Background: Tai Chi is emerging as a promising treatment for a variety of pain conditions, including chronic nonspecific neck pain. Given this trend, it is important to better understand the dose-response relationship and how pain, anxiety, and depression impact this relationship. Method: This secondary analysis used data from the Tai Chi arm (age = 52.03 ± 10.92 years; 73.68% female; n = 38) of a randomized controlled trial for chronic nonspecific neck pain. The authors tested whether (1) greater home practice time or cumulative practice time during the intervention predicted greater post-treatment reductions in neck pain intensity and (2) reporting greater neck pain intensity during the current week relative to other weeks was associated with lower home practice time during the current week. Post hoc analyses were conducted to evaluate whether baseline anxiety and depression levels moderated the association between weekly pain intensity and weekly home practice time. Results: While cumulative Tai Chi practice time (i.e., home practice + class time) was associated with post-treatment reductions in neck pain intensity, home practice time alone was not associated with post-treatment reductions in neck pain. Participants with low and moderate baseline anxiety were found to practice less than usual on weeks when pain intensity was worse, while participants with high baseline anxiety were found to practice more than usual on weeks when pain intensity was worse. Baseline depression levels did not moderate the effect of weekly pain intensity on weekly home practice time. Conclusions: Combined class and at-home exposure to Tai Chi appears to be critical to reductions in chronic nonspecific neck pain. In addition, anxiety may be an important characteristic that partially governs the dose-response relationship in participants with chronic nonspecific neck pain. Clinical Trial Registration: NCT02222051.
Keywords: Tai Chi; anxiety; depression; home practice time; neck pain.