Effect of strength training in addition to general exercise in the rehabilitation of patients with non-specific neck pain. A randomized clinical trial.

Background: The optimal type of exercise protocol in the physical rehabilitation of non-specific neck pain has not yet been established. Furthermore, the role of fear-avoidance belief in the maintenance of pain and disability has been highlighted. Research indicates that exercise may be a means to reduce fear-avoidance belief, but evidence is scarce.
Aim: To compare the effect of two different exercise programs on pain, strength and fear-avoidance belief.
Design: Randomized clinical trial.
Setting: A specialized outpatient hospital clinic in Denmark.
Population: Twenty-three men and 60 women on sick leave due to non-specific neck pain.
Methods: Participants were randomized to either general physical activity (GPA group) or GPA and additional strength training of the neck and shoulder (SST group). The primary outcome was pain intensity. Secondary outcomes were muscle strength of the neck and shoulder and fear-avoidance belief.
Results: Pain was significantly reduced within groups with a median of -1 (IQR: -3 to 0, P<0.001) in the SST group and -1 (IQR: -4 to 1, P=0.046) in the GPA group. The difference between groups was not significant. Changes in strength did not differ between groups. Both groups experienced significant increases in neck flexion strength of 14.7 N (IQR: -1 to 28.4, P=0. 001) in the SST group and 6.9 N (IQR: -4.9 to18.6, P=0.014) in the GPA group. Furthermore, the SST group achieved an increase of 18.6 N (IQR: -2.6 to 69.7, P=0.005) in neck extension. Fear-avoidance beliefs improved with 6 (IQR: 3 to 12, P<0.001) in the SST group, while the GPA group improved with 3 (IQR: 0 to 8, P=0.004). This between-group difference was significant (P=0.046).
Conclusion and Rehabilitation Impact: This study indicates that in rehabilitation of subjects severely disabled by non-specific neck pain, there is no additional improvement on pain or muscle strength when neck exercises are given as a home-based program with a minimum of supervision. However, strength training of the painful muscles seems to be effective in decreasing fear-avoidance beliefs.