Study design: Randomized controlled trial.
Objective: This is the companion study to a previous publication that presented 8-week pain, disability, and trunk muscle motor control results. The objective of this study was to compare the effect of 8 weeks of specific trunk exercises and stationary cycling on outcomes measures of catastrophizing and fear-avoidance beliefs (FAB) in patients with chronic nonspecific low back pain, and provide 6-month outcome data for all self-report measures.
Summary of background data: It is thought that any form of moderate-to-vigorous physical activity is sufficient to address catastrophizing and FAB, and concomitant levels of pain and disability.
Methods: Sixty-four patients with low back pain were randomly assigned to 8 weeks of specific trunk exercise group (SEG), or stationary cycling group (CEG). Self-rated pain, disability, catastrophizing and FAB scores were collected before, immediately after (8 wk), and 6 months after the training program. Clinically meaningful improvements were defined as greater than a 30% reduction from baseline in pain and disability scores. "Intention-to-treat" principles were used for missing data. Per-protocol analysis was performed on participants who attended at least two-thirds of the exercise sessions.
Results: At 8 weeks, disability was significantly lower in the SEG compared with the CEG (d = 0.62, P = 0.018). Pain was reduced from baseline in both the groups after training (P < 0.05), but was lower for the SEG (P < 0.05). FAB scores were reduced in the SEG at 8 weeks, and in the CEG at 6 months. No between-group differences in FAB scores were observed. Similar reductions in catastrophizing in each group were observed at each time point. At 6 months, the overall data pattern suggested no long-term difference between groups. Per-protocol analysis of clinically meaningful improvements suggests no between-group differences for how many patients are likely to report improvement.
Conclusion: Inferential statistics suggest greater improvements at 8 weeks, but not 6 months, for the SEG. Inspection of clinically meaningful changes based on a minimum level of adherence suggests no between-group differences. If a patient with low back pain adheres to either specific trunk exercises or stationary cycling, it is reasonable to think that similar improvements will be achieved.
Level of evidence: 2.