Objective: The purpose of this study was to analyze the influence of thoracic spinal manipulation (SM) on autonomic modulation and heart rate in patients with rotator cuff tendinopathy.
Methods: The design of the study was quasi-experimental. Participants were divided into 3 study groups: the asymptomatic group (n = 30), which received SM; the tendinitis group (TG, n = 30), which received SM; and the placebo group (PG, n = 30), which received placebo manipulation. Heart rate variability was analyzed with an electrocardiogram before and after intervention. For intragroup analysis, the paired Wilcoxon test was used to compare the means (pre vs post) of sex and age divided into 5 age groups. The Kruskal-Wallis test was employed for analysis between the groups, and a significance level of 5% was adopted.
Results: The TG demonstrated an increase in respiratory rate (mean of the selected intervals corresponding to parasympathetic activity) post intervention for both sexes (P = .04). Heart rate exhibited reduction post intervention in women in the TG (P = .05). The PG demonstrated an increase in respiratory rate post intervention for both sexes (female P = .01; male P = .02). In the age groups, only the PG presented any difference in the 40- to 50-year and 50- to 60-year age groups (P = .03) for the same variable. Heart rate exhibited a reduction post intervention in women in the PG (P = .01) and a reduction in the 50- to 60-year age group (P = .04). No difference in the studied variables was observed in the asymptomatic group, and there were no differences among the groups.
Conclusions: Upper thoracic SM does not directly influence autonomic modulation or heart rate.
Keywords: Autonomic Nervous System; Heart Rate; Manipulation, Spinal; Rotator Cuff; Tendinopathy.