RESUMO
BACKGROUND: Nonspecific chronic neck pain is a fairly common disorder that causes a great impact, and it is greatly influenced by psychosocial factors. Among a number of treatment modalities described for its management, the most common approach is based on manual therapy and specific therapeutic exercise, which have shown a moderate effect on subjects with chronic non-specific neck pain. However, the effect times of these treatments have not been accurately detailed. Our study aims to break down and compare the effects of two experimental treatments based on manual therapy and therapeutic exercise. METHODS: The short-term and mid-term changes produced by different therapies on subjects with non-specific chronic neck pain were studied. The sample was randomized divided into three groups: manual therapy, therapeutic exercise, and placebo. As dependent variables of our research, we studied (a) pain, based on the visual analog scale and the pressure pain threshold, and (b) cervical disability, through the Neck Disability Index (NDI). Outcomes were registered on week 1, week 4, and week 12. The findings were analyzed statistically considering a 5% significance level (P ≤ 0.05). RESULTS: No statistically significant differences (P 0.05) were obtained between the experimental groups, if they exist against the control group. Nonetheless, we found that manual therapy improved perceived pain before than therapeutic exercise, while therapeutic exercise reduced cervical disability before than manual therapy. Effect size (R2) shows medium and large effects for both experimental treatments. CONCLUSION: There are no differences between groups in short and medium terms. Manual therapy achieves a faster reduction in pain perception than therapeutic exercise. Therapeutic exercise reduces disability faster than manual therapy. Clinical improvement could potentially be influenced by central processes. TRIAL REGISTRATION: Brazilian Clinical Trial Registry, RBR-2vj7sw. Registered on 28 November 2018.