems during the last year; and 3) number of persons who reported having consulted the regiment medical physician with back problems during their military service.
Results: In an intention-to-treat analysis, significantly fewer persons in the intervention group versus those in the control group reported back problems during the last year (33% versus 51%), and the number needed to prevent was 6. Significantly fewer persons in the intervention group versus those in the control group consulted the regiment infirmary (9% versus 25%), and the number needed to prevent was 6.
Conclusion: It may be possible to reduce the prevalence rate of back problems and the use of health care services during military service, at a low cost, using passive prone extensions of the back motivated by a back school approach, including the theory of the disc as a pain generator and ergonomic instructions.